Quantum state transfer on distance regular spin networks with intrinsic decoherence

TL;DR

This paper studies how intrinsic decoherence affects quantum state transfer in distance-regular spin networks, showing that decoherence degrades perfect transfer but fidelity stabilizes over time, depending on network distance and decoherence rate.

Contribution

It extends the analysis of quantum state transfer to distance-regular graphs considering intrinsic decoherence, revealing steady-state fidelity behavior and the impact of network parameters.

Findings

Decoherence destroys perfect state transfer channels.

Fidelity reaches a steady value over time, independent of decoherence rate.

Fidelity decreases with increasing distance between sender and receiver.

Abstract

By considering distance-regular graphs as spin networks, we investigate the state transfer fidelity in this class of networks. The effect of environment on the dynamics of state transfer is modeled using Milburn's intrinsic decoherence [G. J. Milburn, Phys. Rev. A 44, 5401 (1991)]. We consider a particular type of spin Hamiltonians which are extended version of those of Christandl et al [Phys. Rev. A 71, 032312 (2005)]. It is shown that decoherence destroys perfect communication channels. Using optimal coupling strengths derived by Jafarizadeh and Sufiani [Phys. Rev. A 77, 022315 (2008)], we show that destructive effect of environment on the communication channel increases by increasing the decoherence rate, however the state transfer fidelity reaches a steady value as time approaches infinity which is independent of the decoherence rate. Moreover, it is shown that for a given decoherence rate, the fidelity of transfer decreases by increasing the distance between the sender and the receiver.