Date: Tue. October 13, 2026 (15:30H)
Event: DeustoCCM Seminar
General Colloquium / Research-Oriented
Title: Energy spectra for Light-Matter Interactions
Speaker: Prof. Masato Wakayama
Affiliation: NTT Institute for Fundamental Mathematics | ZEN University | Kyushu University
Visiting Scientist at DeustoCCM, Chair of Computational Mathematics. University of Deusto
Abstract. The quantum Rabi model (QRM) describes one of the most fundamental models used in quantum optics. Interaction models discussed in this talk are the asymmetric QRM (AQRM), the two-photon quantum Rabi model (2pQRM) and the non-commutative harmonic oscillator (NCHO), which is equivalent to the 2pQRM in terms of its eigenvalue problem. The AQRM is a theoretical model— predicting experimental measurements—that serves as a model for the fundamental elements of superconducting quantum computers. Furthermore, when their eigenvalue problems are formulated using Heun ODEs, NCHO/2pQRM can be regarded as a covering model of QRM from the perspective of the confluence of regular singularities. The talk discusses the derivation and geometric interpretation of an analytical formula for the heat kernel of the (A)QRM—utilizing the Trotter-Kato product formula, which is sometimes mathematically regarded as a Feynman path integral—as well as conjectures on energy degeneracy to hidden symmetries not apparent in the Hamiltonian of AQRM (and 2pAQRM) and a mysterious approximation to the spectral curves closely related to the degeneracy.
WHERE
Onsite / Online
Onsite: University of Deusto, DeustoTech.
Room: Logistar.
Unibertsitate Etorb., 24, 48007 Bilbao, Bizkaia
Online: (gMeet): http://meet.google.com/nez-yvqa-ovm