Research

• Graph state assisted deterministic entanglement concentration: Entanglement concentration refers to enriching the shared entanglement between parties by using up many copies of weaker resource states. We devised a measurement strategy based on graph states that can result in entanglement concentration which always succeeds. The concentration results in a maximally entangled pair in the asymptotic limit such that a near perfect teleportation can be achieved with finite weaker resources.

• Localizable entanglement in noisy stabilizer states: Stabilizer states and graph states are important classes of quantum states used for error correction protocols and many more applications. We devise a protocol to localize entanglement in noisy stabilizer states which arise naturally as one tries to create such states in laboratories. 

• Topological quantum phase transitions: Topological phases of matter have attracted interest in recent times. As one perturbs such phases, there can be quantum phase transition from topological to non-topological phases. We study such a phase transition with the previously developed tool to localize entanglement.

• Quasi 1D lattices and quantum phase transitions: In 2D systems, the nature of boundary conditions can largely affect the robustness of the system against local perturbations. We observe such an enhancement in robustness in the topological quantum phase transition of the celebrated Kitaev model. 

• Bounds on localizable entanglement: Entanglement is an important resource for many quantum information protocols. We study interesting entanglement properties of such resource states.  

• Heisenberg model on 2D lattices and quantum state transfer: The isotropic Heisenberg model on a 2D lattice is an important quantum many-body model. We show that under certain conditions, such a system can be effectively described by a 1D model. We also propose a method to transfer quantum states along different points on a 2D lattice.