304th RQC Seminar

• 講演者

  Prof. Adam Miranowicz
  ( Adam Mickiewicz University, Poland )

• 日程

  2026年9月28日(月), 16:00 - 17:00(4:00 p.m.-5:00 p.m.)

• 開催場所

  ハイブリッド（Zoom,
  345-347 Seminar Room, 3F, Main Research Building, Wako Campus / 和光地区 研究本館3階 セミナー室 (345-347) (C01)）

• 講演タイトル

  Quantum Liouvillian Singularities: Recent Theory and Experimental Advances

• お問合せ

  norilab_rqc_assist[at]ml.riken.jp

講演概要
Exceptional points (EPs) of non-Hermitian Hamiltonians have attracted considerable attention since the 1960s. However, Hamiltonian EPs do not provide a complete description of quantum dynamics because they neglect the effect of quantum jumps. To overcome this limitation, the concept has been generalized to Liouvillian exceptional points (LEPs), where singularities are studied for the Liouvillian superoperator represented as a matrix in Liouville (dual) space. Unlike Hamiltonian EPs, LEPs naturally incorporate the effects of quantum jumps.

In this talk, I will discuss various types of Liouvillian singularities, extending beyond exceptional points to include diabolical points, hybrid degeneracies combining exceptional and diabolical features, and singularities of $q$-deformed Liouvillians, where the deformation parameter $q$ is associated with the statistics of post-selected quantum trajectories containing a prescribed number of quantum jumps.

I will first introduce the general concepts underlying these singularities and then present a number of recent experiments that confirm our theoretical predictions. The discussion will not be limited to Liouvillians generated by Lindblad master equations but will also include non-Markovian quantum master equations.

Applications of Hamiltonian exceptional points range from sensing to detecting quantum phase transitions. The range of applications of Liouvillian exceptional points is also expanding rapidly, including emerging applications in quantum thermodynamics. For example, LEPs have recently been shown experimentally to enhance the performance of quantum heat engines.

We believe that research on Liouvillian singularities is still in its early stages and that many new physical phenomena and practical applications will emerge in the coming years.