Tuning the Two-step Melting of Magnetic Order in Dipolar Kagome Ice by Quantum Fluctuations

Complex magnetic orders in frustrated magnets may exhibit rich melting processes when the magnet is heated toward the paramagnetic phase. In this talk, we show that one may tune such melting processes by quantum fluctuations. We consider a kagome lattice dipolar Ising model subject to transverse field and focus on the thermal transitions out of its magnetic ground state, which features a root 3 by root 3 magnetic unit cell. Our quantum Monte Carlo (QMC) simulation suggests that, at weak transverse field, the root 3 by root 3 order melts by way of an intermediate, magnetically charge ordered phase where the lattice translation symmetry is restored whilst the time reversal symmetry remains broken[1]. By contrast, at moderate transverse field, QMC simulation suggests the root 3 by root 3 order melts through a floating Kosterlitz-Thouless (KT) phase. The two distinct melting processes are likely separated by a multicritical point identified in Ref.[2].


References:

1. Gia-Wei Chern, Paula Mellado, and O. Tchernyshyov, Phys. Rev. Lett. 106, 207202 (2011).
2. Kedar Damle, Phys. Rev. Lett. 115, 127204 (2015).