Role of interference in quantum state transfer through spin chains

TL;DR

This paper investigates how quantum interference affects state transfer in various finite spin chains, finding that perfect transfer can occur with minimal interference, challenging previous assumptions about the necessity of interference.

Contribution

It demonstrates that high-fidelity quantum state transfer in spin chains can be achieved with negligible interference, providing new insights into quantum communication mechanisms.

Findings

Perfect state transfer can occur without quantum interference.

Spin chains can realize interference-free quantum state transfer.

Interference is not essential for high-fidelity transfer.

Abstract

We examine the role that interference plays in quantum state transfer through several types of finite spin chains, including chains with isotropic Heisenberg interaction between nearest neighbors, chains with reduced coupling constants to the spins at the end of the chain, and chains with anisotropic coupling constants. We evaluate quantitatively both the interference corresponding to the propagation of the entire chain, and the interference in the effective propagation of the first and last spins only, treating the rest of the chain as black box. We show that perfect quantum state transfer is possible without quantum interference, and provide evidence that the spin chains examined realize interference-free quantum state transfer to a good approximation.