RQC Seminar

196th RQC Seminar

• Speaker

  Mr. Daniele Lamberto
  ( University of Messina, Italy )

• Date

  16:00-17:00 (4:00 p.m. - 5:00 p.m.), May 16, 2025 (Friday)

• Venue

  Hybrid(ZOOM・ Wako Main Research 3F 345-347 Seminar Room / 研究本館3階 セミナー室 (345-347) (C01))

• Title

  Perfect Absorption in Hyperfine Levels of Molecular Spins with Hermitian Subspaces

• Inquiries

  norilab_rqc_assist[at]ml.riken.jp

Abstract
Ideal effective parity-time (PT)-symmetry can be achieved in a passive open system by accurately balancing feeding and absorption processes. Such PT-symmetric systems exhibit perfect absorption (PA) of radiation, i.e. all incoming energy is absorbed by the system. In this work, we consider a passive open quantum system obtained by coupling molecular spin centers to a planar microwave resonator. We experimentally demonstrate that PA can be obtained even in the absence of PT-symmetry, by exploiting the spin detuning to control the photon and spin content of a polariton mode. In such a way, effective Hermitian subspaces can be generated, and the required balance between the feeding and the loss rates is recovered. Hermitian subspaces influence the overall aspect of coherent spectra of cavity QED systems and significantly enlarge the possibility to explore non-Hermitian effects in open quantum systems. We finally discuss how Hermitian subspaces can be potentially exploited for the development of efficient switches and modulators with high modulation depths over a broad spectral range.