Demonstration of long-range correlations via susceptibility measurements in a one-dimensional superconducting Josephson spin chain

TL;DR

This paper demonstrates that a superconducting flux circuit spin chain can support long-range correlations and mediate interactions between distant qubits, advancing quantum connectivity methods.

Contribution

It introduces a superconducting flux circuit implementation of a spin chain that exhibits long-range correlations and mediates qubit interactions, with potential for quantum computing.

Findings

Long-range, cross-chain correlations observed via susceptibility measurements.

Interactions between end qubits mediated by the chain demonstrated.

Potential application in quantum annealing processors for long-range qubit coupling.

Abstract

Spin chains have long been considered an effective medium for long-range interactions, entanglement generation, and quantum state transfer. In this work, we explore the properties of a spin chain implemented with superconducting flux circuits, designed to act as a connectivity medium between two superconducting qubits. The susceptibility of the chain is probed and shown to support long-range, cross chain correlations. In addition, interactions between the two end qubits, mediated by the coupler chain, are demonstrated. This work has direct applicability in near term quantum annealing processors as a means of generating long-range, coherent coupling between qubits.