Research Paper: Study of Geometric Measure of Entanglement Produced by One-axis Counter Twisting Hamiltonian in Spin Systems

Document Type : Research Paper

Authors

1 Assistant Professor, Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran

2 M. Sc. in Physics, Department of Physics, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran.

Abstract

Generation of entanglement in separable two qubits states using the one-axis counter twisting Hamiltonian in the presence/absence of a magnetic field is studied by introducing the geometric measure of entanglement. The exact expression for the geometric measure is obtained without calculating the time evolution of the system state using the method of the expectation values of spin. The graphs of this measure as a function of time are plotted. The results show that in order to obtain the maximum entanglement under the influence of one-axis counter twisting Hamiltonian around  axis in absence of magnetic field, the system initially must be in a tensor product of  or  eigenstates. Also, the system initially in the  eigenstates under the influence of one-axis counter twisting Hamiltonian around  axis in absence of a magnetic field is not entangled, but, under the influence of one-axis counter twisting Hamiltonian around  axis in presence of a magnetic field in  direction the entanglement for this state becomes maximum. For all states, the frequency of entanglement is an increasing function of the magnetic field.

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References

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History

  • Receive Date: 23 November 2020
  • Revise Date: 23 January 2021
  • Accept Date: 04 April 2021

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