Generalizing the Quantum Information Model for Dynamic Diffraction

TL;DR

This paper extends a quantum information model of dynamical diffraction to complex geometries and imperfections, aligning with experimental data and surpassing the limitations of standard DD theory in neutron optics.

Contribution

It introduces a universal quantum information-based model for dynamical diffraction that accounts for complex geometries and imperfections, aligning with experimental results.

Findings

Model is mathematically equivalent to Takagi-Taupin equations in certain limits.

Model can be extended to Bragg and Laue-Bragg geometries.

Demonstrates universality and potential for complex scenario modeling.

Abstract

The development of novel neutron optics devices that rely on perfect crystals and nano-scale features are ushering a new generation of neutron science experiments, from fundamental physics to material characterization of emerging quantum materials. However, the standard theory of dynamical diffraction (DD) that analyzes neutron propagation through perfect crystals does not consider complex geometries, deformations, and/or imperfections which are now becoming a relevant systematic effect in high precision interferometric experiments. In this work, we expand upon a quantum information (QI) model of DD that is based on propagating a particle through a lattice of unitary quantum gates. We show that the model output is mathematically equivalent to the spherical wave solution of the Takagi-Taupin equations when in the appropriate limit, and that the model can be extended to the Bragg as well as the Laue-Bragg geometry where it is consistent with experimental data. The presented results demonstrate the universality of the QI model and its potential for modeling scenarios that are beyond the scope of the standard theory of DD.