Integrability-based analysis of the hyperfine-interaction -nduced decoherence in quantum dots

TL;DR

This paper employs the Algebraic Bethe Ansatz and Monte Carlo methods to analyze how hyperfine interactions cause decoherence in quantum dots, revealing a crossover from strong to weak magnetic fields with non-decaying coherence.

Contribution

It introduces an integrability-based approach combined with Monte Carlo sampling to study decoherence in quantum dots, highlighting a crossover regime with unique coherence properties.

Findings

Identification of a crossover from strong to weak magnetic field regimes.

Discovery of a large non-decaying coherence factor in certain conditions.

Explanation of the zero frequency peak's robustness against broadening.

Abstract

Using the Algebraic Bethe Ansatz in conjunction with a simple Monte Carlo sampling technique, we study the problem of the decoherence of a central spin coupled to a nuclear spin bath. We describe in detail the full crossover from strong to weak external magnetic field field, a limit where a large non-decaying coherence factor is found. This feature is explained by Bose-Einstein-condensate-like physics which also allows us to argue that the corresponding zero frequency peak would not be broadened by statistical or ensemble averaging.