NOON States via Quantum Walk of Bound Particles

TL;DR

This paper proposes a method to generate NOON states in lattice systems by using quantum walks of bound particles with local impurities, enhancing quantum interferometry capabilities.

Contribution

It introduces a novel scheme employing local impurities to split bound particle wave-packets, enabling distant NOON state creation in lattice models.

Findings

Effective model for bound particle propagation in Bose-Hubbard chains.

Impurities improve transfer fidelity and robustness against decoherence.

Potential applications in quantum-enhanced atomic interferometry.

Abstract

Tight-binding lattice models allow the creation of bound composite objects which, in the strong-interacting regime, are protected against dissociation. We show that a local impurity in the lattice potential can generate a coherent split of an incoming bound particle wave-packet which consequently produces a NOON state between the endpoints. This is non trivial because when finite lattices are involved, edge-localisation effects make their use for non-classical state generation and information transfer challenging. We derive an effective model to describe the propagation of bound particles in a Bose-Hubbard chain. We introduce local impurities in the lattice potential to inhibit localisation effects and to split the propagating bound particle, thus enabling the generation of distant NOON states. We analyse how minimal engineering transfer schemes improve the transfer fidelity and we quantify the robustness to typical decoherence effects in optical lattice implementations. Our scheme potentially have an impact on quantum-enhanced atomic interferometry in a lattice.