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arXiv · 1509.06154

Higher order non-linear effects in a Josephson parametric amplifier

Bogdan A. Kochetov·Arkady Fedorov
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Abstract

Non-linearity of the current-phase relationship of a Josephson junction is the key resource for a Josephson parametric amplifier (JPA), the only device in which the quantum limit has so far been achieved at microwave frequencies. A standard approach to describe JPA takes into account only the lowest order (cubic) non-linearity resulting in a Duffing-like oscillator equation of motion or in a Kerr-type non-linearity term in the Hamiltonian. In this paper we derive the quantum expression for the gain of JPA including all orders of the Josephson junction non-linearity in the linear response regime. We then analyse gain saturation effect for stronger signals within semi-classical approach. Our results reveal non-linear effects of higher orders and their implications for operation of a JPA.

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Bogdan A. Kochetov, Arkady Fedorov. 2015-09-21. Higher order non-linear effects in a Josephson parametric amplifier. https://doi.org/10.1103/physrevb.92.224304

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