Like BPS D3 brane, the non-supersymmetric (non-susy) D3 brane of type IIB
string theory is also known to have a decoupling limit and leads to a
non-supersymmetric AdS/CFT correspondence. The throat geometry in this case
represents a QFT which is neither conformal nor supersymmetric. The `black'
version of the non-susy D3 brane in the decoupling limit describes a QFT at
finite temperature. Here we first compute the entanglement entropy for small
subsystem of such QFT from the decoupled geometry of `black' non-susy D3 brane
using holographic technique. Then we study the entanglement thermodynamics for
the weakly excited states of this QFT from the asymptotically AdS geometry of
the decoupled `black' non-susy D3 brane. We observe that for small subsystem
this background indeed satisfies a first law like relation with a universal
(entanglement) temperature inversely proportional to the size of the subsystem
and an (entanglement) pressure normal to the entangling surface. Finally we
show how the entanglement entropy makes a cross-over to the thermal entropy at
high temperature.Comment: 13 pages, 0 figures; v2: more clarifications added, version to appear
in Phys Lett