Inhomogeneous matrix product ansatz and exact solutions for strongly boundary driven spin chains
Lenart Zadnik (University of Ljubljana)
I will present a novel inhomogeneous Lax structure and demonstrate the exact solvability of a dissipatively boundary driven XYZ spin-1/2 chain in the limit of strong dissipation. I will describe the explicit inhomogeneous matrix product ansatz for the nonequilibrium steady state of the problem. The constituent matrices of this ansatz satisfy a simple set of linear recurrence relations. Although they can be embedded into an infinite-dimensional auxiliary space, they cannot be simultaneously put into a tridiagonal form, not even in the case of axially symmetric (XXZ) bulk interactions and general nonlongitudinal boundary dissipation. The results are expected to have further fundamental applications for the construction of nonlocal integrals of motion for the open XYZ model with arbitrary boundary fields.