Going covert: a security step above encryption

CQT's Valerio Scarani and Juan Miguel Arrazola have shown that two parties can hide a quantum signal sent between them within background noise: keeping secret not only the contents of their message but also the fact that they are in conversation. The work is published in Physical Review Letters.
Read more.


Fluorescent concentric triangles

NUS physicists have discovered fluorescent concentric triangles in an atomically thin layer of semiconductor for potential optoelectronic applications. A team led by Prof Chorng Haur SOW devised a method to fabricate in-plane periodical and lateral homojunctions in a WS2 monolayer.
Read more.


Super-resolution imaging using MeV ion beams

A research team led by Prof Andrew BETTIOL from the Centre for Ion Beam Applications (CIBA) in the Department of Physics, NUS has constructed a system for simultaneous fluorescence and structural imaging of whole cells by using a beam of highly focused (MeV) ions.
Read more.


Solution-processable conducting films with extreme work functions

A team led by Prof Peter HO and Dr Rui-Qi PNG from the Department of Physics, and Prof Lay-Lay CHUA from the Department of Chemistry, has shown that this process can be exploited to produce doped conducting polymer films with ultrahigh and ultralow work functions which are suitable for deployment in practical device structures by solution processing.
Read more.


Tortuous path to nanocrystals

A team of researchers from NUS, the Agency for Science Technology and Research and the University of Chicago, co-led by Prof Utkur MIRSAIDOV and Prof Duane LOH, both from the Department of Physics and Department of Biological Sciences have revealed the complex and elusive steps in crystallising nanocrystals from solution.
Read more.


Polarons for flexible electronics

A team led by A/Prof Peter HO and Dr Rui-Qi PNG from the Department of Physics, together with Prof Lay-Lay CHUA from the Department of Chemistry, has systematically demonstrated that the workfunction in some new doped organic semiconductors can be made anomalously deeper than its ionisation potential.
Read more.


Parallelised computation lens goes open-source

In a project led by Asst/Prof Duane LOH from the Department of Physics at NUS, physicists from the Centre for Free-electron Laser (Hamburg, Germany) and Cornell University (Ithaca, NY, USA) have published the first open-source x-ray laser-based computational lenses to image free-standing proteins in solution.
Read more.


High photoconductivity from hybrid bilayer

A team led by Prof Chorng Haur SOW, from the Department of Physics, NUS has developed a method to "heal" the defects present in the WSe2 monolayers. They developed effective methods for enhancing the performance of a WSe2 monolayer photodetector using laser tailoring and perovskite functionalisation.
Read more.


Verified: super-resolution imaging technique

CQT experimentalists first to test novel optical method invented by NUS colleagues. A novel technique to measure the separation of two lights sources, no matter how close they are, was first tested by researchers at the Centre for Quantum Technologies.
Read more.


View on DNA micromechanics through the quantum physics' matrix

A research group led by A/Prof Yan Jie from Department of Physics and Mechanobiology Institute (MBI) have developed a novel theoretical approach based on powerful transfer-matrix mathematical technique, which allows to predict how local orientational and structural fluctuations of DNA affect its large-scale behavior.
Read more.


A new class of materials

A collaboration between the theory group led by Asst/Prof Adam SHAFFIQUE and the experimental group of Prof Michael FUHRER from Monash University produced, for the first time, ultra-thin films of an exciting new class of materials known as Weyl semi-metals.
Read more.


Recyclable nanocomposites for environmental remediation

A team of scientists led by Prof CHEN Wei from the Department of Chemistry and Physics in NUS has developed multi-component nanocomposites which function as efficient visible-light photocatalysts with excellent magnetic recoverability. There is rapidly growing demand for materials with high efficiency, good reusability, and low cost to reduce pollutants from wastewater.
Read more.


A see-through metal

An experimental research team led by Asst/Prof Goki EDA from the Departments of Chemistry and Physics and the Centre for Advanced 2D Materials in NUS found that metal nanoparticles partially lose their ability to reflect light and become semi-transparent when a layer of ultra-thin semiconductor is placed in their proximity.
Read more.


The mechanical response of talin

A study is led by Assoc. Prof. Jie Yan from the Department of Physics and Mechanobiology Institute, NUS and Prof. Michael Sheetz from the Mechanobiology Institute, NUS have shown how a protein called talin senses mechanical force exerted on a cell and buffers the force through stochastic unfolding and refolding of its multiple folded domains during mechanical stretching and relaxation of talin.
Read more.


Biomimetic autonomous nanowalker breaks record of fuel efficiency

Led by Prof. Zhisong Wang, a team of graduate students and researcher fellows at NUS Physics have designed and demonstrated an autonomous DNA bipedal nanowalker that achieves a fuel efficiency of less than two fuel molecules consumed per step. This work is published in ACS NANO.
Read more.


"Butterfly" defects on 2D Materials

A team led by Prof Andrew WEE and Prof QUEK Su Ying, together with Dr HUANG Yuli from A*STAR's Institute of Materials Research and Engineering (IMRE) discovered novel defect states at grain boundaries (GBs) in a two-dimensional (2D) semiconductor.
Read more.


Unique photoresponse from 2D phosphorene-phosphorene-suboxidee

A team led by Prof Chorng Haur SOW, Prof Barbaros ÖZYILMAZ, Prof Antonio CASTRO-NETO, Dr Alexandra CARVALHO and Dr Junpeng LU from the Department of Physics and the Centre for Advanced 2D Materials in NUS devised a straightforward method to create a functional junction on a phosphorene flake, observing enhanced photoresponse from it.
Read more.


Quantum satellite device tests technology for global quantum network

Singapore-built satellite makes and measures light particles pair by pair. Team-leader Asst/Prof Alexander Ling, a Principal Investigator at the Centre for Quantum Technologies (CQT) at NUS, says "This is the first time anyone has tested this kind of quantum technology in space."
Read more.


Topological semimetal phases via periodic driving

NUS scientists have discovered Floquet topological semimetal phases in a simple dynamical model. Aa team led by Prof GONG Jiangbin has advanced this topic by showing how three-dimensional (3D) topological semimetal phases can be easily obtained and simulated using 1-dimensional (1D) dynamical systems.
Read more.


Giant photoluminescence in monolayer tungsten diselenide

A group of NUS physicists lead by Professor Andrew Wee have shown that giant photoluminescence (PL) enhancement is demonstrated by suspending the two-dimensional (2D) semiconductor WSe2 on sub-20 nanometre (nm) wide trenches in gold nanoarray substrates.
Read more.


Result smashes size record for quantum correlations

In collaboration with researchers at the University of Basel in Switzerland, CQT theorists Jean-Daniel Bancal and Professor Valerio Scarani found evidence of Bell correlations in an ultracold cloud of about 480 atoms. The research is described in the paper "Bell correlations in a Bose-Einstein condensate" published 22 April in Science.
Read more.


Team Discovers New Way of Transferring Magnetic Information

A team led by researchers from the National University of Singapore (NUS) has achieved a major breakthrough in magnetic interaction. By adding a special insulator, they make electrons "twirl" their neighbouring "dance partners" to transfer magnetic information over a longer range between two thin layers of magnetic materials.
Read more.


Surviving spins in two dimensions

A team co-led by Asst/Prof Goki EDA and Asst/Prof Shaffique ADAM, in collaboration with experimental and theoretical research groups from the Department of Physics in NUS and Yale-NUS College, has discovered the underlying spin scattering mechanisms in a 2D sheet of MoS2.
Read more.


NUS researchers find new way to control electrons

Scientists at the National University of Singapore (NUS) have demonstrated a new way of controlling electrons by confining them in a device made out of atomically thin materials, and applying external electric and magnetic fields. This research, published in the prestigious scientific journal Nature, was led by Professor Antonio Castro Neto and his research team at the Centre for Advanced 2D Materials (CA2DM).
Read more.


Experiment records extreme quantum weirdness

Professor Christian Kurtsiefer and researchers from CQT have reported the most extreme 'entanglement' between pairs of photons ever seen in the lab. The result was published 30 October in Physical Review Letters, where it is highlighted as an Editors' Suggestion.
Read more.


'Breathing physics' at the atom smasher

The NUS High Energy Physics Phenomenology Group was featured on Monday Straits Times, 16 Nov 2015: "'Breathing physics' at the atom smasher". The group is led by Prof. Oh CH and A/Prof. Phil Chan, comprising two PhD students and five MSc particle physics students.
Read more.


Scientists achieve major breakthrough in thin-film magnetism

A team of scientists (Mr Li Changjian, Asst/Prof Ariando and Professor T Venky Venkatesan) from the National University of Singapore (NUS), together with collaborators from Singapore, the Netherlands, United States and Ireland, has uncovered a new twist to the story of thin-film magnetism by growing perfectly-crystalline atomic layers of a manganite using a method known as pulsed laser deposition. Read more.


Exacting measurements on atoms do better than theory

A new publication led by Asst/Prof Manas Mukherkee and his team has been published in Physical Review A on 17 April as a Rapid Communication. The results are relevant to the search for physics beyond the Standard Model. Read more.


Dynamics of equilibrium folding and unfolding transitions of titin immunoglobulin domain under constant forces

A new JACS publication by A/Prof Yan Jie and his team report the first equilibrium single-molecule force manipulation study of the classic titin I27 immunoglobulin domain using ultra stable magnetic tweezers. Read more.


Stability and Kinetics of c-MYC Promoter G-Quadruplexes Studied by Single-Molecule Manipulation

A new publication by A/Prof Yan Jie and his team provide important insights into the stability of a broad class of promoter G4's which also play a role in transcription regulation and are potential anticancer targets. Read more.


Visualising Interstellar's black hole

If you have watched the movie Interstellar, you would have seen the images of light around the black hole Gargantua. One effect present is the "shell of fire", which refers to light rays going around a rotating black hole in a spherical orbit. Such orbits were in fact first studied in detail by Assoc. Prof. Edward Teo. A description of this effect and how it was used to produce images of Gargantua can be found in Kip Thorne's book, "The Science of Interstellar." Prof Teo's original paper can be found here.


Interconversion between three overstretched DNA structures

A new publication by A/Prof Yan Jie and his team reports systematic studies of interconversion between these overstretched DNA structures induced by changing NaCl concentration at constant force. Read more.


Advanced Material Interfaces 06/14

The collaboration work between Dr. Ariando, Prof. Venkatesan and Prof. Feng on the physics which explains the role of oxygen vacancy and polar catastrophe on the origin of the 2D electron gas at the complex oxide interfaces is highlighted on the cover of Advanced Material Interfaces. The complete article can be found here.


The Rise of Spintronics in CVD Graphene

A group of scientists at the Graphene Research Center led by Prof. Oezyilmaz have now discovered that the spin Hall effect is intrinsic to graphene synthesized on metallic surfaces by means of chemical vapour deposition.
Read more.


NUS researchers discover a new mechanism for magnetoresistance in disordered two-dimensional materials

A collaboration between researchers at Monash University (Australia), the University of Maryland (USA) and Shaffique Adam's research group at the National University of Singapore has resulted in the theoretical prediction and experimental observation of a new mechanism by which an applied magnetic field can increase the resistance in disordered graphene and other two-dimensional materials.  This work appears in the latest issue of Physical Review Letters, and was designated as an Editors' Suggestion (an honor awarded to the top 15 percent of Letters published in this prestigious journal).
Read more.


Every Electron Counts!

Using unique research facilities at free-electron laser FLASH at DESY (Germany) and Singapore Synchrotron Light Source of National University of Singapore, a team consisting of researchers from National University of Singapore (NUSNNI-Nanocore, Singapore Synchrotron Light Source, and Department of Physics), Germany (Center for Free Electron Laser, DESY, and University of Hamburg), USA (University of Illinois at Urbana-Champaign and Advanced Photon Source), Japan (University of Tokyo and AIST), reveals electronic correlations and screening mechanisms of effective Coulomb on-site repulsions in a model high-temperature superconductor cuprate, spin-ladder compound.
Read more.


Probing the physical principles of mechanosensing by cells

This research is led by Associate Prof Yan Jie and principal investigator at MBI, NUS, and Prof Rene Mege, principal investigator at the Institut Jacques Monod (IJM), University Paris Diderot & CNRS, in collaboration with colleagues from NUS and IJM. 
Read more.


Going nano with new 2D materials centre

The University has established the Centre for Advanced 2D Materials to study and develop applications for materials that are atomically thin with a S$50-million grant from the National Research Foundation (NRF). The Centre builds on the success of the Graphene Research Centre (GRC), which will have its activities folded into the new Centre. 
Read more.


New research shows unlimited heat conduction in graphene

It was reported that scientists at NUS and the Max Planck Institute for Polymer Research in Mainz have attested that the thermal conductivity of graphene diverges with the size of the samples. This discovery challenges the fundamental laws of heat conduction for extended materials. Their research and results have now been presented in the scientific journal Nature Communications. A similar report was carried in: R & D magazine.


Scientists open door to better solar cells, superconductors and hard-drives

The team of Asst/Prof Andrivo Rusydi from the National University of Singapore and Prof. Michael Rübhausen from the Hamburg Center for Free-Electron Laser Science (CFEL) have solved a long standing mystery in the physics of condensed matter. Using DESY's bright research light sources, they have opened a new door to better solar cells, novel superconductors and smaller hard-drives. 
Find out more.


Materials: Directional conductivity when under strain Tensile strain induced directional conductivity in ultra-thin manganite films

A research collaboration between Asst Prof Andrivo Rusydi and collaborators from Nanyang Technological University and Chinese Academy of Sciences, China have discovered that La0.7Sr0.3MnO3 (LSMO) ultra-thin films exhibit the ability to conduct electricity in a certain direction when it is placed under tensile strain conditions at low temperatures.
Find out more.


Two pieces of good works just published in Physcial Review Letter

(a) Experimental work (with ECE colleagues J Thong and Cheng-Wei Qiu) on "thermal cloak" published in Physical Review Letters (3 Feb 2014). This paper, together with another one from NTU, has been selected as Viewpoint in Physics "Thermal Cloaks get hot" (b) A rigorous mathematical theory has been worked out on anomalous heat diffusion. It is rare in this field as it is difficult to get a rigorous theory. S. Liu, P Hanggi, N.-B Li, J. Ren, and B Li, Anomalous heat diffusion, Physical Review Letters 112, 040601, 28 Jan 2014.


Joint graphene research to boost data storage

Faster, smaller and more durable data storage for laptops, smart phones and tablet PCs, with hard disk capacity in the region of tens of terabytes instead of the present gigabytes - these will be the potential results of a new joint venture between the Graphene Research Centre (GRC) at the NUS Faculty of Science and Fuji Electric (Malaysia) Sdn Bhd.
Read more.


Cloak made of Telflon catch eyes in web

A research team, from Zhejiang University in China, the Royal Institute of Technology in Sweden and National University of Singapore (Prof C. K. Ong) have discovered an alternative way to make an invisibility cloak that departs from other attempts to do so. Read more: 1 & 2.


Latest Nano Letters publication

Asst/Prof Adam Shaffique's publication "Direct Imaging of Charged Impurity Density in Common Graphene Substrates" was published in Nano Letters. Read more.


Unexpected Conductivity

Asst/Prof Adriando's research team work at NUS is today highlighted by Science Magazine as an Editor’s choice. Interfacing two dissimilar crystals can lead to unexpected phenomena, as best illustrated by the formation of a highly mobile metallic two-dimensional electron gas (2DEG) between two insulators, SrTiO3 (STO) and LaAlO3.
Read more.

A research breakthrough in Graphene Hybrid research

Organic Nano Device Laboratory (ONDL) has made a research breakthrough in Graphene Hybrid research that has been published in Nature Nanotechnology. They have created a first artificial graphite intercalation compound made by layer-by-layer stacking of graphene. read more.

A new revolutionary way to tailor two dimensional sheet of electrons

A research collaboration between Prof. Ariando and Prof. Venky Venkatesan at NanoCore, National University of Singapore, and collaborators from Japan, Sweden, China and The Netherlands have discovered a new revolutionary way to tailor two dimensional sheet of electrons along specific crystallographic orientation at the interface of insulating oxide systems. read more.

How Graphene and Friends Could Harness the Sun's Energy Hitting Walls

It was reported that a team of researchers from University of Manchester and Graphene Research Centre at NUS have discovered that combining wonder material graphene with other stunning one-atom thick materials could create the next generation of solar cells and optoelectronic devices. read more.
Similar reports in PhysOrgNanowerkMancunian MattersScience Newsline and Bio-medicine.


Review paper published in highest-ranked journal (I.F.:40.197) "Chemical Reviews"

Dr. M.V. Reddy from Advanced Batteries lab published their Review paper on anode materials for Li-ion batteries. For the 1st time Asian University published Review paper in Chemical Reviews in the area of Lithium-ion batteries anodes.


Controllable unzipping for intramolecular junctions of graphene nanoribbons and single-walled carbon nanotubes

Graphene is often regarded as one of the most promising candidates for future nanoelectronics. As an indispensable component in graphene-based electronics, the formation of junctions with other materials not only provides utility functions and reliable connexions, but can also improve or alter the properties of pristine graphene, opening up possibilities for new applications.


Functionalized graphene converts charge currents into spin currents

A research team led by Asst Prof Barbaros Özyilmaz from the Department of Physics and theGraphene Research Center at the National University of Singapore took advantage of graphene’s unique mechanical properties to artificially increase the intrinsic spin-orbit coupling of graphene. The paper is now available online.


NUS researchers revealed three distinct structural reorganizations of DNA

In a series of recent studies led by Jie Yan (Associate Professor of Department of Physics, Principal Investigator of Mechanobiology Institute (MBI), Centre of Bio-imaging Sciences (CBIS), and Singapore-MIT Alliance for Research and Technology (SMART)) has demonstrated that all the three transitions exist, and which ones occur depends on experimental conditions. read more


Secure communication technology can conquer lack of trust

It was reported that Professor Christian Kurtsiefer and Assistant Professor Stephanie Wehner of the Centre for Quantum Technologies at NUS have used the quantum properties of light to perform the world's first demonstration of a 'secure bit commitment' technology. The demonstration is a proof-of-principle that points towards a possible quantum technology for secure communication in the future. Similar reports were carried in: Phys Org & Science Newsline


NUS scientists make a significant breakthrough in plastic solar cells

In a report carried by Nature Communications last week (doi: 10.1038/ncomms2211: (http://www.nature.com/ncomms/journal/v3/n12/full/ncomms2211.html), a team of scientists from the Departments of Physics and Chemistry of NUS, together with the Cavendish Laboratory, University of Cambridge, announced a breakthrough in the morphology control and performance of plastic solar cells. Part of the work was also carried out at the Solar Energy Research Institute of Singapore (SERIS), owned by NUS. 


NUS physicists invented light-powered nanowalkers free of chemical wastes

The group of A/P Zhisong Wang at NUS Physics, in collaboration with colleagues A/P Johan van der Maarel and Asst/P Ruchuan Liu, have made and demonstrated a bipedal nanowalker that mimics biological counterparts in design but draws energy from light. This work appears in Physical Review Letters with a news highlight.


Suzi's SEM image of her mesocrystals selected for coverpage of NanoToday!

Suzi, a Research Fellow from the Nanomaterials Research Laboratory, submitted SEM image of her mesocrystals for NanoToday coverpage competition and her work was selected! It has now officially appeared as the coverpage image of the latest issue of NanoToday.


Quantum non-locality based on finite-speed causal influences leads to superluminal signalling

The experimental violation of Bell inequalities using space-like separated measurements precludes the explanation of quantum correlations through causal influences propagating at subluminal speed.

Supplemental information

Anomalous heat conduction and anomalous diffusion in low dimensional nanoscale systems

Heat conduction is an important energy transport process in nature. Phonon is the major energy carrier for heat in semiconductors and dielectric materials. In analogy to Ohm's law of electrical conduction, Fourier's law is the fundamental law of heat conduction in solids.


Does noise improve a bird's spin-based compass?

According to the "radical pair" model, some migratory birds exploit the quantum phenomenon of electron spin to navigate using the Earth's magnetic field. This idea has now been bolstered by a new study from physicists in Singapore, who have shown that the spin-based process and the dynamics of a proposed "compass" molecule take place over similar timescales. 


Quantized Adiabatic Transport In Momentum Space

Though topological aspects of energy bands are known to play a key role in quantum transport in solid-state systems, the implications of Floquet band topology for transport in momentum space (i.e., acceleration) have not been explored so far. 


Higher order oligomerization is required for H-NS family member MvaT to form gene-silencing nucleoprotein filament

MvaT from Pseudomonas aeruginosa is a member of the histone-like nucleoid structuring protein (H-NS) family of nucleoid-associated proteins widely spread among Gram-negative bacteria that functions to repress the expression of many genes.


Nucleoprotein filament formation is the structural basis for bacterial protein H-NS gene silencing

H-NS is an abundant nucleoid-associated protein in bacteria that globally silences genes, including horizontally-acquired genes related to pathogenesis.


Fluoropolymer Drops Graphene's Resistance

It was reported that Assistant Professor Özyilmaz Barbaros from the Department of Physics at the NUS Faculty of Science and researchers from Sungkyunkwan University in Suwon, South Korea worked together to develop a simple, more permanent strategy for boosting graphene's conductance.



Unveiling the Mystery of DNA overstretching transitions

When subjected to force at about 65 picoNewtons, DNA undergoes a perplexing structural transition. Referred to as overstretching, this transition abruptly extends the contour length of B-DNA around 1.7 times. Conflicting experimental findings have led to uncertainty about whether this overstretching produces a single-stranded DNA or S-DNA, a novel double-stranded DNA.



Quantum Information Motion Control Is Now Improved 

It was reported that a team of physicists from the Centre for Computational Science and Engineering of the NUS Faculty of Science and China’s Zhejiang University have devised a new method for handling the effect of the interplay between vibrations and electrons on electronic transport. The study could have implications for quantum computers due to improvements in the transport of discrete amounts of information, known as qubits, that are encoded in electrons. It was also mentioned that their paper is about to be published in The European Physical Journal B.

The research work has been highlighted  by Science Daily and PhysOrg



Novel Metal Centered Oxalato Phosphate Open Framework 4 V Cathode Materials for Lithium Ion Batteries

Angew. Chemie Int. Ed. 51(2012)5866-5870 (I.F.: 12.73)
Researchers from Dept.s of Chemistry (Prof. J. J. Vittal) and Physics (Dr. M .V. Reddy, Prof. B .V R.  Chowdari) for the first time synthesized novel metal-organic phosphate open framework materials M2[(VO)2(HPO4)(C2O4)] (M= K, Na, Li,K)  and demonstrated  as a interesting hybrid cathode materials for Lithium Ion batteries.



Prof Gong's research collaboration with China researchers 
1. Long-Lasting Exponential Spreading in Periodically Driven Quantum Systems
Jiao Wang, Italo Guarneri, Giulio Casati, and Jiangbin Gong
Phys. Rev. Lett. 107, 234104 (2011) – Published November 30, 2011

2. Quantum Hyperdiffusion in One-Dimensional Tight-Binding Lattices
Zhenjun Zhang, Peiqing Tong, Jiangbin Gong, and Baowen Li
Phys. Rev. Lett. 108, 070603 (2012) – Published February 15, 2012

3. Preferred States of Decoherence under Intermediate System-Environment Coupling
Wen-ge Wang, Lewei He, and Jiangbin Gong
Phys. Rev. Lett. 108, 070403 (2012) – Published February 17, 2012

New Theory Explains How Objective Reality Emerges from the Strange Underlying Quantum World 

Quantum theory is one of the most profound discoveries of humanity. In my view, it's on a par with Cuban cigars and single malt whiskey. The theory has been hugely successful in showing us the inner workings of the universe.



Gene silencing H-NS paralogue StpA forms a rigid protein filament along DNA that blocks DNA accessibility 

Bacterial nucleoid associated proteins (NAPs) are involved in genomic DNA packaging and global gene regulation in bacteria cells. One of the widely-studied NAPs in E.coli is H-NS which is involved in global gene silencing.



How a quintessential quantum test was fooled 

When it comes to pitting quantum theory against classical notions of the world, there's one experiment that physicists say can make a clear distinction: a test of Bell's inequalities. But in newly-published work, CQT researchers and their collaborators from Norway describe how they faked quantum results using classical physics in such a test, reminding scientists to be cautious about the assumptions in their experiments.



Real time in-situ neutron diffraction studies on lithium-ion batteries 

Researchers from ANSTO, Australia (Neeraj Sharma etal.), National University of Singapore (M V Reddy etal.) and University of Wollongong performed a successful in-situ neutron diffraction experiment on a mock lithium-ion battery while it was charging and discharging to illustrate how the crystal-structure of a cathode material changes.




Photonics: Graphene's two-photon shuffle 

Light absorption isn’t always linear, however. In some cases, two photons combine together to initiate the absorption process — a phenomenon that offers unique advantages and which is used in a variety of technological applications from microfabrication to optical data storage.  




Moment of magnetism 

Asst/Prof Ariando's work on electronic phase separation has been highlighted in the News and Views of the Nature Physics by Andrew Millis. He has been invited for a talk at the APS March meeting 2012 on this topic.




Graphene gives protection from intense laser pulses 

21 Aug 2011. Scientists at the National University of Singapore (NUS) , DSO National Laboratories and University of Cambridge have jointly announced a new world record in broadband non-linear optical absorption behavior using single-sheet graphene dispersions in a variety of heavy-atom solvents and film matrices

(G.K. Lim et al, Nature Photonics(2011):doi:10.1038/nphoton.2011.177).




Simulation of Chemical Isomerization Reaction Dynamics on a NMR Quantum Simulator

Quantum simulation can beat current classical computers with minimally a few tens of qubits. Here we report an experimental demonstration that a small nuclear-magnetic-resonance quantum simulator is already able to simulate the dynamics of a prototype laser-driven isomerization reaction using engineered quantum control pulses.

Supplemental information




Observation of Long Spin Relaxation Times in Bilayer Graphene at Room Temperature 

We report on the first systematic study of spin transport in bilayer graphene (BLG) as a function of mobility, minimum conductivity, charge density and temperature.




Graphene used in biomedical applications can control the fate of stem cells 

It is widely believed that stem cell therapies have the potential to revolutionize the treatment of human diseases. The range of potentially ground-breaking therapies based on stem cells ranges from combating Alzheimer's Disease to regenerative medicine.




Evidence for subwavelength imaging with positive refraction 

The resolution of lenses is normally limited by the wave nature of light. Imaging with perfect resolution was believed to rely on negative refraction, but here we present experimental evidence for subwavelength imaging with positive refraction.

Supplemental materials are available at

1. To invisibility and beyond
2. The laird of physics
3. The battle to find Maxwell's perfect image




Laser irradiation probes photocurrent in Nb2O5 nanowires 

Global and local measurement comparison gives better understanding of nanowire photoconductivity.




Data storage: Carbon-ferroelectric memor

A fundamental component of a field-effect transistor (FET) is the gate dielectric, which determines the number of charge carriers—electrons or electron vacancies—that can be injected into the active channel of the device.




Electronic phase separation at the LaAlO3/SrTiO3 interface

Almost a decade ago, it was shown that at the interface of two oxide insulators (LaAlO3 and SrTiO3) a 2 dimensional electron gas can form with desirable electronic properties making this a metallic interface. In this Nature Communication article, Ariando and co-workers (from NUSNNI-Nanocore, Department of Physics, ECE and MSE) show that this metallic interface when prepared under suitable conditions of oxygen pressure can become active, simultaneously exhibiting a number of interesting magnetic properties along with the metallic property of the electron gas.




Transition dynamics and selection of the distinct S-DNA and strand unpeeling modes of double helix overstretching

The mechanism of DNA overstretching has been a mystery for 15 years. Recently a group of scientists from National University of Singapore and Northwestern University has shown that there exist two distinct pathways for the DNA overstretching transition near 65 pN: ‘unpeeling’ of one strand from the other, and a “B-to-S” transition from B-DNA to an elongated double-stranded ‘S-DNA’ form (Fu et al., Nucleic Acids Research 2011: 38, 5594-5600). More recently, the same group of authors has found answers to basic questions concerning the dynamics of these transitions, relative stability of the two competing overstretched states, the biophysical properties of S-DNA, and whether the “B-to-S” transition requires nicks and free DNA ends. In addition to solving the mystery of DNA overstretching transition, these results have provided the most complete understanding of the response of DNA to large tension.




Supramolecular Materials

Supramolecular materials containing three-dimensional fiber network are designed and constructed in the micro-/nanometer scale to deliver different benefis for applications in many fields, such as drug delivery, tissue engineering, nanocrystallite synthesis, etc.


Roll-to-roll production of 30-inch graphene films for transparent electrodes

The efforts to make transparent conducting films from graphene have been hampered by the lack of efficient methods for the synthesis, transfer and doping of graphene at the scale and quality required for applications. Here, we report the roll-to-roll production and wet-chemical doping of predominantly monolayer 30-inch graphene films grown by chemical vapour deposition onto flexible copper substrates.




Two distinct overstretched DNA states

The DNA double helix undergoes an ‘overstretching’ transition in a narrow force range near 65 pN. We show that overstretching in fact involves two distinct types of double-helix reorganization: slow hysteretic ‘unpeeling’ of one strand off the other; and a fast, non-hysteretic transition to an elongated double-stranded form.

Supplemental information




Noise Bridges Dynamical Correlation and Topology in Coupled Oscillator Networks

We study the relationship between dynamical properties and interaction patterns in complex oscillator networks in the presence of noise.




Berry-Phase-Induced Heat Pumping and Its Impact on the Fluctuation Theorem

Applying adiabatic, cyclic two-parameter modulations we investigate quantum heat transfer across an anharmonic molecular junction contacted with two heat baths.

Supplemental information

Research Highlights




Semiconductors: Plastic electronics

Organic, carbon-based and soft materials crosslinking compounds help to build polymer electronic devices faster.




A divalent switch drives H-NS/DNA-binding conformations between stiffening and bridging modes

Heat-stable nucleoid structuring protein (H-NS) is an abundant prokaryotic protein that plays important roles in organizing chromosomal DNA and gene silencing. 

Supplemental material is available at http://www.genesdev.org




Simultaneous phase and size control of upconversion nanocrystals through lanthanide doping

Singapore scientists from NUS, the Agency for Science, Technology and Research (A*STAR), NTU and King Abdullah University of Science and Technology (KAUST) have discovered a new synthetic strategy for controlling the properties of ultra-small luminescent nanocrystals. Their findings have been published in the prestigious
 Nature journal on 25 February 2010




Capillarity-Assisted Assembly of Carbon Nanotube Microstructures with Organized Initiations

ACS Nano, 2010, 4 (2), pp 1067–1075
DOI: 10.1021/nn9012109
Publication Date (Web): January 7, 2010

In this work, detailed studies of three different capillary-assisted techniques for the formations of large-scale multiwalled carbon-nanotube (MWNT)-based microstructures were presented. These new insights and techniques presented could further encourage the use of self-organized MWNT structures with initiation as a flexible and viable route for the implementations of carbon-nanotube-based electronic devices.




Universal dynamical decoupling: Two-qubit states and beyond

Uhrig’s dynamical decoupling pulse sequence has emerged as a universal and highly promising approach to decoherence suppression. So far, both the theoretical and experimental studies have examined single-qubit decoherence only. This work extends Uhrig’s universal dynamical decoupling from one-qubit to two-qubit systems and even to general multilevel quantum systems.




Polymer semiconductors become sophisticated

News Release (31 Dec 2009, Singapore):  NUS scientists from the departments of physics and chemistry, in collaboration with Cambridge scientists, have announced their success in creating high-quality heterostructures that make polymer organic semiconductors more functional and energy-efficient. The report was carried online by Nature Materials (http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat2594.html), Heterostructures are interfaces of two or more materials with carefully selected energy-level, bandgap or refractive-index differences that enable charge-carriers, excitons and photons to be manipulated within layers as thin as a few nanometers.   


Tunable Two-Dimensional Binary Molecular Networks

A novel approach to constructing tunable and robust 2D binary molecular nanostructures on an inert graphite surface is presented. The guest molecules are embedded into a host molecular matrix and constrained via the formation of multiple intermolecular hydrogen bonds.


A Rotational DNA Nanomotor Driven by an Externally Controlled Electric Field

Continuous rotation of DNA around its phosphate backbone is achieved with a simple nanomotor, which is driven by an electric field oscillated between four orientations (see image). The motor consists of a DNA rotor and a partially single-stranded DNA axle held between a surface and a magnetic bead. Rotation is caused by realignment of the rotor DNA with the oscillated electric field.


A new physical principle behind quantum physics

Tomasz Paterek, Dagomir Kaszliskowski, Valerio Scarani and Andreas Winter from CQT, together with co-workers of the University of Gdansk (Poland), propose a new physical principle called "information causality" in a paper published in Nature. If this principle is enforced, the number of theories that can describe our world is drastically reduced. This might explain why no phenomenon has ever been observed that would go beyond quantum physics. 




Macromolecular crowding induced elongation and compaction of single DNA molecules confined in a nanochannel

The effect of dextran nanoparticles on the conformation and compaction of single DNA molecules confined in a nanochannel was investigated with fluorescence microscopy. It was observed that the DNA molecules elongate and eventually condense into a compact form with increasing volume fraction of the crowding agent.


The security of practical quantum key distribution

Quantum key distribution (QKD) is the first quantum information task to reach the level of mature technology, already fit for commercialization. It aims at the creation of a secret key between authorized partners connected by a quantum channel and a classical authenticated channel.
DOI: 10.1103/RevModPhys.81.1301




Doping graphene: Molecular tuning

An article “Tuning the Electronic Structure of Graphene by an Organic Molecule” that originally appeared in J. Phys. Chem. B  which Professor Feng Yuan Ping and Dr Lu Yunhaocollaborated with researchers from Zhejiang University has been highlighted in the Sept issue of NPG Asia Materials.  
Professor Feng and colleagues in Singapore and China report that the adsorption of organic molecules onto graphene could allow the electronic properties of graphene to be controlled and tuned. Their first-principles calculations show that a charge-transfer complex is created with the electron–acceptor molecule tetracyanoethylene (TCNE), allowing the electronic properties of graphene to be tuned by adjusting the coverage of adsorbed molecules.




Stretching Single Talin Rod Molecules Activates Vinculin Binding

"To solve the mystery of how a mechanical stimulus is translated into a chemical response in biological systems, Asst. Prof. Liu Ruchuan has collaborated with researchers at Columbia University to examine vinculin binding of talin rods under mechanical forces by single-molecule techniques, and proved a hypothesis of mechano-activation of talin for vinculin recruitment. As talin and vinculin play important roles between focal adhesion and the cytoskeleton, such a mechanism as proposed in their recent Science paper [Science 323, p638-641] may exist more generally in biological systems as a mechanism for force transduction."


A viewpoint on: Atom interferometry tests of local Lorentz invariance in gravity and electrodynamics

An article which Asst/Prof Chung Keng Yeow collaborated with researchers from UC Berkeley, Stanford University and Bremen University has been highlighted in the July issue of Physical Review D ( http://prd.aps.org/ ). It was also selected for a viewpoint in Physics, an online publication of APS started last year that “highlights exceptional papers from the Physical Review journals” (quoted from the website). 

Measuring quantum interference of atomic matter waves may help detect experimental signatures of a fundamental theory of physics. [Viewpoint on Phys. Rev. D 80, 016002 (2009)]. Seehttp://physics.aps.org/articles/v2/58




An omnidirectional retroreflector based on the transmutation of dielectric singularities
Cyclists and runners may one day have perfect reflecting devices to keep them safe in night-time traffic. Scientists here, working with theortical physicists from Scotland and the Czeh Republic, have married a theory of bending light with practical engineering. The team of Prof Ong Chong Kim and his collaborator Dr Ma Yun-Gui of the Temasek Laboratories and theoreticians aboard have designed a retroreflector which have potential use from road safety to radar target tracking.Their paper was published online 28 June 2009 in materials-science journal Nature Materials and inStraits Times, 4 July 2009 titled "Bright idea for bend theory".


Magnonic Spin-offs

Magnonic crystals, a lesser known analog of photonic crystals, form the basis of magnonics. It is an emerging field which aims to control the generation and propagation of information-carrying spin waves by means analogous to the control of light in photonic crystals. The Laser Brillouin Group has designed a nanostructured magnonic crystal comprising two different magnetic materials and mapped out its dispersion relations. Its frequency bandgaps exhibit magnetic-field tunability, an important property which could find applications in magnonic devices. This work published in Appl. Phys. Lett. Vol. 94 (2009)has been highlighted in Nature Materials Vol. 8 May (2009) as an article entitled Magnonic Spin-offs.


A Step Toward Superfast Carbon Memory - Graphene could make computer hard drives denser and speedier

Graphene memory can have significant advantages over today's magnetic memory. Bits can be read 30 times faster because electrons move through graphene quickly. With graphene, bits can also shrink to 10 nanometers or even smaller thus making the memory denser. In the Technology Review published by MIT on Wednesday, April 01, 2009, the work of Dr Özyilmaz Barbarosand histeam onferroelectric RAM was publicized in the article titled “A Step Toward Superfast Carbon Memory - Graphene could make computer hard drives denser and speedier” by Prachi Patel..



Graphene gets ready for the big time

Work on graphene heated up quickly since five years ago as researchers realized that the material’s two-dimensionality caused it to show unusual quantum behaviours. In the recent American Physical Society meeting in Pittsburgh, Pennsylvania, physicist were deliberating on how to bring this laboratory curiosity to the commercial. In the article of the meeting published on Natures News, a STM grapheme image due to the recent work of Prof Andrew Wee and Dr Chen Wei of Physics department (A. WEE, NATL UNIV. SINGAPORE/H. HUANG ET AL. ACS NANO 2, 2513–2518 (2008) 390 Vol 458|26 March 2009) was cited in the report.


Having fun with dumpling skin: material physics made alive in the kitchen

Phys. Educ. 44 180-183   doi: 10.1088/0031-9120/44/2/010 

Abstract. We report a school project which equips students with both theoretical and practical knowledge in material physics. We construct dumpling skins from a mixture of flour and water. A series of experiments is then conducted to quantify the toughness, hardness, and tensile strength of the skins, and how they are affected by adding other materials into the original material to form composite materials.

Print publication: Issue 2 (March 2009) 
Received 25 November 2008, in final form 11 December 2008



Our heat memory work has been reported by public news media in the following articles:

1. Physics World . "Memory devices could store data by using heat"
http://physicsworld.com/cws/article/news/35579

2. PHYORG. "Scientists Propose Thermal Memory to Store Data"
http://www.physorg.com/news150556658.html

3. Science News Magazine. "Hot New Memory"
http://www.sciencenews.org/view/generic/id/39403/title/Hot_new_memory

4. New Scientists. "Thermal computing is heating up"
http://www.newscientist.com/article/dn16512-thermal-computing-is-heating-
up.html?DCMP=OTC-rss&nsref=online-news

 


A New Data Acquisition and Imaging System for Nuclear Microscopy Based on NI FPGA Technology

The introduction of the FPGA cards by NI has made it possible for the first time to develop reconfigurable custom data acquisition hardware easily with LabVIEW. Data acquisition issues such as precise timing for scanning and operating system latencies can now be easily overcome using this new technology because the data acquisition software is embedded in the FPGA chip on the card.




Graphene solution

Graphene—carbon atoms in a single honeycomb sheet—is proving to be a remarkable material because of its excellent electron transport properties and potential applications. Reproducible ways of synthesizing this material are still under development, however, and a simple means of depositing films is still elusive.




Dynamics of Matter-Wave Solitons in a Ratchet Potential

We study the dynamics of bright solitons formed in a Bose-Einstein condensate with attractive atomic interactions perturbed by a weak bichromatic optical lattice potential.


Low-Temperature Scanning Tunneling Microscopy Investigation of Epitaxial Growth of F16CuPc Thin Films on Ag(111)

In-situ low-temperature scanning tunneling microscopy (LT-STM) used to systematically investigate the epitaxial growth behaviors of copper hexadecafluorophthalocyanine (F16CuPc) on Ag(111) from one monolayer to a few layers is featured on the front cover of the Journal of Physical Chemistry, Vol. 112, No, 8, September 25, 2008.


Structure-Mechanical Properties of Individual Cobalt Oxide Nanowires

We present a combinatory approach to address the correlation between mechanical properties of individual nanowires (NWs) with their characteristic size, microstructure and chemical composition. The same individual NWs can be studied repeatedly after different treatments.




Thermal memory: a storage of phononic information

In this Letter we demonstrate via numerical simulation that thermal (phononic) information stored in the memory can be retained for a long time without being lost and more importantly can be read out without being destroyed. The work is also highlighted in physicsworld.com on August 29, 2008.



Aligned CNT as Nanosieve for Quantum Dots

In recent years, great progress has been made in the synthesis and application studies of hybrid nanomaterial systems involving carbon nanotubes (CNTs). Efforts involve the alteration of physical properties of CNTs via the use of organic, inorganic, and biological species to produce functionalized CNTs for further applications. The work is highlighted in Nanowerk.com on June 27, 2008.



Borane leads the way to alternative fuels

New routes to hydrogen storage materials, which could offer alternative fuel for cars, have been developed by two teams of scientists in the US and Singapore.




Quantum cryptography with finite resources

Quantum cryptography is the first quantum information task to reach the level of mature technology, already fit for commercialization. It aims at the creation of a secret key between authorized partners connected by a quantum channel and a classical authenticated channel, whence the proper name of Quantum Key Distribution (QKD).




Self-assembled organic donor/acceptor nanojunction arrays

We have fabricated well-ordered organic donor/acceptor nanojunction arrays comprising p-sexiphenyl (6P) and C60 via self-assembly of C60 on the molecular nanotemplate of 6P nanostripes on Ag(111). This paper has made the cover of Applied Physics Letters on May 2008 issue. It is also highlighted by the Nature Nanotechnology, Vol. 3 July 2008, page 375.



Electrifying hot silicon nanowires

New simulations predict that doping silicon nanowires with heavier silicon isotopes can dramatically lower their thermal conductivity-an important step towards the realization of high efficiency thermoelectric nanowire devices.




Molecular Dynamics Simulation of Multivalent-Ion Mediated Attraction between DNA Molecules

All atom molecular dynamics simulations with explicit water were done to study the interaction between two parallel double-stranded DNA molecules in the presence of the multivalent counterions putrescine (2+), spermidine (3+), spermine (4+) and cobalt hexamine (3+).




Controlling the Ratchet Effect for Cold Atoms 

Low-order quantum resonances manifested by directed currents have been realized with cold atoms.




Thermal Transistors and logic gates: Phononics gets hot

Researchers have succeeded in building diodes that manipulate heat, which paves the way for thermal transistors and logic.




Experimental Falsification of Leggett's Nonlocal Variable Model 

Bell's theorem guarantees that no model based on local variables can reproduce quantum correlations. Also, some models based on nonlocal variables, if subject to apparently “reasonable” constraints, may fail to reproduce quantum physics.




High-capacity hydrogen storage in lithium and sodium amidoboranes

The safe and efficient storage of hydrogen is widely recognized as one of the key technological challenges in the transition towards a hydrogen-based energy economy.




Thermal logic gates: Computation with phonons

Logic gates are basic digital elements for computers. We build up thermal logic gates that can perform similar operations as their electronic counterparts.




The ratchet effect and transport islands in chaotic sea

Study of directed transport in a classical deterministic dissipative system. The generic case of mixed phase space and show that large ratchet currents can be generated thanks to the presence, in the Hamiltonian limit, of transporting stability islands embedded in the chaotic sea.




Configuration dependent critical nuclei in the self assembly of magic clusters

Evidence for the formation of various 2-D structures possessing different numbers of Co–Si magic clusters (size 10.0 ± 0.5 ), configurations and lifetimes are studied in real time on a Si(111)-(7 × 7) surface at elevated temperature in the STM.




Controlled insulator-to-metal transformation in printable polymer composites with nanometal clusters

The synthesis of highly water and alcohol soluble gold clusters that can be homogeneoulsy dispersed into poly(3,4-ethylenedioxythiophene) to give a material with annealed d.c. conductivity tunable between 10^-4 and 10^5S cm-1.




 

 

 

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