Summary
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.
Figure 1. Sample device geometry. MoTe2 flakes of various thicknesses are transferred on prepatterned gold electrodes deposited on a hexagonal boron nitride (BN)/graphite (Gr) heterostructure and capped with single-layer hBN. The bottom layers provide an ultra-flat substrate for the MoTe2.
Related Content
Mesoscopic systems as coherent control elements
Summary Mesoscopic systems provide a new tool for quantum systems design. In particular, they are enabling of robust quantum control. Here “mesoscopic system” refers to a connected network where each element, if studied alone, would be a quantum bit. The network is too big to be treated fully quantum mechanically. We do not have individual […]
September 1, 2016
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
Quantum Light Sources Based on Deterministic Photon Subtraction
Summary This project develops new sources of light that utilize quantum entanglement to enhance imaging resolution and detection. We aim to go beyond simple photon pairs and advance our understanding and control of new quantum states of light. Our approach uses deterministic single-photon subtraction (removing of a specific photon from a pulse of light) […]
July 13, 2018
Composite Superconductors for Improved Quantum Coherence
Summary Conventional superconductors have trouble performing well in magnetic fields required for electron spin resonance (ESR) – based quantum information processing applications. We can, however, use proximity engineering to select desired properties from different materials and combine them for improved superconducting performance in magnetic fields — an improvement that would have strong implications for […]
December 12, 2018