Maximally entangled mixed states: do they exist?

Prof.

Julio

de Vicente

Universidad Carlos III de Madrid

June 12, 2024 2:30 PM

Zoom: https://us06web.zoom.us/j/81067604076?pwd=ZcepRfhmZa6E5njcATHrr8BXKSAUto.1

ID: 810 6760 4076

Code: 628975

Abstract

One of the milestones of entanglement theory is the existence of a maximally entangled state. This means that this is the most useful state one can prepare for all entanglement-based applications of quantum information theory irrespectively of the particular task to be implemented and it also serves as a gold standard to measure the quality of any other entangled state. However, the maximally entangled state is pure, while in practice one always deals with mixed states due to the unavoidable effect of noise. A natural question is then whether a notion of maximally entangled mixed state is possible under some reasonable constraint in the degree of mixedness. In particular, it has been long asked whether there is a maximally entangled state for a fixed spectrum since this characterizes the states that can be prepared from a noisy separable input by Hamiltonian dynamics. In this talk I will provide the solution to this problem.