Two-dimensional matter-wave interferometer, rotational dynamics, and spin contrast

TL;DR

This paper explores a two-dimensional matter-wave interferometer using NV-centred nanodiamonds, analyzing rotational dynamics and magnetic field effects to enhance spin contrast and create spatial superpositions.

Contribution

It introduces a novel two-dimensional interferometry scheme combining spatial and rotational dynamics with magnetic fields for improved quantum control.

Findings

External rotation enhances spin contrast via gyroscopic stability.

The scheme achieves a spatial superposition of ~0.21 μm in under 0.013 seconds.

Analysis of Euler-angle dynamics addresses stability and the Humpty-Dumpty problem.

Abstract

We investigate a two-dimensional matter-wave interferometer where both spatial and rotational dynamics of a nanoparticle are intertwined in closing the one-loop interferometer in the Stern-Gerlach type setup. We consider the spin-contrast of the nitrogen-vacancy (NV) centred nanodiamond in combination with a two-dimensional magnetic field setup to extend the one-dimensional Stern--Gerlach interferometry. We analyse the dynamical motion along with the rigid rotation under the influence of the external magnetic field. Regarding rotation, we incorporate Euler-angle dynamics to analyse the stability of rotational degrees of freedom and their influence on the spin contrast to address the Humpty-Dumpty problem. We show that by imparting external rotation provides the gyroscopic stability to the liberating mode of the NV-spin and hence helps to improve the contrast. Our scheme creates a tiny spatial superposition of size $\sim 0.21~{\rm \mu m}$ for mass $m=10^{-17}$kg in less than $t\sim 0.013$s.