Multipartite entangled states in particle mixing

Abstract

In the physics of flavor mixing, the flavor states are given by superpositions of mass eigenstates. By using the occupation number to define a multiqubit space, the flavor states can be interpreted as multipartite mode-entangled states. By exploiting a suitable global measure of entanglement, based on the entropies related to all possible bipartitions of the system, we analyze the correlation properties of such states in the instances of three- and four-flavor mixing. Depending on the mixing parameters, and, in particular, on the values taken by the free phases, responsible for the CP-violation, entanglement concentrates in preferred bipartitions. We quantify in detail the amount and the distribution of entanglement in the physically relevant cases of flavor mixing in quark and neutrino systems. By using the wave packet description for localized particles, we use the global measure of entanglement, suitably adapted for the instance of multipartite mixed states, to analyze the decoherence induced by the free evolution dynamics on the quantum correlations of stationary neutrino beams. We define a decoherence length as the distance associated with the vanishing of the coherent interference effects among massive neutrino states. We investigate the role of the CP-violating phase in the decoherence process.Comment: 18 pages, 7 figure

Entanglement in neutrino oscillations

“…It is important to remark that, although dealing with similar physical systems, both the framework and the aim of the present paper differ substantially from those of ref. [16]. In the latter, by exploiting the wave packet approach, the multipartite entanglement, associated with the multiqubit space of mass modes, has been analyzed in connection with the "decoherence" effects induced by free evolution.…”

“…In the relativistic limit, the exact QFT flavor states reduce to the usual Pontecorvo flavor states, which define the flavor modes as legitimate and physically well-defined individual entities. Mode entanglement can thus be defined and studied in analogy with the static case [16].…”

Characterization of Unruh channel in the context of open quantum systems

“…Here, in particular, we study the Unruh effect [10,11,16] which predicts thermal like effects from observing uniform acceleration of the Minkowski vacuum. This has attracted intense interest [17][18][19][20][21][22][23][24][25][26][27] and has emerged as a natural quest in the direction of relativistic quantum information [28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”

Maximal correlation between flavor entanglement and oscillation damping due to localization effects

“…Hereafter entanglement of formation (E F ) and logarithmic negativity (E N ) are reported as quantifiers for quantum correlations between mass fields in the scenario of three-flavor neutrino mixing. Neutrino mass-eigenstates are then supposed to compound a 3-dim orthonormal basis as to make possible the description of each mass-eigenstate as a three-qubit state [14]. It supports the picture of flavor states described by entangled states such that the above mentioned quantum correlations can be computed between mass modes [14].…”

“…Entanglement is a natural quantum correlation that arises as consequence of the superposition principle in composite quantum systems [13,14]. In particle physics, quantum entanglement has already been considered for quantifying the particle mixing in two-body systems like K 0 K 0 and B 0 B 0 states produced in electron-positron annihilations [15,16].…”