Mucio A. CONTINENTINO (Centro Brasileiro de Pesquisas Físicas, Rio de Janeiro, Brazil)
24 juin @ 10:00
Dehybridization transition in multi-band systems: a renormalization group approach
Résumé :
In strongly correlated multi-band systems, such as transition metal intermetallics, heavy fermions, and Kondo insulators, electron-electron interactions lead to the damping of electronic quasiparticles at finite temperatures. This phenomenon results in an effective dehybridization between the electrons in the large conduction band and those in the narrow, correlated band. The dehybridization effect has been employed to explain the transport properties of intermetallics and the results of angle-resolved photoemission spectroscopy (ARPES) experiments on heavy fermions at sufficiently high temperatures (1). Recent insights from the theory of non-Hermitian systems provide a novel perspective on this problem. In this work, we adopt this viewpoint through a renormalization group (RG) approach. We derive RG equations for a one-dimensional two-band model to identify the exceptional points of this system and to characterize its topological properties in the presence of dissipation. Our findings reveal that for a non- trivial topological sp-chain, dehybridization can be interpreted as a topological phase transition, characterized by critical exponents that we calculate. By employing a parametrization of the self-energy in a strongly correlated system, computed numerically, we investigate the temperature dependence of the lifetime of heavy quasiparticles. From these results, a characteristic temperature related to dehybridization emerges. We discuss whether this temperature represents a new energy scale or if it is associated with the Kondo or coherence temperatures in the phase diagram of heavy fermions [2].
References
1. C. Adriano, F. Rodolakis, P. F. S. Rosa, F. Restrepo, M. A. Continentino, Z. Fisk, J. C. Campuzano, and P. G. Pagliuso, Unveiling the hybridization gap in Ce2RhIn8 heavy fermion compound, arXiv:1502.02544 [cond-mat.str-el], https://doi.org/10.48550/arXiv.1502.02544
2. Dehybridization transition in Kondo insulators and heavy fermions, arXiv:2505.04730. https://doi.org/10.48550/arXiv.2505.04730
1. C. Adriano, F. Rodolakis, P. F. S. Rosa, F. Restrepo, M. A. Continentino, Z. Fisk, J. C. Campuzano, and P. G. Pagliuso, Unveiling the hybridization gap in Ce2RhIn8 heavy fermion compound, arXiv:1502.02544 [cond-mat.str-el], https://doi.org/10.48550/arXiv.1502.02544
2. Dehybridization transition in Kondo insulators and heavy fermions, arXiv:2505.04730. https://doi.org/10.48550/arXiv.2505.04730
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Contact : claudine.lacroix@neel.cnrs.fr