Single-photon frequency comb generation in a giant-atom cavity coupled to a one-dimensional waveguide
Phys. Rev. A 113, 013706 – Published 2 January, 2026
DOI: https://doi.org/10.1103/wl2k-ks4b
Abstract
Giant atoms enable precise control over single-photon dynamics in waveguide-based quantum circuits through spatially distributed interactions with the guided electromagnetic modes. Recent advancements in the realm of superconducting circuits allow for experimental implementation of giant atoms. In this work, we describe a microscopic model of a transmon qubit coupled to a transmission line and show that its Hamiltonian maps onto a generalized form for giant-atom-waveguide interactions. We demonstrate the generation of a frequency comb from a system comprising a single-photon Gaussian pulse incident on a cavity with giant-atom mirrors coupled to a one-dimensional waveguide. The finesse of this single-photon frequency comb can be significantly improved by using giant atoms instead of point atoms. Furthermore, this high-finesse cavity enables a substantial enhancement of the peaks in the comb spectra when the photon pulse is initially inside the giant-atom cavity. Our work provides a platform for the design of advanced quantum devices for high-resolution spectroscopy and quantum computation.
