#### Alladi Ramakrishnan Hall

#### Manifestation of Entanglement in Quantum Foundations and Thermodynamics

#### Arpan Das

##### IOP - Bhubaneswar

*This talk is mainly divided into two parts. In the first part,*

I will be talking about Entanglement, Bell nonlocality and explore the

interplay between them in the multipartite scenario. Specifically, I

constructed new Bell inequalities for multiqubit system mainly designed

for generalized GHZ states, which do not violate any correlation Bell

inequalities (for two dichotomic measurements for each party) for a

certain parameter range. Our motivation was to have Bell inequalities,

which would show a violation for every generalized GHZ state. We also

studied different aspects of these inequalities including their

connections with multipartite entanglement. I will also be discussing a

QIP protocol called co-operative QKD and the structure of the resource

states for this protocol.

In the second part of my talk, I will be discussing the role of Quantum

correlations in Quantum Thermodynamics, which is still far from fully

understood. Specifically, I consider the role of entanglement for a

single temperature quantum heat engine without feedback control,

introduced recently by Talkner and Kim [Phys. Rev. E 96, 022108 (2017)].

We take the working medium of the engine to be a 1-dim Heisenberg model

of two spins. We calculate the efficiency of the engine undergoing a

cyclic process at a single temperature and show that for a coupled

working medium the efficiency can be higher than that of an uncoupled

one.

Done