Deterministic Loading of Microwaves onto an Artificial Atom Using a Time-Reversed Waveform

Wei-Ju Lin, Yong Lu, Ping-Yi Wen, Yu-Ting Cheng, Ching-Ping Lee, Kuan Ting Lin, Kuan Hsun Chiang, Ming Che Hsieh, Ching-Yeh Chen, Chin-Hsun Chien, Jia Jhan Lin, Jeng-Chung Chen, Yen Hsiang Lin, Chih-Sung Chuu, Franco Nori, Anton Frisk Kockum, Guin Dar Lin, Per Delsing and Io-Chun Hoi

Nano Lett. 2022, 22, 20, 8137–8142 – Published in October 2022


Loading quantum information deterministically onto a quantum node is an important step toward a quantum network. Here, we demonstrate that coherent-state microwave photons with an optimal temporal waveform can be efficiently loaded onto a single superconducting artificial atom in a semi-infinite one-dimensional (1D) transmission-line waveguide. Using a weak coherent state (the number of photons (N) contained in the pulse ≪1) with an exponentially rising waveform, whose time constant matches the decoherence time of the artificial atom, we demonstrate a loading efficiency of 94.2% ± 0.7% from 1D semifree space to the artificial atom. The high loading efficiency is due to time-reversal symmetry: the overlap between the incoming wave and the time-reversed emitted wave is up to 97.1% ± 0.4%. Our results open up promising applications in realizing quantum networks based on waveguide quantum electrodynamics.