000151385 001__ 151385
000151385 005__ 20250319143308.0
000151385 0247_ $$2doi$$a10.1103/PhysRevB.111.035156
000151385 0248_ $$2sideral$$a143087
000151385 037__ $$aART-2025-143087
000151385 041__ $$aeng
000151385 100__ $$0(orcid)0000-0003-2995-6615$$aRomán-Roche, Juan
000151385 245__ $$aLinear response theory for cavity QED materials at arbitrary light-matter coupling strengths
000151385 260__ $$c2025
000151385 5060_ $$aAccess copy available to the general public$$fUnrestricted
000151385 5203_ $$aWe develop a linear response theory for materials collectively coupled to a cavity that is valid in all regimes of light-matter coupling, including symmetry-broken phases. We present and compare two different approaches. First, we use a coherent path-integral formulation for the partition function to obtain thermal Green's functions. This approach relies on a saddle-point expansion for the action that can be truncated in the thermodynamic limit. Second, we formulate the equations of motion for the retarded Green's functions and solve them. We use a mean-field decoupling of high-order Green's functions to obtain a closed, solvable system of equations. Both approaches yield identical results in the calculation of response functions for the cavity and material. These are obtained in terms of the bare cavity and material responses. In combination, the two techniques clarify the validity of a mean-field decoupling in correlated light-matter systems and provide complementary means to compute finite-size corrections to the thermodynamic limit. The theory is formulated for a general model that encompasses most of the systems typically considered in the field of cavity QED materials. Finally, we provide a detailed application of the theory to the quantum Hall effect and to a collection of spin models.
000151385 536__ $$9info:eu-repo/grantAgreement/ES/AEI/CEX2023-001286-S$$9info:eu-repo/grantAgreement/ES/DGA/E09-17R-Q-MAD$$9info:eu-repo/grantAgreement/EUR/MICINN/TED2021-131447B-C21
000151385 540__ $$9info:eu-repo/semantics/openAccess$$aby-nc-nd$$uhttp://creativecommons.org/licenses/by-nc-nd/3.0/es/
000151385 655_4 $$ainfo:eu-repo/semantics/article$$vinfo:eu-repo/semantics/acceptedVersion
000151385 700__ $$aGómez-León, Álvaro
000151385 700__ $$0(orcid)0000-0001-6284-0521$$aLuis Vitalla, Fernando
000151385 700__ $$0(orcid)0000-0003-4478-1948$$aZueco, David
000151385 773__ $$g111, 3 (2025), 035156 [21 pp.]$$pPhys. Rev. B$$tPhysical Review B$$x2469-9950
000151385 8564_ $$s2011399$$uhttps://zaguan.unizar.es/record/151385/files/texto_completo.pdf$$yPostprint
000151385 8564_ $$s3181230$$uhttps://zaguan.unizar.es/record/151385/files/texto_completo.jpg?subformat=icon$$xicon$$yPostprint
000151385 909CO $$ooai:zaguan.unizar.es:151385$$particulos$$pdriver
000151385 951__ $$a2025-03-19-14:32:17
000151385 980__ $$aARTICLE