Physics ColloquiumSpeaker: Alexey Galda Location: LD 010
Parity-time symmetry and exceptional points in open magnetic systems
Abstract: The understanding of out-of-equilibrium physics, especially dynamic instabilities and phase transitions, is one of the major challenges of contemporary science. Focusing on non-equilibrium dynamics of open dissipative spin systems, I will introduce a non-Hermitian Hamiltonian formalism, in which non-Hermiticity reflects dissipation and presence of non-conservative forces. I will show how non-Hermitian Hamiltonians admit branch point singularities that appear as chiral exceptional points, where both eigenvalues and eigenstates coalesce. I will discuss the appearance of these exceptional spectral points in relation to parity-time symmetry, and how it provides access to a wealth of topological effects unique to non-Hermitian systems, e.g. asymmetric spin transport and non-reciprocal time evolution.
Refreshments will be served in LD 154B from 3:00-3:30pm.