Rounding by disorder of first-order quantum phase transitions: emergence of quantum critical points

Abstract

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 the N-color quantum Ashkin-Teller model in one spatial dimension, we find that for $N\ge 3$, 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.

Title is modified as requested by the PRL editor, minor stylistic changes, typos corrected, and a few new references added. It is published in PRL

Cited by in corpus (8)

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• Rounding of a first-order quantum phase transition to a strong-coupling critical point
• Bond disorder induced criticality of the three-color Ashkin-Teller model
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• Monte Carlo simulations of the disordered three-color quantum Ashkin-Teller chain
• Emergent universal critical behavior of the 2D $N$-color Ashkin-Teller model in the presence of correlated disorder
• Smeared phase transition in the dissipative random quantum Ashkin-Teller model
• Interplay of Quantum and Thermal Fluctuations in Two-Dimensional Randomly Pinned Charge Density Waves