Laboratoire Matière et Systèmes Complexes

Long-range phase order in two-dimensions under shear

Shin-Ichi Sasa

Abstract:

According to the Mermin-Wagner theorem, O(2) symmetric models do not exhibit l ong-range phase order in two dimensions at equilibrium. Here, when the order parameter is convected by shear flow, the system becomes anisotropic, out of equilibrium, but still keeps the O(2) symmetry. We then show that the long-range phase order emerges even for small shear rate by analyzing non-equilibrium phase dynamics. Furthermore, by numerical simulations of the Ginzburg-Landau model with shear, we present evidence for this theoretical analysis and study the nature of the phase transition to the ordered phase from the disordered phase. This work was done in collaboration with H. Nakano and Y. Minami. See also the reference [H. Nakano, Y. Minami, S.-i. Sasa, Phys. Rev. Lett. 126, 160604 (2021).]According to the Mermin-Wagner theorem, O(2) symmetric models do not exhibit l ong-range phase order in two dimensions at equilibrium. Here, when the order parameter is convected by shear flow, the system becomes anisotropic, out of equilibrium, but still keeps the O(2) symmetry. We then show that the long-range phase order emerges even for small shear rate by analyzing non-equilibrium phase dynamics. Furthermore, by numerical simulations of the Ginzburg-Landau model with shear, we present evidence for this theoretical analysis and study the nature of the phase transition to the ordered phase from the disordered phase. This work was done in collaboration with H. Nakano and Y. Minami. See also the reference [H. Nakano, Y. Minami, S.-i. Sasa, Phys. Rev. Lett. 126, 160604 (2021).]