Excitation- and state-transfer through spin chains in the presence of spatially correlated noise

TL;DR

This paper studies how spatially correlated environmental noise affects excitation and state transfer in spin chains, revealing new dynamics, decoherence-free subspaces, and the impact on transfer quality.

Contribution

It introduces analysis of spatially correlated noise effects on spin networks, highlighting new decoherence-free subspaces and transfer behavior.

Findings

Emergence of decoherence-free subspaces with increasing correlation length

Relaxation blocking of spins by surrounding spins due to correlated noise

Qualitatively different effects of dephasing and dissipation on state transfer

Abstract

We investigate the influence of environmental noise on spin networks and spin chains. In addition to the common model of an independent bath for each spin in the system we also consider noise with a finite spatial correlation length. We present the emergence of new dynamics and decoherence-free subspaces with increasing correlation length for both dephasing and dissipating environments. This leads to relaxation blocking of one spin by uncoupled surrounding spins. We then consider perfect state transfer through a spin chain in the presence of decoherence and discuss the dependence of the transfer quality on spatial noise correlation length. We identify qualitatively different features for dephasing and dissipative environments in spin-transfer problems.