Single photoelectron spin detection and angular momentum transfer in a gate defined quantum dot

TL;DR

This paper demonstrates the detection of single electron spins generated by polarized photons in a quantum dot system, showing potential for coherent quantum state transfer between photons and spins.

Contribution

It reports the first experimental verification of angular momentum transfer from single photons to single electron spins in a gate-defined quantum dot system.

Findings

Single photoelectron spin detection achieved

Angular momentum transfer from photon to electron confirmed

Potential for quantum state transfer and hybrid quantum technology

Abstract

Recent innovations in fabricating nanoscale confined spin systems have enabled investigation of fundamental quantum correlations between single quanta of photons and matter states. Realization of quantum state transfer from photon polarization to electron spin using gate defined quantum dots (QDs) may give evidence of preserved coherence of angular momentum basis states at the photon-spin interface. The interface would enlarge the concept of quantum information technology, in which single photogenerated electron spins are manipulated with the dots, but this remains a serious challenge. Here, we report the detection of single electron spins generated by polarized single photons via a double QD (DQD) to verify the angular momentum transfer from single photons to single electrons. Pauli spin blockade (PSB) is used to project the photoelectron spin state onto the up or down spin state. Our result promises the realization of coherent quantum state transfer and development of hybrid photon and spin quantum technology.