arrow
Return

Characterization of Nb films for superconducting qubits using phase boundary measurements

delete2022-11-14
delete4
delete
OA
AI
K
Kevin M. Ryan
C
Carlos G. Torres‐Castanedo
D
Dominic P. Goronzy
D
David A. Garcia Wetten
M
Mark Field
C
Cameron Kopas
J
Jayss Marshall
M
Matthew J. Reagor
M
Michael J. Bedzyk
M
Mark C. Hersam
V
Venkat Chandrasekhar *
DOI:10.1063/5.0119932delete
deleteOriginal
deleteOriginal request for help
deleteShare
deleteSave
Abstract

Abstract

En 中文
Continued advances in superconducting qubit performance require more detailed understandings of the many sources of decoherence. Within these devices, two-level systems arise due to defects, interfaces, and grain boundaries and are thought to be a major source of qubit decoherence at millikelvin temperatures. In addition to Al, Nb is a commonly used metallization layer in superconducting qubits. Consequently, a significant effort is required to develop and qualify processes that mitigate defects in Nb films. As the fabrication of complete superconducting qubits and their characterization at millikelvin temperatures is a time and resource intensive process, it is desirable to have measurement tools that can rapidly characterize the properties of films and evaluate different treatments. Here, we show that measurements of the variation of the superconducting critical temperature T-c with an applied external magnetic field H (of the phase boundary T- c - H) performed with very high-resolution show features that are directly correlated with the structure of the Nb films. In combination with x-ray diffraction measurements, we show that one can even distinguish variations in the size and crystal orientation of the grains in a Nb film by small but reproducible changes in the measured superconducting phase boundary. Published under an exclusive license by AIP Publishing.
Keywords:
NIOBIUM
FIELD

Journal

Applied Physics Letters cover
Applied Physics Letters
IF:
3.6
Papers:
10.4W
Citations:
17.8W

Organization

N
Northwestern University
Scholars:
6.1W
Papers: 5.2W
Citations: 3.9K