HIGHLIGHTS Archives |

Tailoring a large area pseudo-magnetic field in graphene by placing it on a crystal with different symmetry

CategoryHIGHLIGHTSPosted on10/08/201810/08/2018

Figure 1: (Left) The lattice mismatch between the monolayer graphene (black) on multilayer black phosphorous (blue) generates PMF on the graphene layer. (Right) The spatial distribution and intensity of the PMF can be tailored by changing the rotation angle between the graphene and black phosphorous. (Image: NUS)

NUS researchers have discovered a simple and effective method to produce a large area pseudo-magnetic field (PMF) on graphene, and demonstrated how it can be tuned with desired spatial distribution and intensity for data storage and logic applications (“Tailoring sample-wide pseudo-magnetic fields on a graphene-black phosphorus heterostructure“).

The field of electronics focuses on how to control and exploit the properties of electrons. To study or modify the properties of these electrons at the quantum regime, a magnetic field has to be applied. Continue Reading

Scientists solve 65-year-old open theoretical problem on electron interactions

CategoryHIGHLIGHTSPosted on10/08/201810/08/2018

New discovery published in Science explains what happens during the phase transition in Dirac materials, paving the way for engineering advanced electronics that perform significantly faster

Shaffique Adam, who holds joint appointments in Centre for Advanced 2D Materials and the Department of Physics at the National University of Singapore, is the lead author for a recent work that describes a model for electron interaction in Dirac materials, a class of materials that includes graphene and topological insulators, solving a 65-year-old open theoretical problem in the process. The discovery will help scientists better understand electron interaction in new materials, paving the way for developing advanced electronics such as faster processors. The work was published in the peer-reviewed academic journal Science on 10 August 2018.

Graphene enters the stratosphere

CategoryHIGHLIGHTSPosted on08/08/201810/08/2018

Graphene’s usefulness on Earth has already been established in the last decade. It is now an opportune time to expand its prospects for use in space applications – an area touted as being the most challenging to modern technology – and shift the paradigm of materials science. Space is the final frontier for graphene research, and I believe this is the first time that graphene has entered the stratosphere,”
– Professor Antonio Castro Neto

On 30 June 2018, the spacecraft was launched over the Mojave Desert in the United States. CA2DM has teamed up with US-based aerospace company Boreal Space to test the properties of graphene after it has been launched into the stratosphere. The results could provide insights into how graphene could be used for space and satellite technologies.

CA2DM Director among world’s most impactful researchers 2017

CategoryHIGHLIGHTSPosted on20/11/201720/11/2017

Thirteen NUS researchers have been named among the world’s most highly cited, based on Clarivate Analytics’ 2017 Highly Cited Researchers report released on 15 November. This is also the fourth consecutive year NUS has fielded the most number of highly cited researchers among research institutions in Singapore.

Clarivate Analytics’ citation analysis has shown that these researchers consistently win peer approval from around the globe for their remarkable research in their respective fields, including chemistry, computer science, engineering, materials science, mathematics, physics, psychology and social sciences. This was determined by the extent their papers have supported, influenced, inspired and challenged other researchers internationally.

Professor Ho Teck Hua, NUS Deputy President (Research & Technology) and Tan Chin Tuan Centennial Professor, said that the University is proud of the achievements of the 13 NUS researchers that have helped raise Singapore’s global standing in research excellence, adding that it is a strong recognition of the University’s broad base of research capabilities.

Research team led by NUS scientists breaks new ground in memory technology

CategoryHIGHLIGHTSPosted on24/10/201724/10/2017

Novel organic thin film significantly outperforms existing flash memory devices

An international research team led by scientists from the National University of Singapore (NUS) pioneered the development of a novel thin, organic film that supports a million more times read-write cycles and consumes 1,000 times less power than commercial flash memories.

The novel organic film can store and process data for 1 trillion cycles and has the potential to be made even smaller than its current size of 60 square nanometers, with potential to be sub-25 square nanometres.

“The novel properties of our invention opens up a new field in the design and development of flexible and lightweight devices. Our work shifts the paradigm on how the industry has traditionally viewed organic electronics, and expands the application of such technologies into new territories,” said Professor T Venky Venkatesan, Director of NUS Nanoscience and Nanotechnology Institute (NUSNNI), the overall coordinator for this groundbreaking project.

The invention of this novel memory device was first reported online in the journal Nature Materials on 23 October 2017.
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Novel “converter” invented by NUS scientists heralds breakthrough in ultra-fast data processing at nanoscale

CategoryHIGHLIGHTSPosted on20/10/201720/10/2017

Invention bagged four patents and could potentially make microprocessor chips work 1,000 times faster

Advancement in nanoelectronics, which is the use of nanotechnology in electronic components, has been fueled by the ever-increasing need to shrink the size of electronic devices in a bid to produce smaller, faster and smarter gadgets such as computers, memory storage devices, displays and medical diagnostic tools.

While most advanced electronic devices are powered by photonics – which involves the use of photons to transmit information – photonic elements are usually large in size and this greatly limits their use in many advanced nanoelectronics systems.

Plasmons, which are waves of electrons that move along the surface of a metal after it is struck by photons, holds great promise for disruptive technologies in nanoelectronics. They are comparable to photons in terms of speed (they also travel with the speed of light), and they are much smaller. This unique property of plasmons makes them ideal for integration with nanoelectronics.

Space, the final frontier for Graphene and 2D Materials

CategoryHIGHLIGHTSPosted on05/10/201717/07/2018

Several years ago Prof. Castro Neto predicted the importance of graphene and other 2D materials on space technology and exploration: “In the space business weight is a big issue from the financial and physical perspectives. The heavier the payload the higher the cost of launching rockets and accelerating them into higher speeds. Graphene and 2D materials are the lightest functional materials in the universe and hence are perfect in terms of mass density”, says Prof. Castro Neto, “and, moreover, in the absence of air and water, 2D materials never corrode and can last indefinitely.” Prof. Castro Neto goes further “In deep space the temperatures are so low that some 2D materials superconduct reducing the energy cost of operation to a perfect zero.”

Prof Castro Neto’s dreams of making graphene a big player in the space race are becoming reality. In collaboration with Boreal Space, a US based satellite launcher, CA2DM is soon launching the first graphene devices into orbit opening a new chapter in space exploration for 2D materials.

Find out more of this exciting news here.

Monochalcogenides enrich library of 2D crystals

CategoryHIGHLIGHTSPosted on10/07/201703/10/2017

The field of two-dimensional materials is possibly one of the fastest expanding fields in material science and condensed matter research worldwide. The interest on this class of materials was boosted by the fast development of ever more efficient methods to synthesize them at atomically thin level.

Within the ever-growing library of 2D crystals, layered group-IV monochalcogenides (MC) have become an increasingly important group of materials. In particular, the binary IV-VI compounds SnS, SnSe, GeS, and GeSe, which form a subgroup with orthorhombic structure. SnS can be found in nature: its orthorhombic α phase, also known as herzenbergite, is a naturally occurring (nontoxic) mineral with an optical band gap of ≈ 1.3 eV, in the range of optimal values for solar cells (1.1 to 1.5 eV). Such properties boosted experimental and theoretical research on SnS in recent years.

Gate-Tunable Giant Stark Effect in Few-Layer Black Phosphorus

CategoryHIGHLIGHTSPosted on07/07/201703/10/2017

Two-dimensional black phosphorus has sparked enormous research interest due to its high carrier mobility, layer-dependent direct bandgap and outstanding in-plane anisotropic property. It is one of the few 2D materials where it is possible to tune the bandgap over a wide energy range from the visible to the IR spectrum.

When a few atomic layers of BP are exposed to an electric field, a physical phenomenon known as the Stark effect is observed. In atomic spectra, the Stark effect is the shifting and splitting of atomic energy levels under the influence of an externally applied electric field. Similarly, this Stark effect causes the conduction and valence band to shift towards each other, resulting in the reduction of the bandgap of few-layer BP.

2D materials for all-optical photonic devices

CategoryHIGHLIGHTSPosted on25/10/201603/10/2017

There is an ultimate limit for electronic miniaturization imposed by electron-electron interactions and by the Pauli exclusion principle that forbids two electrons to occupy the same quantum state. This will eventually prevent the development of denser circuitry, as well as of multiplexed or parallel schemes using electrons as information carrier units. Photons, however, can share a same logical gate, without interacting among one another, unless mediated by the supporting material and its nonlinear optical properties. This suggests that, in the near future, technology based on all-optical photonic devices will partially take over electronics and, possibly, extend classical computing in use today to include new quantum protocols and techniques. In this photon controlling photon type of devices, materials that provide efficient nonlinear optical interaction will indubitably play a central role.