Quantum State Transmission in a Superconducting Charge Qubit-Atom Hybrid

TL;DR

This paper proposes a hybrid quantum system combining a neutral-atom qubit with a superconducting charge qubit, enabling state transfer between microscopic and macroscopic quantum components for advanced quantum information processing.

Contribution

It introduces a novel hybrid structure with direct atom-superconductor interface and demonstrates a method for quantum state transfer using spectroscopic techniques and gate voltage control.

Findings

Successful theoretical model for state transfer between atom and superconductor.

Identification of Stark shift dependence on charge-qubit states.

Potential for high-speed quantum information operations.

Abstract

Hybrids consisting of macroscopic superconducting circuits and microscopic components, such as atoms and spins, have the potential of transmitting an arbitrary state between different quantum species, leading to the prospective of high-speed operation and long-time storage of quantum information. Here we propose a novel hybrid structure, where a neutral-atom qubit directly interfaces with a superconducting charge qubit, to implement the qubit-state transmission. The highly-excited Rydberg atom located inside the gate capacitor strongly affects the behavior of Cooper pairs in the box while the atom in the ground state hardly interferes with the superconducting device. In addition, the DC Stark shift of the atomic states significantly depends on the charge-qubit states. By means of the standard spectroscopic techniques and sweeping the gate voltage bias, we show how to transfer an arbitrary quantum state from the superconducting device to the atom and vice versa.