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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Percolation transition in quantum Ising and rotor models with sub-Ohmic dissipation

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Al-Ali, Manal [1] ; Hoyos, Jose A. [2] ; Vojta, Thomas [1]
Total Authors: 3
[1] Missouri Univ Sci & Technol, Dept Phys, Rolla, MO 65409 - USA
[2] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Paulo - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Physical Review B; v. 86, n. 7 AUG 13 2012.
Web of Science Citations: 2

We investigate the influence of sub-Ohmic dissipation on randomly diluted quantum Ising and rotor models. The dissipation causes the quantum dynamics of sufficiently large percolation clusters to freeze completely. As a result, the zero-temperature quantum phase transition across the lattice percolation threshold separates an unusual super-paramagnetic cluster phase from an inhomogeneous ferromagnetic phase. We determine the low-temperature thermodynamic behavior in both phases, which is dominated by large frozen and slowly fluctuating percolation clusters. We relate our results to the smeared transition scenario for disordered quantum phase transitions, and we compare the cases of sub-Ohmic, Ohmic, and super-Ohmic dissipation. (AU)

FAPESP's process: 10/03749-4 - Quantum phase transitions: effects of disorder and dissipation
Grantee:José Abel Hoyos Neto
Support type: Regular Research Grants