Single-shot initialization of electron spin in a quantum dot using a short optical pulse

TL;DR

This paper introduces a method for rapidly initializing an electron spin in a quantum dot using a single short optical pulse, leveraging cavity-enhanced desexcitation for high speed and fidelity.

Contribution

It presents a theoretical scheme for single-shot electron spin initialization in quantum dots with optimized pulse parameters and cavity effects.

Findings

Initialization possible with pulses as short as tens of picoseconds

Theoretical limits on rate and fidelity are derived

Optimal pulse area for initialization is identified

Abstract

We propose a technique to initialize an electron spin in a semiconductor quantum dot with a single short optical pulse. It relies on the fast depletion of the initial spin state followed by a preferential, Purcell-accelerated desexcitation towards the desired state thanks to a micropillar cavity. We theoretically discuss the limits on initialization rate and fidelity, and derive the pulse area for optimal initialization. We show that spin initialization is possible using a single optical pulse down to a few tens of picoseconds wide.