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arXiv · 0906.4362

Photodetection of propagating quantum microwaves in circuit QED

G. Romero·J. J. Garcia-Ripoll·E. Solano
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Abstract

We develop the theory of a metamaterial composed of an array of discrete quantum absorbers inside a one-dimensional waveguide that implements a high-efficiency microwave photon detector. A basic design consists of a few metastable superconducting nanocircuits spread inside and coupled to a one-dimensional waveguide in a circuit QED setup. The arrival of a {\it propagating} quantum microwave field induces an irreversible change in the population of the internal levels of the absorbers, due to a selective absorption of photon excitations. This design is studied using a formal but simple quantum field theory, which allows us to evaluate the single-photon absorption efficiency for one and many absorber setups. As an example, we consider a particular design that combines a coplanar coaxial waveguide with superconducting phase qubits, a natural but not exclusive playground for experimental implementations. This work and a possible experimental realization may stimulate the possible arrival of "all-optical" quantum information processing with propagating quantum microwaves, where a microwave photodetector could play a key role.

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G. Romero, J. J. Garcia-Ripoll, E. Solano. 2009-06-23. Photodetection of propagating quantum microwaves in circuit QED. https://doi.org/10.1088/0031-8949%2F2009%2Ft137%2F014004

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