Perfect, Pretty Good and Optimized Quantum State Transfer in Transmon qubit chains

TL;DR

This paper investigates how adjusting interaction strengths in transmon qubit chains can achieve perfect or near-perfect quantum state transfer, revealing connections to topological states and optimizing transfer times.

Contribution

It provides explicit analytic expressions for transmission fidelity and explores the relationship between interaction patterns, topological properties, and transfer speed in transmon chains.

Findings

Adjusting interaction strength enables perfect or pretty good state transfer.

Chains with dimerized interactions can be optimized for fast transfer times.

Topological states are not always necessary for rapid quantum state transfer.

Abstract

Chains of transmon qubits are considered promising systems to implement different quantum information tasks. In particular as channels that perform high-quality quantum state transfer. We study how changing the interaction strength between the chain qubits allows us to obtain perfect or pretty good state transfer and present explicit analytic expressions for their transmission fidelity. For particular values of the interactions between the qubits, transmon chains are equivalent to generalized SSH chains and show the traditional traits observed in chains with topological states, localized states at the extremes of the chain, and eigenvalues that lie inside the spectral gap. Consequently, we study the quantum state transfer on chains with dimerized interactions, looking for chains with fast transfer times. We show that, in many cases, asking for fast transfer times results in chains with dimerized interactions that do not have topological states.