Invited Paper MN+QS-TuA9
Superconducting Resonators as Diagnostics for Qubit Fabrication

Tuesday, October 22, 2019, 5:00 pm, Room A210

Quantum bits (qubits) fashioned from superconducting thin films and Josephson junctions

require different fabrication approaches than back-end-of-the-line semiconductor fab. This

point is driven home most clearly by the realization that the qubit as an anharmonic singlephoton

microwave resonator. The presence of single photon in the qubit represents a one, the

absence represents a zero, thus if the photon is lost, the quantum state is also lost. In

consequence, fabricators of qubits go to extremes to provide low microwave loss environments

for their qubits. Planar microwave resonators—of the multiphoton variety—are an invaluable

diagnostic tool for assessing loss mechanisms in qubit fabrication and the quality of processes

used. This presentation will give a general overview of superconducting qubits and fabrication

techniques and how microwave resonators improve qubits.

Supported by the Laboratory Directed Research and Development program at Sandia National

Laboratories, a multi-mission laboratory managed and operated by National Technology and

Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International,

Inc., for the U.S. Department of Energy's National Nuclear Security Administration under

contract DE-NA-0003525.