Current-driven defect-unbinding transition in anXYferromagnet

Abstract

A Keldysh-contour effective field theory is derived for magnetic vortices in the presence of current flow. The effect of adiabatic and non-adiabatic spin transfer torques on vortex motion is highlighted. Similarities to and differences from the superconducting case are presented and explained. Current flow across a magnetically ordered state is shown to lead to a defect-unbinding phase transition which is intrinsically nonequilibrium in the sense of not being driven by a variation in effective temperature. The dependence of the density of vortices on the current density is determined.

Understanding Quantum Confinement of Charge Carriers in Layered 2D Hybrid Perovskites

“…For a complex stack, a manybody treatment is beyond reach, but the DFT potential drop at the interface can be efficiently corrected by the self-energy (GW approximation, where G is the single particule Green's function and W the screened Coulomb interaction) eigenvalues obtained for the bulk VB states. [43][44][45] However in a number of situations, the EFA fails to reproduce the experimental results even for coherent interfaces. This might happen when local symmetry breaking occurs at the interface or an interface-related mixing between bulk eigenstates located at different points of the Brillouin zone drives the heterostructure electronic states.…”

Nonequilibrium phase transition in a driven-dissipative quantum antiferromagnet

“…Quenches, i.e., abrupt changes in Hamiltonian parameters, can lead to dynamical phase transitions [7,8] characterized by qualitative modifications of the dynamical response as the quench magnitude is varied. However, phase transitions occurring as the drive amplitude is varied in a nonequilibrium steady state are less explored [9][10][11][12][13][14]. Driven-dissipative phase transitions and Bose-Einstein condensation (BEC) in polaritonic systems have been theoretically analyzed [2,15] and experimentally demonstrated [5,6,[16][17][18].…”