Self-interacting Fermionic Models

A. S. Alexandrov

A model of hybridized bosons and fermions is studied beyond the mean field approximation. The divergent boson self-energy at zero temperature makes the Cooper pairing of fermions impossible. The frequency and momentum dependence of the self- energy and the condensation temperature $T_{c}$ of initially localized bosons are calculated analytically. The value of the boson condensation temperature $T_{c}$ is below $1K$ which rules out the boson-fermion model with the initially localized bosons as a phenomenological explanation of high-temperature superconductivity. The intra-cell density-density fermion-boson interaction dominates in the fermion self-energy. The model represents a normal metal with strongly damped bosonic excitations. The latter play the role of normal impurities.

Joel Feldman, J Magnen, Vincent Rivasseau +1 more

A. S. Alexandrov

A model of hybridized bosons and fermions is studied beyond the mean-field approximation. The divergent boson self-energy at zero temperature makes the Cooper pairing of fermions impossible. The frequency and momentum dependence of the self-energy and the condensation temperature of initially localized bosons are calculated analytically. The value of the boson condensation temperature is below 1 K and the long-wave spectrum is strongly damped which rules out the boson - fermion model with the initially localized bosons as a phenomenological explanation of high-temperature superconductivity. The intra-cell density - density fermion - boson interaction dominates in the fermion self-energy. The model represents a dirty normal metal, in which localized bosons play the role of impurities.

Andrey R. Kolovsky, Dima L. Shepelyansky

Abstract Depletion dynamics of an open system of weakly interacting fermions with two‐body random interactions is studied. In this model, fermions are escaping from the high‐energy one‐particle orbitals, that mimics the evaporation process used in laboratory experiments with neutral atoms to cool them to ultra‐low temperatures. It is shown that due to self‐thermalization the system instantaneously adjusts to the new temperature which decreases with the course of time.

Joachim Alexander Maruhn, P.‐G. Reinhard, E. Suraud