Unexpected magnetic properties in an ultra-thin transverse Ising film with bond or site dilution at surfaces

The phase diagrams and magnetizations in a nanoscaled thin film with bond and site dilutions at the surfaces, described by the transverse Ising model, are investigated by the use of the effective field theory with correlations. We find a number of unexpected novel phenomena in them, when the ratio between the transverse field at the surfaces and the transverse field in the inner layer takes a large value; such as the increase of transition temperature, even when the dilution with nonmagnetic atoms at the surfaces is increased.