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تسجيل مستخدم جديدEntanglement in a second order quantum phase transition
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We consider a system of mutually interacting spin 1/2 embedded in a transverse magnetic field which undergo a second order quantum phase transition. We analyze the entanglement properties and the spin squeezing of the ground state and show that, contrarily to the one-dimensional case, a cusp-like singularity appears at the critical point $lambda_c$, in the thermodynamic limit. We also show that there exists a value $lambda_0 geq lambda_c$ above which the ground state is not spin squeezed despite a nonvanishing concurrence.
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