Selective Dynamic Nuclear Spin Polarization in Spin-Blocked Double-Dot

TL;DR

This paper investigates how nuclear spin polarization occurs in spin-blocked double quantum dots, highlighting the role of quadrupole coupling caused by indium doping in explaining experimental NMR observations.

Contribution

It introduces a model that includes nuclear quadrupole coupling effects to explain nuclear spin polarization phenomena in double quantum dots.

Findings

Quadrupole coupling explains missing arsenic NMR signals.

Hyperfine transition rates are calculated considering quadrupole effects.

Indium doping influences nuclear spin polarization in quantum dots.

Abstract

We study the mechanism of dynamical nuclear spin polarization by hyperfine interaction in spin-blocked double quantum dot system. We calculate the hyperfine transition rates and solve the master equations for the nuclear spins. Specifically, we incorporate the effects of the nuclear quadrupole coupling due to the doping-induced local lattice distortion and strain. Our results show that nuclear quadrupole coupling induced by the 5% indium substitution can be used to explain the recent experimental observation of missing arsenic NMR signal in the spin-blocked double dots.