Emergent Decoherence Dynamics in Doubly Disordered Spin Networks

TL;DR

This paper uncovers an emergent decoherence law in disordered spin networks, revealing how microscopic interactions lead to macroscopic irreversibility and demonstrating control over decoherence channels for quantum memory applications.

Contribution

It introduces a new decoherence law in doubly disordered spin networks and shows how to control decoherence pathways via Floquet engineering and environment modulation.

Findings

Emergent decoherence law: $e^{-\sqrt{R_{p}t}}e^{-R_{d}t}$.

Disorder can localize polarization and extend coherence.

Control of decoherence channels is achievable through engineered interventions.

Abstract

Elucidating the emergence of irreversible macroscopic laws from reversible quantum many-body dynamics is a question of broad importance across all quantum science. Many-body decoherence plays a key role in this transition, yet connecting microscopic dynamics to emergent macroscopic behavior remains challenging. Here, in a doubly disordered electron-nuclear spin network, we uncover an emergent decoherence law for nuclear polarization, $e^{-\sqrt{R_{p}t}}e^{-R_{d}t}$, that is robust across broad parameter regimes. We trace its microscopic origins to two interdependent decoherence channels: long-range interactions mediated by the electron network and spin transport within the nuclear network exhibiting anomalous, sub-diffusive dynamics. We demonstrate the capacity to control--and even eliminate--either channel individually through a combination of Floquet engineering and (optical) environment modulation. We find that disorder, typically viewed as detrimental, here proves protective, generating isolated electron-free clusters that localize polarization and prolong coherence lifetimes. These findings establish a microscopic framework for manipulating decoherence pathways and suggests engineered disorder as a new design principle for realizing long-lived quantum memories and sensors.