paper

The effect of the three-spin interaction and the next-nearest neighbor interaction on the quenching dynamics of a transverse Ising model

arXiv:0801.2621

Abstract

We study the zero temperature quenching dynamics of various extensions of the transverse Ising model (TIM) when the transverse field is linearly quenched from to (or zero) at a finite and uniform rate. The rate of quenching is dictated by a characteristic scale given by . The density of kinks produced in these extended models while crossing the quantum critical points during the quenching process is calculated using a many body generalization of the Landau-Zener transition theory. The density of kinks in the final state is found to decay as . In the first model considered here, the transverse Ising Hamiltonian includes an additional ferromagnetic three spin interaction term of strength . For , the kink density is found to increase monotonically with whereas it decreases with for . The point and the transverse field is multicritical where the density shows a slower decay given by . We also study the effect of ferromagnetic or antiferromagnetic next nearest neighbor (NNN) interactions on the dynamics of TIM under the same quenching scheme. In a mean field approximation, the transverse Ising Hamiltonians with NNN interactions are identical to the three spin Hamiltonian. The NNN interactions non-trivially modifies the dynamical behavior, for example an antiferromagnetic NNN interactions results to a larger number of kinks in the final state in comparison to the case when the NNN interaction is ferromagnetic.

7 pages, 4 figures