Quantum phase transitions in Bose-Fermi systems

TL;DR

This paper investigates how a single fermion affects quantum phase transitions in Bose-Fermi systems, revealing significant shifts in transition points and providing experimental evidence in odd-even nuclei.

Contribution

It introduces a combined classical and quantum analysis of Bose-Fermi systems, highlighting the fermion's impact on phase transition characteristics and critical parameters.

Findings

Fermion presence shifts the critical point of phase transition.

Strong influence of the fermion on the transition's nature.

Experimental evidence supports the theoretical predictions.

Abstract

Quantum phase transitions in a system of N bosons with angular momentum L=0,2 (s,d) and a single fermion with angular momentum j are investigated both classically and quantum mechanically. It is shown that the presence of the odd fermion strongly influences the location and nature of the phase transition, especially the critical value of the control parameter at which the phase transition occurs. Experimental evidence for the U(5)-SU(3) (spherical to axially-deformed) transition in odd-even nuclei is presented.