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arXiv · 2010.11392

Ground-state Pulsed Cavity Electro-optics for Microwave-to-optical Conversion

Wei Fu·Mingrui Xu·Xianwen Liu·Chang-Ling Zou·Changchun Zhong·Xu Han·Mohan Shen·Yuntao Xu·Risheng Cheng·Sihao Wang·Liang Jiang·Hong X. Tang
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Abstract

In the development of quantum microwave-to-optical (MO) converters, excessive noise induced by the parametric optical drive remains a major challenge at milli-Kelvin temperatures. Here we study the extraneous noise added to an electro-optic transducer in its quantum ground state under an intense pulsed optical excitation. The integrated electro-optical transducer leverages the inherent Pockels effect of aluminum nitride microrings, flip-chip bonded to a superconducting resonator. Applying a pulsed optical drive with peak power exceeding the cooling power of the dilution refrigerator at its base temperature, we observe efficient bi-directional MO conversion, with near-ground state microwave thermal excitation ($\bar{n}_\mathrm{e}=0.09\pm0.06$). Time evolution study reveals that the residual thermal excitation is dominated by the superconductor absorption of stray light scattered off the chip-fiber interface. Our results shed light on suppressing microwave noise in a cavity electro-optic system under intense optical drive, which is an essential step towards quantum state transduction between microwave and optical frequencies.

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Wei Fu, Mingrui Xu, Xianwen Liu, Chang-Ling Zou, Changchun Zhong, Xu Han, Mohan Shen, Yuntao Xu, Risheng Cheng, Sihao Wang, Liang Jiang, Hong X. Tang. 2020-10-22. Ground-state Pulsed Cavity Electro-optics for Microwave-to-optical Conversion. https://doi.org/10.1103/physreva.103.053504

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