Strong coupling between two spin ensembles via a large Josephson junction

TL;DR

This paper presents a method to strongly couple two spin ensembles via a large Josephson junction, enabling fast high-fidelity quantum gates for quantum information processing.

Contribution

It introduces a novel approach to achieve strong coupling between spin ensembles through a large Josephson junction, facilitating efficient quantum gate operations.

Findings

High-fidelity two-qubit phase gate within 0.41 ns

π phase-swap gate achieved in 103.11 ns with >99% fidelity

Demonstrates strong coupling and quantum gate implementation in spin-Josephson systems

Abstract

We propose a method to achieve strong coupling between a spin ensemble and a large Josephson junctions (LJJ). Then, the strong coupling between two spin ensembles can be induced by a LJJ. A non-adiabatic holonomic single-qubit quantum gates is realized. Moreover, with the dispersive interaction between the spin ensembles and the LJJ, the high-fidelity two-qubit phase gate can be implemented with two spin ensembles within an operation time 0.41 ns and $\pi$ phase-swap gate can be realized within an operation time 103.11 ns with a high fidelity greater than 99%.