Using the trace minimization algorithm, we carried out an exact calculation of entanglement in a 19-site two-dimensional transverse Ising model. This model consists of a set of localized spin-12 particles in a two-dimensional triangular lattice coupled through exchange interaction J and subject to an external magnetic field of strength h. We demonstrate, for such a class of two-dimensional magnetic systems, that entanglement can be controlled and tuned by varying the parameter λ=h/J in the Hamiltonian and by introducing impurities into the systems. Examining the derivative of the concurrence as a function of λ shows that the system exhibits a quantum phase transition at about λc=3.01, a transition induced by quantum fluctuations at the absolute zero of temperature.
|Journal||Physical Review A - Atomic, Molecular, and Optical Physics|
|Publication status||Published - 23 Feb 2010|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics