Clean and Tunable Phase Slip Qubit
Abstract
Quantum phase slips (QPS) describe coherent tunnelling of flux quanta through a narrow superconducting wire. This phenomenon is dual to one in a Josephson junction where charge carriers tunnel through a thin insulator. Since theoretical prediction of QPS, their potential to demonstrate new physics and for new applications has been widely recognized. However, unlike Josephson junctions, QPS remained unconfirmed experimentally for a long time and were observed only recently. Unfortunately, the first results showed large disorder in parameters and poor coherence raising concerns if QPS can ever offer practical advantage over Josephson devices. To enable QPS one needs to create a nanowire with very low critical currents. A conventional approach to achieve this condition is fabrication of ultra-thin wires out of highly disordered materials, a process prone to fabrication imperfections and strong impact of interface disorder. Recent experiments by demonstrated that the critical current of superconducting nanowires can be gated by external electric fields (aka “superconducting field effect�). As a result, the nanowires do not have to be ultra-thin and can be fabricated out of conventional superconductors. In this project we will explore if this mechanism of suppressing critical currents provides a new tool for engineering QPS. We will fabricate a superconducting loop with an incorporated nanowire and couple it to a superconducting microwave resonator. By measuring transmission through the resonator as a function of electric field on the gate we will be able to gain insight into physics and determine the existence of QPS in the nanowire. If QPS is confirmed, our device will work as tuneable QPS qubit opening avenues to new qubit designs and revolutionary quantum devices.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 16, 2022
- Source ID
- FA23862110087
Entities
People
- Arkady Fedorov
Organizations
- Air Force Office of Scientific Research
- Queensland University of Technology
- United States Air Force