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The effect of the three-spin interaction and the next nearest neighbor interaction on the quenching dynamics of a transverse Ising model
, A. Dutta
Published in IOP PUBLISHING LTD
2007
Volume: 2007
   
Issue: 11
Abstract
We study the zero-temperature quenching dynamics of various extensions of the transverse Ising model (TIM) for 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 τ. 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 τ-1/2. In the first model considered here, the transverse Ising Hamiltonian includes an additional ferromagnetic three-spin interaction term of strength J3. For J3<0.5, the kink density is found to increase monotonically with J3 whereas it decreases with J3 for J3>0.5. The point with J 3 = 0.5 and the transverse field h = -0.5 is multicritical, where the density shows a slower decay given by τ-1/6. We also study the effect of ferromagnetic or antiferromagnetic next nearest neighbor (NNN) interactions on the dynamics of the 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 modify the dynamical behavior; for example an antiferromagnetic NNN interaction results in a larger number of kinks in the final state in comparison to the case when the NNN interaction is ferromagnetic. © IOP Publishing Ltd.
About the journal
JournalJournal of Statistical Mechanics: Theory and Experiment
PublisherIOP PUBLISHING LTD
ISSN17425468
Open AccessNo