Multiphoton Quantum Logic Gates for Superconducting Resonators with Tunable Nonlinear Interaction

TL;DR

This paper introduces a tunable nonlinear interaction mediated by a transmon qubit for implementing high-fidelity quantum logic gates on superconducting resonators, enabling fast and reliable quantum operations with multiphoton states.

Contribution

It proposes a new tunable nonlinear interaction scheme for superconducting resonators mediated by a transmon qubit, facilitating high-fidelity quantum logic gates.

Findings

Operations can be performed with near-unit fidelity without dissipation.

Two-photon two-resonator operations achieve 99.9% fidelity with decoherence.

The system can be implemented with existing microwave technology.

Abstract

We propose a tunable nonlinear interaction for the implementation of quantum logic operations on pairs of superconducting resonators, where the two-resonator interaction is mediated by a transmon quantum bit (qubit). This interaction is characterized by a high on-to-off coupling ratio and allows for fast qubit-type and $d$-level system (qudit)-type operations for quantum information processing with multiphoton cavity states. We present analytical and numerical calculations showing that these operations can be performed with practically unit fidelity in absence of any dissipative phenomena, whereas physical two-photon two-resonator operations can be realized with a fidelity of 99.9% in presence of qubit and resonator decoherence. The resonator-qubit-resonator system proposed in this Letter can be implemented using available planar or three-dimensional microwave technology.