Quantum Phase Transitions on Percolating Lattices
When a quantum many-particle system exists on a randomly diluted lattice, its intrinsic thermal and quantum fluctuations coexist with geometric fluctuations due to percolation. In this paper, we explore how the interplay of these fluctuations influences the phase transition at the percolation threshold. While it is well known that thermal fluctuations generically destroy long-range order on the critical percolation cluster, the effects of quantum fluctuations are more subtle. In diluted quantum magnets with and without dissipation, this leads to novel universality classes for the zero-temperature percolation quantum phase transition. Observables involving dynamical correlations display nonclassical scaling behavior that can nonetheless be determined exactly in two dimensions.
T. Vojta and J. A. Hoyos, "Quantum Phase Transitions on Percolating Lattices," American Physical Society Meeting 2007, American Physical Society (APS), Jan 2007.
National Science Foundation (U.S.)
University of Missouri Research Board
Keywords and Phrases
Percolation; Quantum Magnet; Quantum Phase Transition; Strongly Correlated Electrons
Article - Conference proceedings
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