RF-driven Josephson bifurcation amplifier for quantum measurement.
We have constructed a new type of amplifier whose primary purpose is the readout of superconducting quantum bits. It is based on the transition of a rf-driven Josephson junction between two distinct oscillation states near a dynamical bifurcation point. The main advantages of this new amplifier are speed, high sensitivity, low backaction, and the absence of on-chip dissipation. Pulsed microwave reflection measurements on nanofabricated Al junctions show that actual devices attain the performance predicted by theory.
Siddiqi
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Departments of Applied Physics and Physics, Yale University, New Haven, Connecticut 06520-8284, USA.
Vijay
R
R
Pierre
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F
Wilson
C M
CM
Metcalfe
M
M
Rigetti
C
C
Frunzio
L
L
Devoret
M H
MH