Estimation of entanglement and quantum discord in a low dimensional quantum system

Quantum correlations like entanglement is considered to be the most fundamental and essential physical resource for quantum protocols. Thus, quantification of entanglement in real macroscopic systems would be of immense importance. In my talk, I will address experimental detection and hence quantification of entanglement in real macroscopic spin system using macroscopic observables likes magnetic susceptibility and heat capacity, both as a function of temperature and magnetic field. For this study, we considered a one dimensional spin chain (Cu(NO3)2. 2.5H2O) as our model system. Our results show good agreement with the theoretical predictions reported in the literature. We captured quantum phase transition (QPT) in our system by varying heat capacity beyond critical field value and fitted them to the corresponding theoretical curve with a good match. Thereafter, we also studied entanglement in the vicinity of QPT. Quantum discord (QD), another form of quantum correlation has been a matter of intense study in recent times. We will also discuss the quantification of QD in the same system as mentioned above. Here also experimental results matches well with the theoretical predictions.