Adiabatic quantum dynamics of a transverse Ising chain with three spin interaction and ANNNI chain

Uma Divakaran

Indian Institute of Technology Kanpur, Department of Physics, Kanpur, India

We present 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 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 J3 = 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 present a study of 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.

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