Quantum phase transitions of the diluted O(3) rotor model

Abstract

We study the phase diagram and the quantum phase transitions of a site-diluted two-dimensional O(3) quantum rotor model by means of large-scale Monte-Carlo simulations. This system has two quantum phase transitions, a generic one for small dilutions, and a percolation transition across the lattice percolation threshold. We determine the critical behavior for both transitions and for the multicritical point that separates them. In contrast to the exotic scaling scenarios found in other random quantum systems, all these transitions are characterized by finite-disorder fixed points with power-law scaling. We relate our findings to a recent classification of phase transitions with quenched disorder according to the rare region dimensionality, and we discuss experiments in disordered quantum magnets.

11 pages, 14 eps figures, final version as published

References in corpus (5)

• Rare region effects at classical, quantum, and non-equilibrium phase transitions
• Quantum Griffiths effects in itinerant Heisenberg magnets
• Percolation quantum phase transitions in diluted magnets
• Quantum-criticality and percolation in dimer-diluted 2D antiferromagnets
• Ordering near the percolation threshold in models of 2D interacting bosons with quenched dilution

Cited by in corpus (14)

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• Phase boundary near a magnetic percolation transition
• Monte Carlo simulations of the disordered three-color quantum Ashkin-Teller chain
• Magnetic properties of diluted hexaferrites
• Percolation transition in quantum Ising and rotor models with sub-Ohmic dissipation
• Amplitude mode at the superfluid-insulator transition on a random lattice
• Computing quantum phase transitions
• Critical Behavior and Collective Modes at the Superfluid Transition in Amorphous Systems
• Quantum transitions from superfluid to insulating phases in disordered Bose systems
• Quantum critical behavior of diluted quasi-one-dimensional Ising chains
• On the Conditions for a Quantum Violent Relaxation