The Quantum State of a Virtual Particle

Gonçalo M. Quinta

Published 2022-11-10Version 1

We show that a virtual fermion, despite being unobservable, can be described by a quantum state in momentum space under certain conditions. We prove that such a state can be regarded as a 2-qubit mixed state, where the qubits are physically associated to particle type and spin. We show that the mixed state is a separable combination of entangled pure states, whose entanglement is proportional to the transverse momentum norm. Lastly, we show that this state is always thermal. These findings represent a new connection between quantum field theory, quantum information and quantum thermodynamics.