The library of two-dimensional (2D) materials has recently grown to include topological insulators and semimetals. Their incorporation in special device geometries may lead to novel quantum electronics with enhanced functionalities. Weyl semimetals, in particular, offer the most robust form of topological protection. Recent results from our group indicate that Weyl nodes should be observable at room temperature in thin molybdenum ditelluride (MoTe2) and are furthermore tunable by changing dimensionality. Weyl nodes correspond to points of bulk band degeneracy and are separated in momentum space. In this joint project with Dr. Andrea Damascelli’s group at the University of British Columbia (UBC), we utilize micro-angle-resolved photoemission spectroscopy (micro-ARPES) to image in momentum space the Weyl nodes and surface arcs of MoTe2 and further investigate changes induced by lower dimensionality. Once the Weyl nodes are mapped, we perform transport measurements and utilize scanning photocurrent microscopy to image novel photogalvanic effects induced by the Weyl points in real space. We expect this project will pave the way for future materials exploration and device development that exploits the unique properties of 2D materials through combined ARPES and nanoscale device transport studies.
Development of Terahertz Polariton Lasers
Theoretical and experimental results show that the polariton lasing mechanism is a promising basis for a compact, efficient source of terahertz radiation.
July 1, 2017
Metasurfaces for high-efficiency parametric downconversion and complex quantum state generation
Summary Entangled photon sources are crucial for quantum computing, quantum sensing, and quantum communication. Of growing importance are sources relying on spontaneous parametric downconversion (SPDC). Unfortunately, these sources of entangled photons are often constrained by momentum conservation laws. To overcome this limitation and expand the possibility of quantum state engineering, we intend to use metasurfaces […]
February 1, 2023
Rydberg Atom Array Quantum Simulator
Summary Quantum simulators enable probing the static and dynamic properties of correlated quantum many-body systems that would otherwise be numerically inaccessible using classical simulators. We are developing quantum simulators based on arrays of neutral atoms excited to Rydberg states. Such Rydberg atom arrays are advantageous for simulating the dynamics of interacting spin systems (Ising spin […]
February 27, 2020
Quantum Sensing with Small Quantum Systems
Summary There are small quantum systems over which we have very good control and which have long lifetimes. Examples include the phosphorous (P) defect in silicon (Si) and the nitrogen vacancy (NV) defect in diamond. With P defect in Si, we focus on improving our understanding of the hyperpolarization mechanism to better enable engineering of […]
December 1, 2016