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Full-Text Articles in Physical Sciences and Mathematics
Approaching Quantum-Limited Electrometry In The Single-Photon Regime, Sisira Kanhirathingal
Approaching Quantum-Limited Electrometry In The Single-Photon Regime, Sisira Kanhirathingal
Dartmouth College Ph.D Dissertations
Mesoscopic quantum systems currently serve as essential building blocks in many quantum information and metrology devices. This thesis investigates the potential of quantum-limited detection in a mesoscopic electrometer named the cavity-embedded Cooper pair transistor (cCPT). As one application, this charge detector can act as the basis for an optomechanical system in the single-photon strong coupling regime. The realization of this scheme would entail near quantum-limited, ultra-sensitive electrometry at the single-photon level, the feasibility of which is studied at length in this thesis.
On the one hand, we approach this question using a fundamental, first-principles study, where an operator scattering model …
The Cavity-Embedded Cooper Pair Transistor As A Charge Detector Operating In The Nonlinear Regime, Bhargava Thyagarajan
The Cavity-Embedded Cooper Pair Transistor As A Charge Detector Operating In The Nonlinear Regime, Bhargava Thyagarajan
Dartmouth College Ph.D Dissertations
The cavity-embedded Cooper pair transistor (cCPT) has been shown to be a nearly quantum limited charge detector operating with only a single intracavity photon. Here, we use the inherent Kerr nonlinearity to demonstrate a dispersive charge sensing technique inspired by the Josephson bifurcation amplifier. Operating in the bistable regime close to a bifurcation edge, the cCPT is sensitive to charge shifts of 0.09e in a single-shot readout scheme with a detection time of 3 μs and a detection fidelity of 94%. The readout is implemented with only ∼ 25 intracavity photons in the high oscillation amplitude state, still several orders …