Universality of Entanglement Sudden Death
- Cristhiano Duarte (Universidade Federal de Minas Gerais, Brazil)
Following the definition of entanglement as a resource for non-local tasks, as a consequence being quantified, the time evolution of this quantity has been the subject of intense interest. For instance, for practical implementations of quantum information protocols, which require certain quantity of entanglement, it is valuable, therefore, to understand how the amount of such a resource behaves in time. One peculiar characteristic of entanglement dynamics that has recently drawn a great deal of attention is the possibility of an initially entangled state to lose all its entanglement in a finite time, instead of only asymptotically. Such an aspect was initially called entanglement sudden death, or finite time disentanglement (FTD).
It has already been explored how typical this phenomenon is when one varies the initial states for several paradigmatic dynamics of two qubits and two harmonic oscillators. In this seminar I would like to discuss results, and some open questions, regarding the counterpart of this point of view, i.e. given a dynamics for a composite quantum system, should one expect to find some initially entangled state which exhibits FTD? As we will see, the answer is typically affirmative, in the sense that almost all quantum dynamical mappings do exhibit FTD, and its explanation relies strongly on the topology of the space state.