Symposium QT01: Development of 2D Quantum Materials Pipelines (2D-QMaPs)

Louis Gaudreau, National Research Council Canada

Valley-Spin Polarization in Monolayer WSe₂

Written by Kwon-Teen Chen

Louis Gaudreau from the National Research Council Canada spoke about the challenges with different monolayer transition metal dichalcogenides (TMDs) for quantum circuits. He found that when fabricating, atomic force microscopy (AFM) produced noise if the material was not properly cleaned. During the tests, Gaudreau found WSe₂ would be spin-polarized to a factor of 5 before the spin would level out to being non-polarized, which is different from other TMDs that he had seen. He also found that in the electrostatic confinement, the contacts would populate with holes. When magnetic field was applied to the one-dimensional channels in the monolayer, the steps would become e²/h which was half of the step without a magnetic field. One of the issues Gaudreau was having was his yield has been very low and the process of making the devices is very slow and painful. He has also found that he can control his gated quantum dots, but he cannot yet place them.