Optical pumping of quantum dot nuclear spins

TL;DR

This paper proposes an all-optical method inspired by atomic laser cooling techniques to polarize nuclear spins in quantum dots, aiming to suppress hyperfine-induced electron spin decoherence.

Contribution

It introduces a novel optical scheme for nuclear spin polarization in quantum dots based on a controlled Overhauser effect, extending atomic cooling concepts to solid-state systems.

Findings

The scheme can effectively polarize nuclear spins in quantum dots.

Potential to significantly reduce electron spin decoherence.

Provides a new approach for quantum information applications.

Abstract

An all-optical scheme to polarize nuclear spins in a single quantum dot is analyzed. The hyperfine interaction with randomly oriented nuclear spins presents a fundamental limit for electron spin coherence in a quantum dot; by cooling the nuclear spins, this decoherence mechanism could be suppressed. The proposed scheme is inspired by laser cooling methods of atomic physics and implements a "controlled Overhauser effect" in a zero-dimensional structure.