Entanglement and non-factorizability

Author-Highlights
• We consider several notions of entanglement.
• We argue that on the best of them, indistinguishable fermions are not always entangled.
• We present a way of representing fermionic states that allows us to maintain a link between entanglement and non-factorizability.

Quantum mechanics tells us that states involving indistinguishable fermions must be antisymmetrized. This is often taken to mean that indistinguishable fermions are always entangled. We consider several notions of entanglement and argue that on the best of them, indistinguishable fermions are not always entangled. We also present a simple but unconventional way of representing fermionic states that allows us to maintain a link between entanglement and non-factorizability.