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Owen Lailey

Publications and source records attributed to Owen Lailey.

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A unified quantum random walk model for internal crystal effects in dynamical diffraction

The theory of dynamical diffraction (DD) in perfect crystals is the backbone of high-precision neutron and X-ray diffraction experiments, enabling accurate determination of crystal structure factors and the realization of perfect crystal interferometers. In practice, however, real crystals exhibit deformations and imperfections, including surface roughness, defects, temperature gradients, angled crystal faces, and curvature, that degrade interferometer performance and are difficult to model using conventional DD theory, particularly in complex geometries. To address these challenges, a quantum information (QI) model for DD has been under development, with demonstrated experimental agreement for both ideal crystals and in the presence of some imperfections such as surface roughness and defects. Here, we present a unified quantum random walk model that is now suitable for reproducing all established DD effects. We demonstrate this by incorporating a broad range of internal crystal effects influencing DD intensity distributions, including linear temperature gradients, the DD Talbot effect, and angled or miscut crystals. These results establish the QI model as a comprehensive and flexible framework for experimental analysis, as well as for the design of next-generation perfect crystal neutron interferometers and neutron optical components, such as condensing monochromators.

physics.app-ph

A perfect crystal neutron loop cavity

Coherent control of neutrons via Bragg diffraction forms the foundation of perfect crystal neutron interferometry, facilitating both fundamental tests of quantum mechanics and applications in quantum information science. In cavity geometries, perfect crystals enable neutron confinement and have been employed in precision measurements of spin-orbit interactions and for neutron electric dipole moment (nEDM) searches. However, in these conventional configurations, neutrons undergo a single pass through the crystal geometry, placing a physical constraint on both crystal and in-flight interaction times and measurement sensitivity. In this work, we introduce a neutron loop cavity that coherently recirculates neutrons through repeated Bragg reflections between perfect silicon crystal blades. This structure is predicted to achieve a neutron survival probability of $\sim64~\%$ for 10,000 Bragg reflections, corresponding to confinement times on the order of seconds. We propose a Schwinger interaction measurement that achieves a $\pi$ spin rotation in 800 Bragg reflections, representing more than a tenfold improvement in sensitivity over recent measurements. Further applications include high-sensitivity nEDM searches targeting the $10^{-27}~$e$\cdot$cm scale, as well as competitive experimental tests of neutron parity violation, the neutron lifetime, and the quantum Zeno effect with neutrons.

physics.ins-det

A generalized K-space coherent averaging method for engineering lattices of spin-orbit beams

Spin-orbit beams, in which the orbital angular momentum degree of freedom is coupled to a two-level system such as polarization of light or spin in electrons and neutrons, have gained significant interest for their unique propagation properties and potential applications in imaging, material characterization, optical trapping, and quantum information processing. In this work we introduce a method for generating and engineering two-dimensional lattices of such spin-orbit beams based on coherent averaging in k-space. By programming the angle, amplitude, and polarization of a set of input beams we obtain precise control over lattice geometry and period, as well as the orbital and radial degrees of freedom inside each unit cell. We explore both electromagnetic and matter wave implementations, and we experimentally demonstrate the generation and characterization of a micron-scale optical hexagonal lattice with well defined orbital and radial numbers in each unit cell. The described methods provide a robust and general method of generating and controlling structured waves such as optical skyrmions and matter wave implementations of orbit and spin-orbit beams.

physics.optics

Multimode structured neutron beams

The experimental realization of neutron orbital angular momentum (OAM) states and neutron Airy beams has opened new avenues for structured neutron science in both materials characterization and fundamental physics. These additional degrees of freedom in scattering experiments enable the exploration of selection rules for neutrons, the analysis of scattering properties in topological materials, and the generation of auto-focusing neutron beams. In the effort to enhance the amount of spatial and angular-momentum information retrievable from a single measurement, and to overcome current phase-grating efficiency limits, here we demonstrate multimode structured neutron beams that enable simultaneous access to multiple, well-defined OAM modes, and to hybrid combinations of OAM and Airy states. This multimode approach, analogous to wavelength- or OAM-multiplexing in optics, facilitates the efficient investigation of material scattering properties and nuclear interactions with a neutron source composed of a discretized OAM spectrum.

physics.app-ph

Quantitative diagnosis of amyloid without Congo red staining using polarized light microscopy

Amyloidosis is a protein misfolding disease caused by the deposition of large, insoluble aggregates (amyloid fibrils) of protein in a tissue, which has been associated with various conditions, such as lymphoid disorders, Alzheimer's disease, diabetes mellitus type 2, chronic inflammatory processes, and cancers. Amyloid fibrils are commonly diagnosed by qualitative observation of green birefringence from Congo red stained biopsy tissue samples under polarized light, a technique that is limited by lack of specificity, dependence on subjective interpretation, and technical constraints. Studies emphasize the utility of quantitative polarized light microscopy (PLM) methodology to diagnose amyloid fibrils in Congo red stained tissues. However, while Congo red enhances the intrinsic birefringence of amyloid fibrillar structures, there are significant disadvantages such as the appearance of multiple non-green colors under polarized light and binding to other structures, which may result in misdiagnoses with Congo red dye and inconclusive explanations. In this work, we present an improved PLM methodology for quantitative detection of amyloid fibrils without requiring Congo red staining. We perform PLM measurements on four tissues: abdominal subcutaneous tissue biopsy, duodenal biopsy, thyroid biopsy, and breast biopsy, both with Congo red stain and H\&E stain, and through Fourier analysis quantify birefringence, birefringent axis orientation, dichroism, optical activity, and relative amyloid density. These results emphasize a quantitative analysis for amyloid diagnosis rooted in Fourier signal harmonics that does not require Congo red dye and paves the way for rapid, simple, and accurate diagnosis of amyloid fibrils.

physics.med-ph

Generation of neutron Airy beams

The Airy wave packet is a solution to the potential-free Schrodinger equation that exhibits remarkable properties such as self-acceleration, non-diffraction, and self-healing. Although Airy beams are now routinely realized with electromagnetic waves and electrons, the implementation with neutrons has remained elusive due to small transverse coherence lengths, low fluence rates, and the absence of neutron lenses. In this work, we overcome these challenges through a holographic approach and present the first experimental demonstration of neutron Airy beams. The presented techniques pave the way for fundamental physics studies with Airy beams of non-elementary particles, the development of novel neutron optics components, and the realization of neutron Airy-vortex beams.

physics.app-ph

Small-angle scattering interferometry with neutron orbital angular momentum states

Access to the neutron orbital degree of freedom has been enabled by the recent actualization of methods to prepare and characterize neutron helical waves carrying orbital angular momentum (OAM) at small-angle neutron scattering (SANS) facilities. This provides new avenues of exploration in fundamental science experiments as well as in material characterization applications. However, it remains a challenge to recover phase profiles from SANS measurements. We introduce and demonstrate a novel neutron interferometry technique for extracting phase information that is typically lost in SANS measurements. An array of reference beams, with complementary structured phase profiles, are put into a coherent superposition with the array of object beams, thereby manifesting the phase information in the far-field intensity profile. We demonstrate this by resolving petal-structure signatures of helical wave interference for the first time: an implementation of the long-sought recovery of phase information from small-angle scattering measurements.

physics.app-ph