Determination of Tripartite Entanglement: An Approach to One-Step Double Photoionization of Xenon Atom

Quantum entanglement holds the key to a revolution in information processing.This paper investigates the entanglement characteristics of tripartite states of two electronic qubits and an ionic qubit produced by single-step double photoionization (DPI) from a Xeon atom after absorption of a single photon, without observing spin orbit interaction (SOI). DPI is the most natural processes for simultaneously producing two electrons in continuum in a single step.  The dimension of the Hilbert space of the qudit depends upon the electronic state of the residual photoion Xe2+. Russel-Salunders coupling (L-S coupling) is applicable in absence of SOI. We consider Peres-Horodecki condition and negativity as an estimation of entanglement. With L-S coupling, all of the properties of a qubit-qudit system can be predicted simply by knowing the spins of the target atom, the residual photoion, the emitted electrons, and the polarisation state of incident photons.