Thermodynamic Analogy for Structural Phase Transitions

Abstract

We investigate the relationship between ground-state (zero-temperature) quantum phase transitions in systems with variable Hamiltonian parameters and classical (temperature-driven) phase transitions in standard thermodynamics. An analogy is found between (i) phase-transitional distributions of the ground-state related branch points of quantum Hamiltonians in the complex parameter plane and (ii) distributions of zeros of classical partition functions in complex temperatures. Our approach properly describes the first- and second-order quantum phase transitions in the interacting boson model and can be generalized to finite temperatures.

Comments: to be published by AIP in Proc. of the Workshop "Nuclei and Mesoscopic Physics" (Michigan State Univ., Oct 2004); 10 pages, 3 figures