  Entangled solid state systems have gained a great deal of attention due to
their fruitful applications in modern quantum technologies. Herein, detection
of entanglement content from experimental magnetic susceptibility and specific
heat data is reported for NH4CuPO4.H2O in its solid state crystalline form.
NH4CuPO4.H2O is a prototype of Heisenberg spin 1/2 dimer system. Temperature
dependent magnetic susceptibility and specific data are fitted to an isolated
dimer model and the exchange coupling constant is determined. Field dependent
magnetization isotherms taken at different temperatures are plotted in a three
dimensional plot. Subsequently, entanglement is detected both from
susceptibility and specific heat through two different entanglement measures;
entanglement witness and entanglement of formation. The temperature evolution
of entanglement is studied and the critical temperature is determined up to
which entanglement exists. Temperature dependent nature of entanglement
extracted from susceptibility and specific heat shows good consistency with
each other. Moreover, the field dependent entanglement is also investigated.
