Our research group forms the interface between fundamental condensed matter physics and applied solid-state device engineering. Our research works are centering around the following themes.
Physics and design of high-efficiency electrical contacts and low-power beyond CMOS computing electronics
The advancements of 2D materials, van der Waals heterostructures and topological semimetals have led to a new paradigm shift in the design of next-generation solid-state device technology. Using quantum transport theory and first-principle DFT simulation, we study the electronic and transport properties of these revolutionary materials and how such properties can be mapped onto the design of low-power computing devices with novel functionalities, such as valleytronics, spintronics and reversible computing as well as electrical contact heterostructures. Our group has recently reported the pioneering studies of electrical contacts and heterostructures based on MoSi2N4, WSi2N4 and the broader MA2Z4 monolayer family.
arXiv:2012.07465 (2021). To appear in npj 2D Materials and Applications.
Appl. Phys. Lett. 118, 013106 (2021). ESI Highly-Cited Article. Selected as "Editor's Pick" and "Most Read" article
Appl. Phys. Lett. 118, 113102 (2021). Selected as "Featured Articles" and highlighted in "Scilight".
Phys. Rev. B 96, 245410 (2017). Selected as PRB Kaleidoscope. Included in the Beyond CMOS Chapter of International Roadmap of Devices and Systems (IRDS) 2018 Edition.
Phys. Rev. Appl. 13, 064021 (2020).
Phys. Rev. Appl. 13, 054030 (2020).
Phys. Rev. B 101, 035422 (2020).
Appl. Phys. Lett. 115, 241601 (2019).
Electron transport, injection and tunneling in quantum material heterostructures
The nonparabolic band structure, reduced dimensionality, and exotic quantum degree of freedom (such as valley) in exotic solids, such as 2D and topological materials, has led to myriads of unusual transport phenomena. In this project, we study a large variety of transport phenomena covering both semiclassical (e.g. thermionic injection and space-charge-limited transport) and quantum (e.g. ballistic tunneling and field-induced emission) regime in 2D and topological nanostructures. We are searching for scaling laws that are useful for the conceptual understanding and the experimental characterization of charge transport and injection phenomena in nanostructures. The goal of this project is to create a new library of solid-state physics models for 2D and topological materials, thus paving the foundation for next-generation semiconductor TCAD modeling tools.
Phys. Rev. Lett. 121, 056802 (2018). Selected as PRL "Featured in Physics" and "Editors' Suggestions".
InfoMat 3, 502 (2021). [2020 Impact Factor: 25.405]
Phys. Rev. Appl. 12, 014057 (2019).
MRS Bullet. 42, 505 (2017).
Phys. Rev. B 93, 041422(R) (2016). Rapid Communications
Phys. Rev. B 88, 245404 (2015).
Advanced nanomaterial photonics for future wireless networks
The exotic optical properties of 2D materials and their heterostructures, such as the exceptionally strong optical nonlinearity, excellent optical response in the THz regime, and gate-tunable electron-photon interactions, have brought exciting opportunities to the optical science and technology. Our recent works have also shed new light on the exceptional nonlinearity of three-dimensional topological Dirac/Weyl semimetals in the THz regime. In this project, we study the linear and nonlinear optical response of a large variety of 2D and topological materials. Particular emphases are made to uncover the potential of these novel optical materials as GHz and THz photonic and optoelectronic devices (such as metasurface, photonic crystal and photodetector) that are critical for the development of "5G and Beyond" wireless communication networks.
Phys. Rev. Research 2, 043252 (2020).
Chinese Phys. B 29, 077802 (2020). [Invited Article]
APL Photon. 4, 034402 (2019).
Opt. Expr. 27, 38270 (2019).
Designing topological electrical circuits
Collaborative project with NUS theory group led by Prof. Ching Hua Lee
Electrical circuit has recently emerged as a novel platform to synthesize exotic topological phases, non-Hermitian and chaotic systems that are difficult to realize in material. In this collaborative project, we perform circuit design, simulation, fabrication and measurement of exotic electrical circuits with unusual topological properties. We employ advanced circuit design and machine learning to achieve the experimental realization of high-complexity topological electrical circuit.
Nature Communications 11, 4385 (2020). Selected as "Editors' Focus" article
A Better World by Design. SUTD