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arXiv · 2209.05165

Overcoming photon blockade in circuit QED single-atom maser with engineered metastability and strong coupling

A. A. Sokolova·D. A. Kalacheva·G. P. Fedorov·O. V. Astafiev
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Abstract

Reaching high cavity population with a coherent pump in the strong-coupling regime of a single-atom laser is impossible due to the photon blockade effect. In this work, we experimentally demonstrate that in a single-atom maser based on a transmon strongly coupled to two resonators it is possible to pump over a dozen of photons into the system. The first high-quality resonator plays a role of usual lasing cavity, and the second one presents a controlled dissipation channel, bolstering population inversion, and modifies the energy level structure to lift the blockade. As a confirmation of lasing action, we observe conventional laser features such as the narrowing of emission linewidth and external signal amplification. Additionally, we report unique single-atom features: self-quenching and several lasing thresholds.

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A. A. Sokolova, D. A. Kalacheva, G. P. Fedorov, O. V. Astafiev. 2022-09-12. Overcoming photon blockade in circuit QED single-atom maser with engineered metastability and strong coupling. https://doi.org/10.1103/physreva.107.l031701

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