Few-mode to mesoscopic junctions in gatemon qubits

Abstract

We investigate a semiconductor nanowire-based gatemon qubit with epitaxial Al on two facets of the nanowire, allowing gate control of wire density. Two segments have the Al removed, one forming a Josephson junction and the other operating as a transistor, providing in-situ switching between dc transport and qubit operation. Gating the NW changes the bulk wire potential distribution, while gating the Josephson junction changes the number of junction modes. Both effects are revealed by the dependence of qubit frequency on parallel magnetic field. A detailed model of the wire and junction yields behavior consistent with experiment. In the multi-mode regime, fluctuations in qubit frequency are considerably smaller than the theoretical "universal" value, also smaller than numerics, and consistent with previous measurements of fluctuating critical current.

References in corpus (10)

• Epitaxy of Semiconductor-Superconductor nanowires
• Tunable Supercurrent Through Semiconductor Nanowires
• Coherent manipulation of an Andreev spin qubit
• Supercurrent interference in few-mode nanowire Josephson junctions
• Signatures of interactions in the Andreev spectrum of nanowire Josephson junctions
• Magnetic-Field-Compatible Superconducting Transmon Qubit
• Gate-tunable kinetic inductance in proximitized nanowires
• Full parity phase diagram of a proximitized nanowire island
• Controlled DC Monitoring of a Superconducting Qubit
• Andreev Modes from Phase Winding in a Full-shell Nanowire-based Transmon

Cited by in corpus (5)

• Direct microwave spectroscopy of Andreev bound states in planar Ge Josephson junctions
• Gatemonium: A Voltage-Tunable Fluxonium
• Microwave Andreev bound state spectroscopy in a semiconductor-based Planar Josephson junction
• Gatemon Qubit Revisited for Improved Reliability and Stability
• Strongly anharmonic flux-tunable transmon based on InAs-Al 2D heterostructure