Publications (31)
Imaging nodal knots in momentum space through topolectrical circuits
Ching Hua Lee, Amanda Sutrisno, Tobias Hofmann +7
Knots are intricate structures that cannot be unambiguously distinguished with any single topological invariant. Momentum space knots, in particular, have been elusive due to their…
Ultracompact Vanadium Dioxide Dual-Mode Plasmonic Waveguide Electroabsorption Modulator
Kelvin J. A. Ooi, Ping Bai, Hong Son Chu +1
Subwavelength modulators play an indispensable role in integrated photonic-electronic circuits. Due to weak light-matter interactions, it is always a challenge to develop a modulat…
Strongly correlated multi-electron bunches from interaction with quantum light
Suraj Kumar, Jeremy Lim, Nicholas Rivera +4
Strongly correlated electron systems are a cornerstone of modern physics, being responsible for groundbreaking phenomena from superconducting magnets to quantum computing. In most…
Unconventional tunnel magnetoresistance scaling with altermagnets
Zongmeng Yang, Xingyue Yang, Jianhua Wang +7
In conventional magnetic tunnel junctions (MTJs), the tunnel magnetoresistance (TMR) typically increases with barrier thickness as electron transmission in the antiparallel configu…
Human or AI? Comparing Design Thinking Assessments by Teaching Assistants and Bots
Sumbul Khan, Wei Ting Liow, Lay Kee Ang
As design thinking education grows in secondary and tertiary contexts, educators face the challenge of evaluating creative artefacts that combine visual and textual elements. Tradi…
Nonlinear Magnetic Orbital Hall Effect Induced by Spin-Orbit Coupling
Hui Wang, Huiying Liu, Yanfeng Ge +6
Electrical readout of 180 switching in strictly compensated collinear antiferromagnets remains a major challenge in antiferromagnetic spintronics. Electrical writing of per…
Quantum Metric Nonlinear Spin-Orbit Torque Enhanced by Topological Bands
Xukun Feng, Weikang Wu, Hui Wang +5
Effects manifesting quantum geometry have been a focus of physics research. Here, we reveal that quantum metric plays a crucial role in nonlinear electric spin response, leading to…
Design of a Monopole Antenna Based Resonant Nanocavity for Detection of Optical Power from Hybrid Plasmonic Waveguides
Kelvin J. A. Ooi, Ping Bai, Ming Xia Gu +1
A novel plasmonic waveguide-coupled nanocavity with a monopole antenna is proposed to localize the optical power from a hybrid plasmonic waveguide and subsequently convert it into…
Propagation-induced limits to high harmonic generation in 3D Dirac semimetals
Jeremy Lim, Yee Sin Ang, Lay Kee Ang +1
3D Dirac semimetals (DSMs) are promising materials for terahertz high harmonic generation (HHG). We show that 3D DSMs' high nonlinearity opens up a regime of nonlinear optics where…
Mid-infrared Active Graphene Nanoribbon Plasmonic Waveguide Devices
Kelvin J. A. Ooi, Hong Son Chu, Lay Kee Ang +1
Doped graphene emerges as a strong contender for active plasmonic material in the mid-infrared wavelengths due to the versatile external-control of its permittivity-function and al…
A new coupling mechanism between two graphene electron waveguides for ultrafast switching
Wei Huang, Shi-Jun Liang, Elica Kyoseva +1
We propose a novel ultrafast electronic switching device based on dual-graphene electron waveguides, in analogy to the optical dual-channel waveguide device. The design utilizes th…
Out-of-Plane Nonlinear Orbital Hall Torque
Hui Wang, Xukun Feng, Jin Cao +5
Despite recent advances in orbitronics, generating out-of-plane orbital torques essential for field-free deterministic switching of perpendicular magnetization remains a key challe…
Plasmonic coupled-cavity system for enhancement of surface plasmon localization in plasmonic detectors
Kelvin J. A. Ooi, Ping Bai, Ming Xia Gu +1
A plasmonic coupled-cavity system, which consists of a quarter-wave coupler cavity, a resonant Fabry-Perot detector nanocavity, and an off-resonant reflector cavity, is used to enh…
Intrinsic Dynamic Generation of Spin Polarization by Time-Varying Electric Field
Xukun Feng, Jin Cao, Zhi-Fan Zhang +5
Electric control of spin in insulators is desired for low-consumption and ultrafast spintronics, but the underlying mechanism remains largely unexplored. Here, we propose an intrin…
Adiabatic control of surface plasmon-polaritons in a 3-layers graphene curved configuration
Wei Huang, Shi-Jun Liang, Elica Kyoseva +1
In this paper, we utilize coupled mode theory (CMT) to model the coupling between surface plasmon-polaritons (SPPs) between multiple graphene sheets. By using the Stimulated Raman…
Designing Efficient Metal Contacts to Two-Dimensional Semiconductors MoSiN and WSiN Monolayers
Qianqian Wang, Liemao Cao, Shi-Jun Liang +8
Metal contacts to two-dimensional (2D) semiconductors are ubiquitous in modern electronic and optoelectronic devices. Such contacts are, however, often plagued by strong Fermi leve…
Designing a Concentrated High-Efficiency Thermionic Solar Cell Enabled by Graphene Collector
Xin Zhang, Xiaohang Chen, Jinchan Chen +2
We propose a concentrated thermionic emission solar cell design, which demonstrates a high solar-to-electricity energy conversion efficiency larger than 10\% under 600 sun, by harn…
Asymmetric Schottky Contacts in Bilayer MoS2 Field Effect Transistors
Antonio Di Bartolomeo, Alessandro Grillo, Francesca Urban +8
We discuss the high-bias electrical characteristics of back-gated field-effect transistors with CVD-synthesized bilayer MoS2 channel and Ti Schottky contacts. We find that oxidized…
Designing 24-hour Electrical Power Generator: Thermoradiative Device for Harvesting Energy from Sun and Outer Space
Xin Zhang, Guofeng Yang, Mengqi Yan +2
Energy harvesting from sun and outer space using thermoradiative devices (TRD), despite being promising renewable energy sources, are limited only to daytime and nighttime period,…
Thickness dependence of space-charge-limited current in spatially disordered organic semiconductors
Muhammad Zubair, Yee Sin Ang, Lay Kee Ang
Charge transport properties in organic semiconductors are determined by two kinds of microscopic disorders, namely energetic disorder related to the distribution of localized state…
Revised diode equation for Ideal Graphene-Semiconductor Schottky Junction
Shi-Jun Liang, Lay Kee Ang
In this paper we carry out a theoretical and experimental study of the nature of graphene/semiconductor Schottky contact. We present a simple and parameter-free carrier transport m…
Electro-optical graphene plasmonic logic gates
Kelvin J. A. Ooi, Hong Son Chu, Ping Bai +1
The versatile control of graphene's plasmonic modes via an external gate-voltage inspires us to design efficient electro-optical graphene plasmonic logic gates at the midinfrared w…
Nonperturbative Magnetic Orbital Hall Effect in Altermagnets
Xukun Feng, Jin Cao, Lay Kee Ang +3
Recent studies on altermagnets have focused considerable attention on nonrelativistic effects that persist in the absence of spin-orbit coupling (SOC). As a result, the relative im…
Highly Efficient Midinfrared On-Chip Electrical Generation of Graphene Plasmons by Inelastic Electron Tunneling Excitation
Kelvin J. A. Ooi, Hong Son Chu, Chang Yu Hsieh +2
Inelastic electron tunneling provides a low-energy pathway for the excitation of surface plasmons and light emission. We theoretically investigate tunnel junctions based on metals…
Design of an optimized -based highly sensitive near-infrared surface plasmon resonance imaging biosensor
Yi Xu, Lin Wu, Lay Kee Ang
A surface plasmon resonance imaging biosensor based on deposited on Aluminium substrate is designed for high imaging sensitivity and detection accuracy. The proposed…
Cataloguing MoSiN and WSiN van der Waals Heterostructures: An Exceptional Material Platform for Excitonic Solar Cell Applications
Che Chen Tho, Chenjiang Yu, Qin Tang +14
Two-dimensional (2D) materials van der Waals heterostructures (vdWHs) provides a revolutionary route towards high-performance solar energy conversion devices beyond the conventiona…
Semiconductor-to-metal transition in bilayer MoSiN and WSiN with strain and electric field
Qingyun Wu, Liemao Cao, Yee Sin Ang +1
With exceptional electrical and mechanical properties and at the same time air-stability, layered MoSi2N4 has recently draw great attention. However, band structure engineering via…
High-Efficiency Van Der Waals heterostructure Thermionic Device With Graphene Electrodes
Shi-Jun Liang, Lay Kee Ang
In this paper, we propose van del Waals heterostructure-based thermionic devices for the applications in cooling and power generation in the temperature range of 300 to 400 K. By u…
Co-Designing Interdisciplinary Design Projects with AI
Wei Ting Liow, Sumbul Khan, Lay Kee Ang
Creating interdisciplinary design projects is time-consuming and cognitively demanding for teachers, requiring curriculum alignment, cross-subject integration, and careful sequenci…
Quantum Transport in Two-Dimensional WS with High-Efficiency Carrier Injection Through Indium Alloy Contacts
Chit Siong Lau, Jing Yee Chee, Yee Sin Ang +8
Two-dimensional transition metal dichalcogenides (TMDCs) have properties attractive for optoelectronic and quantum applications. A crucial element for devices is the metal-semicond…
Waveguide engineering of graphene's nonlinearity
Kelvin J. A. Ooi, Lay Kee Ang, Dawn T. H. Tan
Graphene has recently been shown to possess giant nonlinearity; however, the utility of this nonlinearity is limited due to high losses and small interaction volume. We show that b…