Ultrastrong Coupling Effects in Spin-Photon Interactions with Hole Spins

Quantum computing with semiconductor quantum dots offers a scalable platform compatible with industrial fabrication. Among the available qubit realisations, hole spins confined in double quantum dots stand out due to their strong intrinsic spin–orbit interaction and long coherence times. Recent expe...

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Detalhes bibliográficos
Autor: Satsangi, Shreya
Formato: tesis de maestría
Estado:Versión enviada para evaluación y publicación
Fecha de publicación:2025
País:España
Recursos:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:dnet:digitalcsic_::c4c6ced65d5d85679ff422321281f3ba
Acesso em linha:http://hdl.handle.net/10261/428480
Access Level:acceso abierto
Palavra-chave:quantum computing
double quantum dots
hole spins
spin–photon coupling
ultrastrong regime
spin–orbit interaction
computación cuántica
puntos cuánticos dobles
espines de huecos
acoplamiento espín–fotón
régimen ultrastrong
interacción espín–órbita
Descrição
Resumo:Quantum computing with semiconductor quantum dots offers a scalable platform compatible with industrial fabrication. Among the available qubit realisations, hole spins confined in double quantum dots stand out due to their strong intrinsic spin–orbit interaction and long coherence times. Recent experiments have demonstrated strong spin–photon coupling to microwave resonators, reaching interaction strengths that border the ultrastrong coupling regime. In this work, we theoretically analyse a hybrid system consisting of a hole spin in a double quantum dot coupled to a single-mode photonic cavity. Starting from a full four-level spin Hamiltonian, we identify and quantify the effective interaction terms between spin and photon degrees of freedom. Particular attention is paid to the emergence of spin–flip tunnelling contributions and counter-rotating terms that arise beyond the rotating-wave approximation. By parametrising the spin and charge photon coupling strengths, we study how counter-rotating terms introduce corrections to the physics of the hybrid system. We have also solved the ground state of the hybrid system. Our results provide analytical insight into additional coupling terms relevant in the ultrastrong regime, offering guidance for interpreting current experiments and designing future hybrid hole spin–photon architectures.