2020/01/31 by Aleksei Sharafiev, Mathieu L. Juan, Oscar Gargiulo +5
Computer Science · Physics and Astronomy · #Computational physics #Photon #Physics #Quantum #Quantum Information and Cryptography #Quantum Mechanics and Applications #Quantum and electron transport phenomena #Quantum mechanics #Qubit #Transmon #Waveguide #quant-ph
paper · pdf · doi:10.22331/q-2021-06-10-474
published as Quantum 5, 474 (2021) · 18 pages, 10 figures including appendices
openalex created_date 2021/02/01 · arxiv created 2021/06/09 · openalex publication_date 2021/06/10 · arxiv updated 2021/06/16 · openalex updated_date 2026/08/05
At the dawn of Quantum Physics, Wigner and Weisskopf obtained a full analytical description (a <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mtext class="MJX-tex-mathit" mathvariant="italic">photon portrait</mml:mtext></mml:mrow></mml:math>) of the emission of a single photon by a two-level system, using the basis of frequency modes (Weisskopf and Wigner, "Zeitschrift für Physik", 63, 1930). A direct experimental reconstruction of this portrait demands an accurate measurement of a time resolved fluorescence spectrum, with high sensitivity to the off-resonant frequencies and ultrafast dynamics describing the photon creation. In this work we demonstrate such an experimental technique in a superconducting waveguide Quantum Electrodynamics (wQED) platform, using single transmon qubit and two coupled transmon qubits as quantum emitters. In both scenarios, the photon portraits agree quantitatively with the predictions of the input-output theory and qualitatively with Wigner-Weisskopf theory. We believe that our technique allows not only for interesting visualization of fundamental principles, but may serve as a tool, e.g. to realize multi-dimensional spectroscopy in waveguide Quantum Electrodynamics.