Quantum Lunch: Topological edge states are monogamous

Speaker: Konstantinos Meichanetzidis, Center for Topological Quantum Information (Leeds).

Abstract:We propose an alternative approach to assessing topologically induced edge states in free and interacting fermionic systems. We do so by focussing on the fermionic covariance matrix of the ground state. This matrix is often tractable either analytically or numerically and it captures the relevant correlations. By invoking the concept of monogamy of entanglement we show that highly entangled states supported across a system bi-partition are largely disentangled from the rest of the system. We then define an entanglement qualifier that identifies the presence of topological edge states in terms of singular values of the covariance matrix. We demonstrate the versatility of this qualifier by applying it to free and interacting fermionic topological systems.

Based on: Konstantinos Meichanetzidis, Jens Eisert, Mauro Cirio, Ville Lahtinen, Jiannis K. Pachos, Diagnosing Topological Edge States via Entanglement Monogamy, Phys. Rev. Lett. 116, 130501 (2016), arXiv:1511.04459.