High resolution coherent population trapping on a single hole spin in a semiconductor

TL;DR

This paper demonstrates high-resolution coherent population trapping on a single hole spin in a semiconductor quantum dot, revealing slow spin dephasing caused by charge noise, with implications for quantum information applications.

Contribution

It provides the first high-resolution CPT measurement on a single hole spin and identifies charge noise as a key dephasing mechanism in this system.

Findings

Dark state absorption dip width of 10 MHz

Evidence of slow spin dephasing due to charge noise

Charge noise significantly affects hole spin coherence

Abstract

We report high resolution coherent population trapping on a single hole spin in a semiconductor quantum dot. The absorption dip signifying the formation of a dark state exhibits an atomic physics-like dip width of just 10 MHz. We observe fluctuations in the absolute frequency of the absorption dip, evidence of very slow spin dephasing. We identify this process as charge noise by, first, demonstrating that the hole spin g-factor in this configuration (in-plane magnetic field) is strongly dependent on the vertical electric field, and second, by characterizing the charge noise through its effects on the optical transition frequency. An important conclusion is that charge noise is an important hole spin dephasing process.