699 research outputs found
Nonreciprocal Photon Transmission and Amplification via Reservoir Engineering
We discuss a general method for constructing nonreciprocal, cavity-based
photonic devices, based on matching a given coherent interaction with its
corresponding dissipative counterpart; our method generalizes the basic
structure used in the theory of cascaded quantum systems, and can render an
extremely wide class of interactions directional. In contrast to standard
interference-based schemes, our approach allows directional behavior over a
wide bandwidth. We show how it can be used to devise isolators and directional,
quantum-limited amplifiers. We discuss in detail how this general method allows
the construction of a directional, noise-free phase-sensitive amplifier that is
not limited by any fundamental gain-bandwidth constraint. Our approach is
particularly well-suited to implementations using superconducting microwave
circuits and optomechanical systems.Comment: 15 pages, 6 figure
Non-degenerate, three-wave mixing with the Josephson ring modulator
The Josephson ring modulator (JRM) is a device, based on Josephson tunnel
junctions, capable of performing non-degenerate mixing in the microwave regime
without losses. The generic scattering matrix of the device is calculated by
solving coupled quantum Langevin equations. Its form shows that the device can
achieve quantum-limited noise performance both as an amplifier and a mixer.
Fundamental limitations on simultaneous optimization of performance metrics
like gain, bandwidth and dynamic range (including the effect of pump depletion)
are discussed. We also present three possible integrations of the JRM as the
active medium in a different electromagnetic environment. The resulting
circuits, named Josephson parametric converters (JPC), are discussed in detail,
and experimental data on their dynamic range are found to be in good agreement
with theoretical predictions. We also discuss future prospects and requisite
optimization of JPC as a preamplifier for qubit readout applications.Comment: 21 pages, 16 figures, 4 table
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