Persistent fermionic entanglement under decoherence

Abstract

We consider a system of two indistinguishable fermions (with four accessible states each) that suffers decoherence without dissipation due to its coupling with a global bosonic bath at a fixed temperature. Using an appropriate measure of fermionic entanglement, we identify families of two-fermion states whose entanglement persists throughout the evolution, either fully or partially, despite the noisy effects of the interaction with the bath, and independently of its temperature. The identified resilience to decoherence provides valuable insights into the entanglement dynamics of open systems of indistinguishable fermions, and into the conditions under which long-lived entanglement emerges under more general decoherence channels.