Fabrication Technology of and Symmetry Breaking in Superconducting Quantum Circuits

TL;DR

This paper details the fabrication and characterization of superconducting quantum circuits, exploring their symmetry properties, tunability, and energy shifts, advancing their application in quantum information processing and fundamental tests of quantum mechanics.

Contribution

It introduces new fabrication techniques and analyzes symmetry breaking and energy shifts in superconducting qubits, providing insights into their control and fundamental properties.

Findings

Successful fabrication of superconducting flux qubits and resonators

Analysis of symmetry breaking and energy shifts in qubits

Derivation of matrix elements for microwave-driven transitions

Abstract

Superconducting quantum circuits are promising systems for experiments testing fundamental quantum mechanics on a macroscopic scale and for applications in quantum information processing. We report on the fabrication and characterization of superconducting flux qubits, readout dc SQUIDs, on-chip shunting capacitors, and high-quality coplanar waveguide resonators. Furthermore, we discuss the tunability and fundamental symmetry aspects inherent to all superconducting qubits, which can be regarded as artificial solid-state atoms. Comparing them to their natural counterparts, we discuss first and second-order energy shifts due to static control fields. Additionally, we present an intuitive derivation of the first- and second-order matrix elements for level transitions in the presence of a coherent microwave driving.