Analytic next-to-nearest neighbour XX models with perfect state transfer and fractional revival

TL;DR

This paper extends non-uniform spin chains with next-to-nearest neighbour couplings, demonstrating analytically that perfect quantum state transfer and fractional revival are achievable, which is relevant for experimental quantum information processing.

Contribution

It introduces an analytical extension of spin chains to include NNN couplings while preserving perfect state transfer and fractional revival capabilities.

Findings

Perfect state transfer is maintained with NNN couplings.

End-to-end entanglement (fractional revival) can occur in extended chains.

Analytical proof supports experimental feasibility.

Abstract

Certain non-uniformly coupled spin chains can exhibit perfect transfer of quantum states from end to end. Motivated by recent experimental implementations, we extend the simplest such chain to next-to-nearest neighbour (NNN) couplings. It is shown analytically that perfect state transfer can be maintained under the extension and that end-to-end entanglement generation (fractional revival) can occur.