Si-MOSFET Achieves 90% Intervalley Mixing in Silicon Quantum Hall Channels

Researchers at NTT, Inc. have demonstrated a high degree of interaction within silicon quantum Hall channels, with a transition probability close to 1, indicating nearly complete equilibration between two valley edge channels. This result, obtained using a double-layer-gated silicon metal-oxide-semiconductor field-effect transistor, brings the creation of compact silicon quantum Hall interferometers closer to realization. The experiment brought spin-polarized valley edge channels into close proximity, revealing that interchannel transport between channels with differing spin orientations showed negligible transition probability, confirming the suppression of spin-flip scattering expected in silicon. These findings demonstrate that intervalley coupling at a silicon/silicon dioxide interface can function as a beam-splitter, establishing a key component for future quantum devices. Nearly complete equilibration between valley edge…