Rotating-frame relaxation as a noise spectrum analyser of a superconducting qubit undergoing driven evolution
Journal article, 2013

Gate operations in a quantum information processor are generally realized by tailoring specific periods of free and driven evolution of a quantum system. Unwanted environmental noise, which may in principle be distinct during these two periods, acts to decohere the system and increase the gate error rate. Although there has been significant progress characterizing noise processes during free evolution, the corresponding driven-evolution case is more challenging as the noise being probed is also extant during the characterization protocol. Here we demonstrate the noise spectroscopy (0.1-200 MHz) of a superconducting flux qubit during driven evolution by using a robust spin-locking pulse sequence to measure relaxation (T1ρ) in the rotating frame. In the case of flux noise, we resolve spectral features due to coherent fluctuators, and further identify a signature of the 1 MHz defect in a time-domain spin-echo experiment. The driven-evolution noise spectroscopy complements free-evolution methods, enabling the means to characterize and distinguish various noise processes relevant for universal quantum control. © 2013 Macmillan Publishers Limited. All rights reserved.

Author

F. Yan

Massachusetts Institute of Technology (MIT)

S. Gustavsson

Massachusetts Institute of Technology (MIT)

Jonas Bylander

Massachusetts Institute of Technology (MIT)

X. Jin

Massachusetts Institute of Technology (MIT)

F. Yoshihara

RIKEN

D.G. Cory

University of Tokyo

Massachusetts Institute of Technology (MIT)

Y. Nakamura

RIKEN

University of Tokyo

T.P. Orlando

Massachusetts Institute of Technology (MIT)

W.D. Oliver

Massachusetts Institute of Technology (MIT)

Nature Communications

2041-1723 (ISSN) 20411723 (eISSN)

Vol. 4 2337-

Subject Categories

Atom and Molecular Physics and Optics

Nano Technology

Condensed Matter Physics

DOI

10.1038/ncomms3337

More information

Latest update

8/12/2022