Improving dc SQUID Phase Qubit Lifetimes through Increased Isolation from Bias Leads
ORAL
Abstract
The dc SQUID phase qubit has been plagued by a relatively short coherence time, T$_{2}$, and relaxation time, T$_{1}$ (tens of ns). By using a sapphire substrate and small (15 $\mu $m$^{2}$ or less) Al/AlO$_{x}$/Al junctions the performance of the qubit has improved to the point where the impedance of the bias leads is the main source of dissipation and decoherence in the device. We identify the main circuit parameters that effect the isolation (junction capacitance, loop inductance, etc.), and present designs to improve the qubits isolation from the bias leads.
*This work was funded by the Joint Quantum Institute, the Center for Nanophysics and Advanced Materials, and the Department of Defense.
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Authors
Anthony Przybysz
University of Maryland, College Park
JQI, University of Maryland
Tauno Palomaki
University of Maryland, College Park
JQI, University of Maryland
Sudeep Dutta
University of Maryland, College Park
JQI, University of Maryland
Fred Wellstood
University of Maryland, College Park
JQI, University of Maryland
Rupert Lewis
University of Maryland
JQI, University of Maryland
Hanhee Paik
JQI, University of Maryland
Hyeokshin Kwon
University of Maryland, College Park
JQI, University of Maryland
Ben Cooper
JQI, University of Maryland
Kaushik Mitra
JQI, University of Maryland
Bob Anderson
University of Maryland, College Park
Dept. of Physics \& Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD
JQI, University of Maryland
Alex Dragt
JQI, University of Maryland
Chris Lobb
University of Maryland
Center for Nanophysics and Advanced Materials, University of Maryland, College Park
Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park
