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Q: Fachverband Quantenoptik und Photonik
Q 25: Quantum Effects: Cavity QED II
Q 25.4: Talk
Tuesday, March 7, 2017, 15:15–15:30, P 4
Microcanonical description of an extended Dicke model — •Miguel A. Bastarrachea-Magnani1, Sergio Lerma-Hernández2, and Jorge G. Hirsch3 — 1Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, Germany. — 2Facultad de Física, Universidad Veracruzana, México. — 3Instituto de Ciencias Nucleares, México.
A paradigmatic model in quantum optics, the Dicke Hamiltonian, describes a system of N two-level atoms interacting with a single monochromatic electromagnetic radiation mode within a cavity. Its algebraic simplicity makes it suitable to describe qubit systems interacting with a bosonic field within the quantum information framework. The model is known because it exhibits a quantum phase transition, both in the ground state and in the excitation spectrum, which can be related to the underlying, classically chaotic spin dynamics, and implies certain entanglement properties. A general question is how the spectral properties of a quantum system are reflected in its thermodynamical phase diagram. In this work it is employed a semi-classical approximation to calculate the thermodynamics of an extended Dicke model in the microcanonical ensemble. The results are compared to calculations for the canonical ensemble. A straightforward thermodynamical manifestation of the critical phenomena on the spectral level is derived.