Spinon confinement in a quasi-one-dimensional anisotropic Heisenberg magnet
PHYSICAL REVIEW B 96:5 (2017) ARTN 054423
Spinon decay in the spin-1/2 Heisenberg chain with weak next nearest neighbour exchange
Journal of Physics A: Mathematical and Theoretical IOP Publishing 50:33 (2017) 334002
Abstract:
Integrable models support elementary excitations with infinite lifetimes. In the spin-1/2 Heisenberg chain these are known as spinons. We consider the stability of spinons when a weak integrability breaking perturbation is added to the Heisenberg chain in a magnetic field. We focus on the case where the perturbation is a next nearest neighbour exchange interaction. We calculate the spinon decay rate in leading order in perturbation theory using methods of integrability and identify the dominant decay channels. The decay rate is found to be small, which indicates that spinons remain well-defined excitations even though integrability is broken.On truncated generalized Gibbs ensembles in the Ising field theory
Journal of Statistical Mechanics: Theory and Experiment IOP Publishing 2017:1 (2017) 013103
Abstract:
We discuss the implementation of two dierent truncated Generalized Gibbs Ensembles (GGE) describing the stationary state after a mass quench process in the Ising Field Theory. One truncated GGE is based on the semi-local charges of the model, the other on regularized versions of its ultra-local charges. We test the efficiency of the two different ensembles by comparing their predictions for the stationary state values of the single-particle Green's function G(x) = ⟨Ψ†(x)Ψ(0)⟩ of the complex fermion field Ψ(x). We find that both truncated GGEs are able to recover G(x), but for a given number of charges the semi-local version performs better.
Exact Bethe ansatz spectrum of a tight-binding chain with dephasing noise
Physical Review Letters American Physical Society 117:13 (2016) 137202
Abstract:
We construct an exact map between a tight-binding model on any bipartite lattice in the presence of dephasing noise and a Hubbard model with imaginary interaction strength. In one dimension, the exact many-body Liouvillian spectrum can be obtained by application of the Bethe ansatz method. We find that both the nonequilibrium steady state and the leading decay modes describing the relaxation at late times are related to the η-pairing symmetry of the Hubbard model. We show that there is a remarkable relation between the time evolution of an arbitrary k-point correlation function in the dissipative system and k-particle states of the corresponding Hubbard model.Quantum quenches to the attractive one-dimensional Bose gas: exact results
SciPost Physics SciPost (2016)