6 papers
Oxide-nitride heteroepitaxy for low-loss dielectrics in superconducting quantum circuits
David A. Garcia-Wetten, Mitchell J. Walker, Peter G. Lim +9
Superconducting qubits show great promise for the realization of fault-tolerant quantum computing, but lossy, amorphous dielectrics limit current technology. Identifying highly cry…
Effect of metal encapsulation on bulk superconducting properties of niobium thin films used in qubits
Amlan Datta, Kamal R. Joshi, Sunil Ghimire +18
Niobium metal occupies nearly 100\% of the volume of a typical 2D transmon device. While the aluminum Josephson junction is of utmost importance, maintaining quantum coherence acro…
Comparison of Nb and Ta Pentoxide Loss Tangents for Superconducting Quantum Devices
D. P. Goronzy, W. W. Mah, P. G. Lim +14
Superconducting transmon qubits are commonly made with thin-film Nb wiring, but recent studies have shown increased performance with Ta wiring. In this work, we compare the resonat…
Identifying Materials-Level Sources of Performance Variation in Superconducting Transmon Qubits
Akshay A. Murthy, Mustafa Bal, Michael J. Bedzyk +46
The Superconducting Materials and Systems (SQMS) Center, a DOE National Quantum Information Science Research Center, has conducted a comprehensive and coordinated study using super…
X-ray scattering investigation of hydride surface segregation in epitaxial Nb films
David A. Garcia-Wetten, Philip J. Ryan, Jong Woo Kim +4
Hydride precipitation in niobium-based, superconducting circuits is a damaging side-effect of hydrofluoric acid treatments used to clean and thin the Nb surface oxides and Si oxide…
Loss tangent fluctuations due to two-level systems in superconducting microwave resonators
André Vallières, Megan E. Russell, Xinyuan You +10
Superconducting microwave resonators are critical to quantum computing and sensing technologies. Additionally, they are common proxies for superconducting qubits when determining t…