Entanglement witness for spin glass

We derived the entanglement witness (EW) in the Ising model for both the magnetic susceptibility and specific heat capacity of a spin glass. The magnetic susceptibility EW curve for LiHoxY 1−xF4 is formulated and compared with the existing data of LiHo0.167Y 0.833F4 to identify the entangled and unentangled regions. The EW for the magnetic susceptibility was found to cut the cusp of the experimental result at a critical temperature of about 0.2669 K. The specific heat capacity EW curve for CuxMn is formulated and compared with the existing data of Cu0.279 Mn to identify the entangled and unentangled region for the various applied magnetic field B. With increasing B, the critical temperature where the EW curve intersects the experimental data, increases as well.