Influence of super-ohmic dissipation on a disordered quantum critical point

We investigate the combined influence of quenched randomness and dissipation on a quantum critical point with O(N) order-parameter symmetry. Utilizing a strong-disorder renormalization group, we determine the critical behavior in one space dimension exactly. For super-ohmic dissipation, we find a Kosterlitz-Thouless type transition with conventional (power-law) dynamical scaling. The dynamical critical exponent depends on the spectral density of the dissipative baths. We also discuss the Griffiths singularities, and we determine observables.

NSF[DMR-0339147]

U.S. National Science Foundation (NSF)

U.S. National Science Foundation (NSF)

NSF[PHY-0551164]

U.S. National Science Foundation (NSF)

NSF[DMR-0906566]

Research Corporation

Research Corporation

FAPESP[2010/03749-4]

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

CNPq[302301/2009-7]

DST[PHY/10-11/232/DSTX/ALAK]

DST