Strong randomness criticality in the scratched XY model

Pfeffer, Tobias; Yao, Zhiyuan und Pollet, Lode (2019): Strong randomness criticality in the scratched XY model. In: Physical Review B, Vol. 99, No. 10, 104514

Abstract

We study the finite-temperature superfluid transition in a modified two-dimensional (2D) XY model with power-law-distributed "scratch"-like bond disorder. As its exponent decreases, the disorder grows stronger and the mechanism driving the superfluid transition changes from conventional vortex-pair unbinding to a strong randomness criticality (termed scratched XY criticality) characterized by a nonuniversal jump of the superfluid stiffness. The existence of the scratched XY criticality at finite temperature and its description by an asymptotically exact semi-renormalization group theory, previously developed for the superfluid-insulator transition in one-dimensional disordered quantum systems, is numerically proven by designing a model with minimal finite-size effects. Possible experimental implementations are discussed.

• Item Type: Journal article
• Faculties: Physics
• Subjects: 500 Science > 530 Physics
• ISSN: 2469-9950
• Language: English