Transferring arbitrary d-dimensional quantum states of a superconducting qudit in circuit QED

TL;DR

This paper presents a fast, high-fidelity method for transferring arbitrary quantum states between two superconducting qudits in circuit QED, using resonant interactions without measurement, applicable to various quantum systems.

Contribution

It introduces a novel resonant interaction-based protocol for deterministic quantum state transfer between superconducting qudits, improving speed and fidelity over previous methods.

Findings

High-fidelity transfer feasible with current technology

Applicable to qudits with dimension up to 5

Method is general for various quantum systems

Abstract

A qudit ($d$-level quantum systems) has a large Hilbert space and thus can be used to achieve many quantum information and communication tasks. Here, we propose a method to transfer arbitrary $d$-dimensional quantum states (known or unknown) between two superconducting qudits coupled to a single cavity. The state transfer can be performed fast because of employing resonant interactions only. In addition, quantum states can be deterministically transferred without measurement. Numerical simulations show that high-fidelity transfer of quantum states between two superconducting transmon qudits ($d\leq5$) is feasible with current circuit QED technology. This proposal is quite general and can be applied to accomplish the same task with various superconducting qudits, quantum dots, or natural atoms coupled to a cavity or resonator.