Long-lived memory for electronic spin in a quantum dot: Numerical analysis

TL;DR

This paper numerically investigates how electron spins in quantum dots can be stored in nuclear spin states, considering realistic errors like incomplete polarization and hyperfine interaction variations, showing feasible fidelity levels.

Contribution

It provides a numerical analysis of electron spin storage in nuclear spins in quantum dots, accounting for realistic imperfections and demonstrating achievable fidelities.

Findings

Reasonable fidelities are achievable with modest nuclear bath polarization.

Imperfections such as incomplete polarization and hyperfine variations impact fidelity but can be mitigated.

Numerical results guide practical implementations of spin-based quantum memory.

Abstract

Techniques for coherent control of electron spin-nuclear spin interactions in quantum dots can be directly applied in spintronics and in quantum information processing. In this work we study numerically the interaction of electron and nuclear spins in the context of storing the spin-state of an electron in a collective state of nuclear spins. We take into account the errors inherent in a realistic system: the incomplete polarization of the bath of nuclear spins and the different hyperfine interactions between the electron and individual nuclei in the quantum dot. Although these imperfections deteriorate the fidelity of the quantum information retrieval, we find reasonable fidelities are achievable for modest bath polarizations.