Quantum state transfer and controlled-phase gate on one-dimensional superconducting resonators assisted by a quantum bus

TL;DR

This paper proposes a scalable quantum processor using superconducting resonators and a quantum bus, enabling high-fidelity quantum state transfer and controlled-phase gates for microwave photons, advancing quantum communication and computation.

Contribution

It introduces a novel architecture with tunable couplings via SQUIDs, demonstrating effective quantum state transfer and gate operations on distant resonators.

Findings

High-fidelity quantum state transfer demonstrated

Implementation of controlled-phase gate between distant resonators

Potential applications in quantum communication

Abstract

We propose a quantum processor for the scalable quantum computation on microwave photons in distant one-dimensional superconducting resonators. It is composed of a common resonator R acting as a quantum bus and some distant resonators $r_j$ coupled to the bus in different positions assisted by superconducting quantum interferometer devices (SQUID), different from previous processors. R is coupled to one transmon qutrit, and the coupling strengths between $r_j$ and R can be fully tuned by the external flux through the SQUID. To show the processor can be used to achieve universal quantum computation effectively, we present a scheme to complete the high-fidelity quantum state transfer between two distant microwave-photon resonators and another one for the high-fidelity controlled-phase gate on them. By using the technique for catching and releasing the microwave photons from resonators, our processor may play an important role in quantum communication as well.