95530 20220426091138.0 doi 10.1103/PhysRevA.102.023702 sideral 119903 ART-2020-119903 eng Román-Roche, J. Universidad de Zaragoza (orcid)0000-0003-2995-6615 Bound states in ultrastrong waveguide QED 2020 Access copy available to the general public Unrestricted We discuss the properties of bound states in finite-bandwidth waveguide QED beyond the rotating wave approximation or excitation-number-conserving light-matter coupling models. Therefore, we extend the standard calculations to a broader range of light-matter strengths, in particular, in the so-called ultrastrong coupling regime. We do this using the polaron technique. Our main results are as follows: We compute the spontaneous emission rate, which is renormalized as compared with the Fermi golden rule formula. We generalize the existence criteria for bound states, their properties, and their role in the qubit thermalization. We discuss effective spin-spin interactions through both vacuum fluctuations and bound states. Finally, we sketch a perfect state-transfer protocol among distant emitters mediated by bound states. info:eu-repo/grantAgreement/EC/H2020/742102/EU/Quantum Emitters in non-conventional baths/QUENOCOBA This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No H2020 742102-QUENOCOBA info:eu-repo/grantAgreement/ES/MCIU/MAT2017-88358-C3-1-R info:eu-repo/grantAgreement/EUR/MOLSPIN-COST/CA15128 info:eu-repo/semantics/openAccess by http://creativecommons.org/licenses/by/3.0/es/ 3.14 2020 PHYSICS, ATOMIC, MOLECULAR & CHEMICAL 10 / 37 = 0.27 2020 Q2 T1 OPTICS 31 / 99 = 0.313 2020 Q2 T1 1.391 2020 Atomic and Molecular Physics, and Optics 2020 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Sánchez-Burillo, E. (orcid)0000-0002-3230-5824 Zueco, D. Universidad de Zaragoza (orcid)0000-0003-4478-1948 2003 395 Universidad de Zaragoza Dpto. Física Materia Condensa. Área Física Materia Condensada 102, 2 (2020), 023702 [17 pp.] Phys. rev., A Physical Review A 2469-9926 1375666 http://zaguan.unizar.es/record/95530/files/texto_completo.pdf Versión publicada 655555 http://zaguan.unizar.es/record/95530/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:95530 articulos driver 2022-04-26-08:55:05 ARTICLE