Rounding by disorder of first-order quantum phase transitions: emergence of quantum critical points.
We give a heuristic argument for disorder rounding of a first-order quantum phase transition into a continuous phase transition. From both weak and strong disorder analysis of the N-color quantum Ashkin-Teller model in one spatial dimension, we find that, for N > or =3, the first-order transition is rounded to a continuous transition and the physical picture is the same as the random transverse field Ising model for a limited parameter regime. The results are strikingly different from the corresponding classical problem in two dimensions where the fate of the renormalization group flows is a fixed point corresponding to N-decoupled pure Ising models.
Goswami
Pallab
P
Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095-1547, USA.
Schwab
David
D
Chakravarty
Sudip
S