biostudies-literatureLin WJNippon Telegraph and Telephone CorporationNational Science and Technology Council, TaiwanNational Taiwan UniversityFoundational Questions InstituteAsian Office of Aerospace Research and DevelopmentCity University of Hong KongKnut och Alice Wallenbergs StiftelseMinistry of Science and Technology, TaiwanMinistry of EducationArmy Research OfficeJapan Science and Technology AgencyVetenskapsr?detJapan Society for the Promotion of Science8137-8142https://www.ebi.ac.uk/biostudies/studies/S-EPMC9615994biostudies-literatureUnknown22(20)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 (<i>N</i>) 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% ± 0Nano lettersDeterministic Loading of Microwaves onto an Artificial Atom Using a Time-Reversed Waveform.PMC9615994JPMJMS2061FA2386-20-1-4069JP20H00134109-2636-M-007-0072015-00152FQXi-IAF19-06109-2112-M-002- 022NTU-CC-110L8901062019- 03696W911NF-18-1-03589610569110-2112-M-194-006-MY3Lin JJLu YLin GDLin WJLee CPCheng YTChen JCHoi ICLin KTChiang KHChen CYLin YHChuu CSNori FDelsing PHsieh MCChien CHFrisk Kockum AWen PYfalseDeterministic Loading of Microwaves onto an Artificial Atom Using a Time-Reversed Waveform.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 (<i>N</i>) 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% ± 02022-01-01T00:00:00Z2022 Oct2025-04-19T07:14:04.575Z2025-04-19T07:14:04.575ZS-EPMC96159943620098610.1021/acs.nanolett.2c02578