Quenching Dynamics of a quantum XY spin-1/2 chain in presence of a transverse field

Details Quenching Dynamics of a quantum XY spin-1/2 chain in presence of a transverse field Quenching Dynamics of a quantum XY spin-1/2 chain in presence of a transverse field

2007-08-02

arxiv.org/abs/0708.0278v2

Phys. Rev. B 76, 174303 (2007)

Physics

Condensed Matter

Statistical Mechanics

8 pages, 6 figures

Scientific paper

10.1103/PhysRevB.76.174303

We study the quantum dynamics of a one-dimensional spin-1/2 anisotropic XY model in a transverse field when the transverse field or the anisotropic interaction is quenched at a slow but uniform rate. The two quenching schemes are called transverse and anisotropic quenching respectively. Our emphasis in this paper is on the anisotropic quenching scheme and we compare the results with those of the other scheme. In the process of anisotropic quenching, the system crosses all the quantum critical lines of the phase diagram where the relaxation time diverges. The evolution is non-adiabatic in the time interval when the parameters are close to their critical values, and is adiabatic otherwise. The density of defects produced due to non-adiabatic transitions is calculated by mapping the many-particle system to an equivalent Landau-Zener problem and is generally found to vary as $1/\sqrt{\tau}$, where $\tau$ is the characteristic time scale of quenching, a scenario that supports the Kibble-Zurek mechanism. Interestingly, in the case of anisotropic quenching, there exists an additional non-adiabatic transition, in comparison to the transverse quenching case, with the corresponding probability peaking at an incommensurate value of the wave vector. In the special case in which the system passes through a multi-critical point, the defect density is found to vary as $1/\tau^{1/6}$. The von Neumann entropy of the final state is shown to maximize at a quenching rate around which the ordering of the final state changes from antiferromagnetic to ferromagnetic.

Affiliated with

Also associated with

No associations

Rating

Quenching Dynamics of a quantum XY spin-1/2 chain in presence of a transverse field does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Quenching Dynamics of a quantum XY spin-1/2 chain in presence of a transverse field, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Quenching Dynamics of a quantum XY spin-1/2 chain in presence of a transverse field will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-244544