Research and Development of WTe₂ Platform for Generation of Majorana Particles

Abstract

The gapless electronic states in the topological insulators (TI) with symmetry protection are the viable platform for Majorana qubits in future fault-tolerant topological quantum computation. Among transition metal dichalcogenides, tungsten ditelluride (WTe₂), which has a large spin-orbit coupling, is considered as a promising material for such TI. In this report, we introduce our recent research on WTe₂ platform. We report on a heterostructure of WTe₂ and superconducting material with high quality, using spontaneous formation of superconducting PdTe. We demonstrate Josephson junction devices with weak links for multi-layer WTe₂. We show the electronic states of monolayer and bilayer Td-WTe₂ using density functional theory. These Td-WTe₂ layers can exhibit quantum spin Hall states depending on the directions of stripes and step edges, which expands the availability of WTe₂. These studies deepen the process technology and material science of WTe₂, which will pave the way for realizing a platform for Majorana particles.