Creating two-qudit maximally entangled quantum link through bulk

TL;DR

This paper proposes a method to generate maximally entangled two-qudit links between distant nodes using a spin-s bulk system, applicable at low temperatures and with various interaction models, enhancing quantum communication capabilities.

Contribution

It introduces a novel setup for creating high-quality entanglement between distant qudits via spin-s bulk systems, including dynamic evolution without equilibrium constraints.

Findings

Maximal entanglement achievable with Heisenberg and BBQ models.

Entanglement increases with the size of the spin-s bulk.

Protocols remain effective with unequal spin quantum numbers.

Abstract

We design a set-up for creating maximally entangled two-qudit links between distant nodes which are weakly coupled with interacting spin-s bulk (processor). We exhibit that such quantum links of arbitrary spin quantum number can be formed when the system is prepared at a very low temperature. We find that the Heisenberg and the bilinear-biquadratic (BBQ) spin-s models are the potential candidates to achieve the maximal entanglement in equilibrium. By eliminating the equilibrium requirement, we show that a completely polarized state in the bulk and a suitable qudit state in the link can evolve over time to produce a highly entangled state, as per the BBQ Hamiltonian with nearest- and next-nearest neighbor interactions. When the number of sites in the bulk grows, so does the maximum entanglement produced in dynamics. Further, both the static and the dynamical protocols presented here remain efficient even if the spin quantum numbers of the bulk and the connection are unequal.