Phys.org  February 13, 2024 To investigate light-matter hybrid excitations in a quantum dot (QD) THz resonator coupled system researchers in Japan fabricated a gate-defined QD near a THz split-ring resonator (SRR) by using a AlGaAs/GaAs two-dimensional electron system. By illuminating the system with THz radiation, the QD showed a current change whose spectrum exhibited coherent coupling between the electrons in the QD and the SRR as well as coupling between the two-dimensional electron system and the SRR. The latter coupling entered the ultrastrong coupling regime and the electron excitation in the QD also exhibited coherent coupling with the SRR with […]