Effective field approach to the Ising film in a transverse field

We study the phase transitions of the spin1 2 Ising film in a transverse field within the framework of the effective field theory. We evaluate the critical temperature of the film as a function of the exchange interactions, the transverse field and the film thickness. We find that, if the ratio of the surface exchange interactions to the bulk ones R = Js/J is smaller than a critical value Rc, the critical temperature Tc/J of the film is smaller than the bulk critical temperature TB c /J and approaches T B c /J as R increases further. On the other hand, if R > Rc, Tc/J is larger than both the bulk TB c /J and the surface T S c /J critical temperatures of the corresponding semi-infinite system, and approaches T S c /J as R increases further. P.A.C.S.: 75.70.Ak, 75.40.Cx, 05.50.+q