Friday, August 3, 2012

1208.0471 (Fawaz Hrahsheh et al.)

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

Fawaz Hrahsheh, José A. Hoyos, Thomas Vojta
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 we discuss broader implications for the fate of first-order quantum phase transitions in disordered systems.
View original: http://arxiv.org/abs/1208.0471

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