Determining the electronic triplet-singlet transition probability in double quantum dots: Analogy with the double slit experiment

TL;DR

This paper investigates the triplet-singlet transition probability in double quantum dots mediated by hyperfine interaction, highlighting the role of local hyperfine effects and nuclear back-action in quantum state interference.

Contribution

It introduces an elementary measurement scheme to analyze hyperfine-induced transitions and clarifies the distinct effects of hyperfine interaction versus magnetic field mixing.

Findings

Hyperfine interaction's local character affects transition probabilities.

Nuclear back-action cancels destructive interference in transitions.

Hyperfine interaction differs from magnetic field effects in state mixing.

Abstract

We apply an elementary measurement scheme to calculate the electronic triplet-singlet transition mediated by hyperfine interaction in a double quantum dot. We show how the local character of the hyperfine interaction and the nuclear back-action process (flip-flop) are crucial to cancel destructive interferences of the triplet-singlet transition probability. It is precisely this cancellation which differentiates the hyperfine interaction from an anisotropic magnetic field which mixes the triplet and the singlet eigenstates.