Pulse Current Measurements and Rabi Oscillations in a dc SQUID Phase Qubit

Author

Palomaki, T.A. ; Dutta, S.K. ; Lewis, R.M. ; Paik, H.. ; Mitra, K. ; Cooper, B.K. ; Przybysz, A.J. ; Dragt, A.J. ; Anderson, J.R. ; Lobb, C.J. ; Wellstood, F.C.

Author_Institution

Maryland Univ., College Park

Volume

17

Issue

2

fYear

2007

fDate

6/1/2007 12:00:00 AM

Firstpage

162

Lastpage

165

Abstract

We have used 2 ns pulses of current to read out the states of a Nb/AlO_x/Nb dc SQUID phase qubit at 25 mK. Plotting the number of escape events that occur versus the size of the current pulse reveals a series of steps corresponding to the occupancy of different energy levels. After calibrating the measurement pulses, we fit these steps to determine the population in each level. Rabi oscillations were viewed using this technique. The single-shot measurement fidelity was theoretically analysed and the optimal single pulse in our device was determined.

Keywords

SQUIDs; aluminium compounds; energy states; niobium; pulse measurement; Nb-AlO-Nb - Interface; Rabi oscillations; calibration; current pulse; dc SQUID phase qubit; energy levels; escape events; optimal single pulse; pulse current measurements; single shot measurement fidelity; time 2 ns; Current measurement; Energy states; Inductors; Niobium; Phase measurement; Pulse measurements; Quantum computing; SQUIDs; Switches; Voltage; Josephson junction; pulsed-readout; qubit;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2007.898561

Filename

4277655