Quantum Rabi system in the ultrastrong coupling regime as a photon converter

• Grant number: 23/09171-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2023
• End date: September 30, 2024
• Field of knowledge: Physical Sciences and Mathematics - Physics - General Physics
• Principal Investigator: Daniel Zini Rossatto
• Grantee: Enzzo Perez
• Host Institution: Instituto de Ciência e Engenharia. Universidade Estadual Paulista (UNESP). Campus Experimental de Itapeva. Itapeva , SP, Brazil

Abstract

In recent years, the ultrastrong and deep-strong coupling regimes between radiation and matter have evolved from theoretical proposals to experimental reality, being achieved in different quantum platforms. These regimes have exhibited novel and surprising physical phenomena, some of which show significant potential for applications in quantum information science. Particularly, when a system enters the ultrastrong coupling regime, a drastic change occurs in its emission spectrum. The present research project aims to theoretically investigate the emission spectrum of the quantum Rabi model in the ultrastrong (and deep-strong) coupling regime, exploring the potential of utilizing this system as a photon converter. In this regime, a crossing between two excited level eigenstates of the system enables the absorption of a single photon, which can then be converted into three photons, typically with distinct frequencies, emitted in a cascade-like manner. To analyze the system, we will employ the microscopic formalism of the master equation and utilize Python programming for the simulation of open quantum system dynamics.