Dissipation effects in random transverse-field Ising chains

Autor(es)

Hoyos, Jose A. ^[1] ; Vojta, Thomas ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Paulo - Brazil

^[2] Missouri Univ Sci & Technol, Dept Phys, Rolla, MO 65409 - USA

• Tipo de documento: Artigo Científico
• Fonte: Physical Review B; v. 85, n. 17, p. 174403, 2012.
• Citações Web of Science: 9

Resumo

We study the effects of Ohmic, super-Ohmic, and sub-Ohmic dissipation on the zero-temperature quantum phase transition in the random transverse-field Ising chain by means of an (asymptotically exact) analytical strong-disorder renormalization-group approach. We find that Ohmic damping destabilizes the infinite-randomness critical point and the associated quantum Griffiths singularities of the dissipationless system. The quantum dynamics of large magnetic clusters freezes completely, which destroys the sharp phase transition by smearing. The effects of sub-Ohmic dissipation are similar and also lead to a smeared transition. In contrast, super-Ohmic damping is an irrelevant perturbation; the critical behavior is thus identical to that of the dissipationless system. We discuss the resulting phase diagrams, the behavior of various observables, and the implications to higher dimensions and experiments. (AU)

• Processo FAPESP: 10/03749-4 - Transições de fase quânticas: efeitos de desordem e dissipação
• Beneficiário: José Abel Hoyos Neto
• Modalidade de apoio: Auxílio à Pesquisa - Regular