Io-Chun Hoi received B.S. and Ph.D. in Electro-Physics Department, National Chiao Tung University, Taiwan and Department of Microtechnology and Nanoscience, Chalmers University of Technology, Sweden, respectively. He did his postdoctoral research at University of California, Santa Barbara, U.S.A. He was an assistant professor and associate professor at National Tsing Hua University, Taiwan. He is currently associate professor at Physics department, City University of Hong Kong. He is the author or co-author of 24 publications, including 3 first-authored Physical Review Letters, 1 first-authored Nature Physics and 2 corresponding-authored Physical Review Letters and 1 corresponding-authored Nano Letters.
Loading quantum information deterministically onto a quantum node is an important step towards 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 contained in the pulse N < < 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% from 1D semi-free 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%. We also theoretically show that Fock-state microwave photons can be deterministically loaded with an efficiency of 98.5% due to an overlap of 99.3% between input and time-reversed emission. Our results open up promising applications in realizing quantum networks based on waveguide quantum electrodynamics.