Rounding by Disorder of First-Order Quantum Phase Transitions: Emergence of Quantum Critical Points
Pallab Goswami, David Schwab, Sudip Chakravarty
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.
arXiv:0708.2917•Physical Review Letters•Jan 8, 2008•31 citations