Optical initialization of hole spins in p-doped quantum dots: orientation efficiency and loss of coherence

TL;DR

This paper theoretically investigates the efficiency and coherence loss in optical hole spin initialization in p-doped quantum dots, considering pulse excitation and phonon effects, and identifies optimal parameters for maximal orientation.

Contribution

It provides a detailed theoretical analysis of spin initialization efficiency and coherence loss mechanisms, including temperature and detuning effects, in p-doped quantum dots.

Findings

Dephasing to orientation ratio depends on temperature and detuning.

Optimal excitation parameters are identified.

Coherence loss occurs during pulse excitation and phonon interactions.

Abstract

We study theoretically the recently proposed hole spin initialization scheme for $p$-doped quantum well or dot systems via coupling to trion states with sub-picosecond circularly polarized laser pulses. We analyze the efficiency of spin initialization an predict the intrinsic spin coherence loss due to the pulse excitation itself as well as the phonon-induced spin dephasing, both taking place on the timescale of the driving laser pulse. We show that the ratio of the degree of dephasing to the achieved orientation effect does not depend on the pulse area but is sensitive to the temperature and detuning. The optimal excitation parameters are identified.