DocumentCode :
112391
Title :
DC SQUID Phase Qubit Coupled to an On-Chip LC Resonator
Author :
Budoyo, R.P. ; Cooper, B.K. ; Zaretskey, V. ; Ballard, Cody J ; Anderson, J.R. ; Lobb, C.J. ; Wellstood, F.C.
Author_Institution :
Dept. of Phys., Univ. of Maryland, College Park, MD, USA
Volume :
23
Issue :
3
fYear :
2013
fDate :
Jun-13
Firstpage :
1701504
Lastpage :
1701504
Abstract :
We have fabricated and tested an Al/AlOx/Al dc SQUID phase qubit on a sapphire substrate with a qubit junction area 0.17 μm2 and critical current I0,J1 = 1.4 μA. The qubit is shunted by an interdigitated capacitor and isolated from the bias leads by an inductive isolation network using a larger Josephson junction with area 2 μm2 and critical current I0,J2 = 29 μA. Additional high-frequency filtering is provided by an on-chip LC filter, which consists of square spiral inductors and parallel plate SiNx capacitors. From detuned Rabi oscillation measurements, we estimate a relaxation time T1 ≈ 400 ns and dephasing time TΦ 1700 ns. Additionally, we observe that the qubit transition spectrum has multiple equally spaced subpeaks. These subpeaks are caused by coupling between the phase qubit and the LC filter, forming a Jaynes-Cummings system. Each individual subpeak corresponds to transitions with different photon numbers in the LC filter.
Keywords :
SQUIDs; aluminium; aluminium compounds; capacitors; superconducting filters; Additional high-frequency filtering; Al-AlOx-Al; DC SQUID phase qubit junction; Jaynes-Cummings system; Josephson junction; LC filter; current 1.4 muA; current 29 muA; detuned Rabi oscillation measurements; inductive isolation network; interdigitated capacitor; on-chip LC resonator; parallel plate capacitors; qubit transition spectrum; sapphire substrate; square spiral inductors; Capacitors; Couplings; Junctions; Microwave oscillators; Photonics; SQUIDs; Jaynes-Cummings model; dc SQUID; phase qubit; superconducting quantum computing;
fLanguage :
English
Journal_Title :
Applied Superconductivity, IEEE Transactions on
Publisher :
ieee
ISSN :
1051-8223
Type :
jour
DOI :
10.1109/TASC.2013.2237876
Filename :
6403518
Link To Document :
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