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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-3744
DTSTART:20151022T150000Z
DURATION:PT1H0M0S
DTSTAMP:20240329T055940Z
LAST-MODIFIED:20151012T165455Z
LOCATION:5310 Chamberlin Hall
SUMMARY:Programmable nonreciprocity in multi-mode parametric devices\,
R. G. Herb Condensed Matter Seminar\, Dr. Leonardo Ranzani\, BBN/Rayt
heon
DESCRIPTION:
\nJosephson Parametric Amplifiers (JPAs) can perform
quantum-limited
\nreadout of superconducting qubits. However\, sin
ce they are
\nreflection-based amplifiers\, an external RF circula
tor is always
\nnecessary to suppress back-action. A new approach
is to use directional
\nparametric amplification by driving multip
le parametric processes
\nsimultaneously with different pump phase
s. SQUID and SLUG amplifiers in
\nfact operate by a similar mechan
ism: the interference between parametric
\nprocesses driven by int
ernal oscillations at the Josephson frequency
\nsuppresses the rev
erse gain and explains the high level of isolation in
\nthis devic
es. In this talk I am going to discuss a general approach to
\nthe
study of parametric devices driven by multiple pump signals. As
\
nopposed to traditional JPAs\, where only two modes\, signal and idler
\,
\ninteract\, in multi-pump devices three or more modes are pump
ed
\nsimultaneously. I will show how to use directed graphs to com
pute the
\nscattering properties of such multi-mode devices and de
sign parametric
\nnonreciprocal components\, including circulators
and directional amplifiers.
URL:https://www.physics.wisc.edu/events/?id=3744
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