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arXiv · 2103.04829

Phonon-number resolution of voltage-biased mechanical oscillators with weakly-anharmonic superconducting circuits

Mario F. Gely·Gary A. Steele
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Abstract

Observing quantum phenomena in macroscopic objects, and the potential discovery of a fundamental limit in the applicability of quantum mechanics, has been a central topic of modern experimental physics. Highly coherent and heavy micro-mechanical oscillators controlled by superconducting circuits are a promising system for this task. Here, we focus in particular on the electrostatic coupling of motion to a weakly anharmonic circuit, namely the transmon qubit. In the case of a megahertz mechanical oscillator coupled to a gigahertz transmon, we explain the difficulties in bridging the large electro-mechanical frequency gap. To remedy this issue, we explore the requirements to reach phonon-number resolution in the resonant coupling of a megahertz transmon and a mechanical oscillator.

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Mario F. Gely, Gary A. Steele. 2021-03-08. Phonon-number resolution of voltage-biased mechanical oscillators with weakly-anharmonic superconducting circuits. https://doi.org/10.1103/physreva.104.053509

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