Phys.org March 31, 2021
An international team of researchers (UK, France) measured an electron spin in a singly occupied gate-defined quantum dot, fabricated using CMOS-compatible processes at the 300-mm wafer scale. For readout, they used spin-dependent tunneling combined with a low-footprint single-lead quantum-dot charge sensor, measured using rf gate reflectometry. They demonstrated spin readout in two devices using this technique, obtaining valley splittings in the range 0.5–0.7 meV using excited-state spectroscopy, and measured a maximum electron-spin relaxation time. These long lifetimes indicate the silicon-nanowire geometry and fabrication processes employed here show a great deal of promise for qubit devices, while the spin-readout method demonstrated here is well suited to a variety of scalable architectures. The discovery provides a blueprint to shortcut to industrial scale quantum chip production…read more. Open Access TECHNICAL ARTICLE
Device and measurement setup. Credit: PRX Quantum 2, 010353, 31 March 2021