activity
20222024
most citedSystematic Improvements in Transmon Qubit Coherence Enabled by Niobium Surface Encapsulation

123 citations · 179 across the 7 of their papers we have counts for

collaborators

7 papers

cond-mat.mtrl-sci2024★ 6 cited

Enhanced Superconducting Qubit Performance Through Ammonium Fluoride Etch

Cameron J. Kopas, Dominic P. Goronzy, Thang Pham +19

The performance of superconducting qubits is often limited by dissipation and two-level systems (TLS) losses. The dominant sources of these losses are believed to originate from am…

physics.app-ph2024★ 23 cited

Alternating Bias Assisted Annealing of Amorphous Oxide Tunnel Junctions

David P. Pappas, Mark Field, Cameron Kopas +10

We demonstrate a transformational technique for controllably tuning the electrical properties of fabricated thermally oxidized amorphous aluminum-oxide tunnel junctions. Using conv…

quant-ph2023★ 123 cited

Systematic Improvements in Transmon Qubit Coherence Enabled by Niobium Surface Encapsulation

Mustafa Bal, Akshay A. Murthy, Shaojiang Zhu +37

We present a novel transmon qubit fabrication technique that yields systematic improvements in T relaxation times. We fabricate devices using an encapsulation strategy that inv…

cond-mat.mtrl-sci2022

Understanding the Mechanism of the Performance Improvement in Nitrogen-doped Niobium Superconducting Radio Frequency Cavity

Xiaotian Fang, Jin-Su Oh, Matt Kramer +4

Niobium superconducting radiofrequency cavities enable applications in modern accelerators and quantum computers. However, the surface resistance significantly deteriorates the cav…

cond-mat.supr-con2022★ 14 cited

Quasiparticle spectroscopy, transport, and magnetic properties of Nb films used in superconducting transmon qubits

Kamal R. Joshi, Sunil Ghimire, Makariy A. Tanatar +10

Niobium thin films on silicon substrate used in the fabrication of superconducting qubits have been characterized using scanning and transmission electron microscopy, electrical tr…

cond-mat.mes-hall2022★ 13 cited

Visualizing heterogeneous dipole fields by terahertz light coupling in individual nano-junctions used in transmon qubits

R. H. J. Kim, J. M. Park, S. Haeuser +12

The fundamental challenge underlying superconducting quantum computing is to characterize heterogeneity and disorder in the underlying quantum circuits. These nonuniform distributi…

cond-mat.mes-hall2022

Developing a Chemical and Structural Understanding of the Surface Oxide in a Niobium Superconducting Qubit

Akshay A. Murthy, Paul Masih Das, Stephanie M. Ribet +11

Superconducting thin films of niobium have been extensively employed in transmon qubit architectures. Although these architectures have demonstrated remarkable improvements in rece…