Perfect state transfer in long-range interacting spin chains

TL;DR

This paper explores conditions for perfect quantum state transfer in long-range ferromagnetic spin chains, proposing an optimization scheme to approximate ideal transfer with practical interaction strengths.

Contribution

It introduces a scalable, implementable optimization method to enhance state transfer fidelity in long-range spin chains, addressing practical limitations.

Findings

Identified conditions for perfect state transfer in long-range chains

Proposed an optimization scheme to improve transfer fidelity

Scheme is scalable and feasible for larger systems

Abstract

We investigate the most general conditions under which a finite ferromagnetic long-range inter- acting spin chain achieves unitary fidelity and the shortest transfer time in transmitting an unknown input qubit. A deeper insight into system dynamics, allows us to identify an ideal system involving sender and receiver only. However, this two-spin ideal chain is unpractical due to the rapid decrease of the coupling strength with the distance. Therefore, we propose an optimization scheme for ap- proaching the ideal behaviour, while keeping the interaction strength still reasonably high. The procedure is scalable with the size of the system and straightforward to implement.