Rounding of a first-order quantum phase transition to a strong-coupling critical point

Autor(es)

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

Afiliação do(s) autor(es)

^[1] Missouri Univ Sci & Technol, Dept Phys, Rolla, MO 65409 - USA

^[2] Univ Sao Paulo, Inst Fis Sao Carlos, BR-13560970 Sao Carlos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Physical Review B; v. 86, n. 21 DEC 10 2012.
• Citações Web of Science: 14

Resumo

We investigate the effects of quenched disorder on first-order quantum phase transitions on the example of the N-color quantum Ashkin-Teller model. By means of a strong-disorder renormalization group, we demonstrate that quenched disorder rounds the first-order quantum phase transition to a continuous one for both weak and strong coupling between the colors. In the strong-coupling case, we find a distinct type of infinite-randomness critical point characterized by additional internal degrees of freedom. We investigate its critical properties in detail and find stronger thermodynamic singularities than in the random transverse field Ising chain. We also discuss the implications for higher spatial dimensions as well as unusual aspects of our renormalization-group scheme. DOI: 10.1103/PhysRevB.86.214204 (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