LC Filtered dc SQUID Phase Qubit with Low Dielectric Loss
ORAL
Abstract
We have investigated a dc SQUID phase qubit with LC filter, which has a relatively small ($\sim $4 $\mu $m$^{2})$ Al/AlO$_{x}$/Al Josephson junction shunted by an additional capacitor built using low-stress thin film SiN$_{x}$. The LC isolation provides an additional isolation factor at the junction plasma frequency and allows flexibility in the choice of SQUID parameters. We report Rabi oscillations with a 42 ns envelope decay time (T'), and a 32 ns energy relaxation time (T$_{1})$, consistent with a loss tangent of about 7 x 10$^{-4}$ in the loss-stress SiN$_{x}$. We also report on progress towards getting longer coherence times using a high-stress SiN$_{x}$ with a lower loss tangent.
*Funding provided by JQI, CNAM and the DOD
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Authors
H. Kwon
University of Maryland, College Park
University of Maryland, JQI, CNAM
Anthony Przybysz
University of Maryland, College Park
University of Maryland, JQI, CNAM
T. A. Palomaki
Charmers University
Hanhee Paik
Laboratory for Physical Sciences
Kevin Osborn
Laboratory for Physical Sciences
R. M. Lewis
Northrop Grumman Corp
B. K. Cooper
University of Maryland, College Park
J.R. Anderson
University of Maryland, College Park
University of Maryland, JQI, CNAM
Christopher Lobb
University of Maryland, College Park
University of Maryland, JQI, CNAM
Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland
F.C. Wellstood
Center for Nanophysics and Advanced Materials and Joint Quantum Institute, Physics Department, University of Maryland College Park
