Large-anisotropy limit of Heisenberg antiferromagnet: Towards description of pre-relaxation phenomena
Lenart Zadnik (LPTMS)
Seminar taking place at Batiment Pascal with ZOOM streaming.
ZOOM Meeting ID: 959 1349 7684
The recent decade has witnessed several breakthroughs in the description of relaxation of local observables in quantum many-body systems prepared far from equilibrium. In contrast, the time evolution on intermediate time scales that precede relaxation towards the stationary state has remained much less explored. Strong coupling expansions offer a good starting point for investigation of such problems, since they provide a natural time scale, on which the pre-relaxation can occur. We will discuss the effective Hamiltonian that generates time evolution of states on intermediate time scales in the large-anisotropy limit of Heisenberg spin-1/2 chain. Such an effective Hamiltonian describes a simple Bethe-Ansatz-solvable model with local interactions. Starting from a microscopic picture of the dynamics, I will explain the ballistic-scale hydrodynamic theory describing the time evolution after a quench, in which two halves of the system, thermalised at different temperatures, are abruptly joined.