Group Delay Controlled by the Decoherence of a Single Artificial Atom
Journal article, 2025
The ability to slow down light at the single-photon level has applications in quantum information processing and other quantum technologies. We demonstrate two methods, both using just a single artificial atom, enabling dynamic control over microwave light velocities in waveguide quantum electrodynamics (QED). Our methods are based on two distinct mechanisms harnessing the balance between radiative decay and nonradiative decoherence rates of a superconducting artificial atom in front of a mirror. In the first method, we tune the radiative decay of the atom using interference effects due to the mirror; in the second method, we pump the atom to effectively control its nonradiative decoherence. When the half of the radiative decay rate exceeds the nonradiative decoherence rate, we observe positive group delay; conversely, dominance of the nonradiative decoherence results in negative group delay. Our results advance signal-processing capabilities in waveguide QED.
Author
Y. -T. Cheng
City University of Hong Kong
K. -M. Hsieh
City University of Hong Kong
B. -Y. Wu
City University of Hong Kong
Z. Q. Niu
ShanghaiTech University
Chinese Academy of Sciences
F. Aziz
National Tsing Hua University
Y. -H. Huang
National Tsing Hua University
P. Y. Wen
National Chung Cheng University
K. -T. Lin
Hon Hai Research Institute
National Taiwan University
Y. -H. Lin
National Tsing Hua University
J. C. Chen
National Tsing Hua University
Anton Frisk Kockum
Chalmers, Microtechnology and Nanoscience (MC2), Applied Quantum Physics
G. -D. Lin
Hon Hai Research Institute
National Center for Theoretical Sciences (NCTS)
National Taiwan University
Z. -R. Lin
Chinese Academy of Sciences
Y. Lu
Xidian University
I. -C. Hoi
City University of Hong Kong
Physical Review Letters
0031-9007 (ISSN) 1079-7114 (eISSN)
Vol. 135 7 073601Subject Categories (SSIF 2025)
Atom and Molecular Physics and Optics
Other Physics Topics
DOI
10.1103/fkzb-fxv4
PubMed
40929214