Scalar susceptibility of a diluted classical XY model

Abstract

We analyze the amplitude fluctuations in a diluted 3D classical XY model near the magnetic phase transition, motivated by the unusual localization properties of the amplitude (Higgs) mode recently found at the disordered superfluid-Mott glass quantum phase transition. We calculate the amplitude correlation function and the corresponding scalar susceptibility by means of Monte Carlo simulations. In contrast to the quantum case, in which the scalar susceptibility was found to violate naive scaling, we find that the scalar susceptibility of the classical system fulfills naive scaling (employing the clean critical exponents, as expected from the Harris criterion) as the temperature is varied across the phase transition for several dilutions. We discuss possible reasons for this discrepancy as well as the generality of our findings.

8 pages, 8 figures embedded, final version as published

References in corpus (5)

• Amplitude / Higgs Modes in Condensed Matter Physics
• The critical exponents of the superfluid transition in He4
• Quantum critical behavior of the superfluid-Mott glass transition
• Inhomogeneous mean-field approach to collective excitations in disordered interacting bosons
• Localization of the Higgs mode at the superfluid-Mott glass transition

Cited by in corpus (1)

• Critical Behavior and Collective Modes at the Superfluid Transition in Amorphous Systems