Superconducting Circuitry for Quantum Electromechanical Systems

TL;DR

This paper reviews the evolution of superconducting circuitry in quantum electromechanical systems, highlighting recent developments in integrating superconducting qubits with mechanical elements to explore quantum motion.

Contribution

It introduces a specific QEMS design using Cooper-pair boxes and coplanar waveguide cavities, advancing the study of quantum properties of motion in engineered systems.

Findings

Development of a superconducting QEMS with CPB and CPW cavities

Potential for testing quantum properties of motion

Historical overview of superconducting systems in mechanical sensing

Abstract

Superconducting systems have a long history of use in experiments that push the frontiers of mechanical sensing. This includes both applied and fundamental research, which at present day ranges from quantum computing research and efforts to explore Planck-scale physics to fundamental studies on the nature of motion and the quantum limits on our ability to measure it. In this paper, we first provide a short history of the role of superconducting circuitry and devices in mechanical sensing, focusing primarily on efforts in the last decade to push the study of quantum mechanics to include motion on the scale of human-made structures. This background sets the stage for the remainder of the paper, which focuses on the development of quantum electromechanical systems (QEMS) that incorporate superconducting quantum bits (qubits), superconducting transmission line resonators and flexural nanomechanical elements. In addition to providing the motivation and relevant background on the physical behavior of these systems, we discuss our recent efforts to develop a particular type of QEMS that is based upon the Cooper-pair box (CPB) and superconducting coplanar waveguide (CPW) cavities, a system which has the potential to serve as a testbed for studying the quantum properties of motion in engineered systems.