Characterizing decoherence rates of a superconducting qubit by direct microwave scattering
Journal article, 2021

We experimentally investigate a superconducting qubit coupled to the end of an open transmission line, in a regime where the qubit decay rates to the transmission line and to its own environment are comparable. We perform measurements of coherent and incoherent scattering, on- and off-resonant fluorescence, and time-resolved dynamics to determine the decay and decoherence rates of the qubit. In particular, these measurements let us discriminate between non-radiative decay and pure dephasing. We combine and contrast results across all methods and find consistent values for the extracted rates. The results show that the pure dephasing rate is one order of magnitude smaller than the non-radiative decay rate for our qubit. Our results indicate a pathway to benchmark decoherence rates of superconducting qubits in a resonator-free setting.

Author

Yong Lu

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Andreas Bengtsson

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Jonathan Burnett

National Physical Laboratory (NPL)

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Emely Wiegand

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Baladitya Suri

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Indian Institute of Science

Philip Krantz

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Device Physics

Anita Fadavi Roudsari

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Anton Frisk Kockum

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Simone Gasparinetti

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

Göran Johansson

Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics

Per Delsing

Chalmers, Microtechnology and Nanoscience (MC2), Quantum Technology

npj Quantum Information

20566387 (eISSN)

Vol. 7 1 35

Subject Categories

Telecommunications

Atom and Molecular Physics and Optics

Other Physics Topics

DOI

10.1038/s41534-021-00367-5

More information

Latest update

3/3/2021 1