Speed of evolution in entangled fermionic systems

TL;DR

This paper investigates the speed at which entangled fermionic systems evolve towards orthogonal states, analyzing quantum speed limits and their relation to entanglement, with broader implications for similar quantum systems.

Contribution

It characterizes quantum speed limits in fermionic systems and explores their connection to entanglement, extending the analysis to a wider class of 6-dimensional states.

Findings

Orthogonality times are characterized for fermionic systems.

The relation between evolution speed and entanglement is nuanced but observable.

Results apply to a broad family of quantum states beyond fermions.

Abstract

We consider the simplest identical-fermion system that exhibits the phenomenon of entanglement (beyond exchange correlations) to analyze its speed of evolution towards an orthogonal state, and revisit the relation between this latter and the amount of fermionic entanglement. A characterization of the quantum speed limit and the orthogonality times is performed, throwing light into the general structure of the faster and the slower states. Such characterization holds not only for fermionic composites, but apply more generally to a wide family of 6-dimensional states, irrespective of the specific nature of the system. Further, it is shown that the connection between speed of evolution and entanglement in the fermionic system, though more subtle than in composites of distinguishable parties, may indeed manifest for certain classes of states.