RQC Seminar

220th RQC Seminar

• Speaker

  Mr. Gong RuiYang
  ( Sun Yat-Sen University )

• Date

  16:00-17:00 (4:00 p.m. - 5:00 p.m.), August 21, 2025 Thursday)

• Venue

  Onsite( Wako Main Research Bldg. 5F 535-537 Meeting Room / 研究本館5階 会議室 (535-537) (C01))

• Title

  Constructing Quantum Networks in Waveguide QED Systems via Propagating Photon States

• Inquiries

  norilab_rqc_assist[at]ml.riken.jp

Abstract
Quantum networks are considered the most promising framework for scalable quantum information processing and communication, where quantum state transfer as a key ingredient has attracted increasing attention in recent years. This talk first introduces a tunable quantum router embedded in a dual-rail waveguide, which implements quantum gates, teleportation, non-reciprocity, and circulators. Then, the experimental result of inter-chip quantum connectivity over meter-scale distances through a superconducting-qubit platform will be presented. We designed and fabricated a state-transfer protocol utilizing Gmon as tunable couplers. By varying the coupling strength, we observed the conversion between the stationary and flying photon regions and achieved distributed quantum interconnection at temperatures of both 10 mK and above 1 K.
Moreover, we explored light-atom interaction effects through the analysis of propagating photon characteristics in waveguides. In multi-artificial-qubit systems, phenomena arising from light-atom interactions, specifically electromagnetically induced transparency (EIT) and Autler-Townes splitting (ATS), were observed. Furthermore, we analyzed resonant fluorescence and second-order correlation effects of scattered photons within giant atom systems. Finally, within the context of correlated emission laser (CEL), we realized laser gain and generated squeezed states with squeezing levels exceeding 3 dB.