Structured Beams as Quantum Probes

This thesis describes several projects under the common theme of generating and manipulating the spatial quantum phase structure of matter and electromagnetic waves. Experiments dealing with the following topics are addressed: perfect crystal neutron interferometry, far-field phase-grating moire interferometry, orbital angular momentum (OAM), spin-orbit states, and lattices of spin-orbit states. The first focus of the thesis is describing the work related to the construction of a new beamline dedicated to quantum information related neutron interferometry experiments at the National Institute of Standards and Technology's Center for Neutron Research. This includes the development of the necessary environmental isolation, phase stability, and temperature isolation mechanisms; and the installation and optimization of spin polarization elements. The new beamline is now operational and it is currently one of only three neutron interferometry facilities in the world. The second focus of the thesis is to describe the development and characterization of far-field phase-grating moire neutron interferometry. This technique enables studies that are complimentary to those of perfect crystal neutron interferometry experiments. It may be used to probe structured materials and characterize neutron interactions with potential gradients. A two phase-grating moire neutron interferometer was developed, characterized, and optimized. This setup was then employed to probe the microstructure of a monodisperse suspension of 2 um diameter polystyrene spheres. Furthermore, a three phase-grating moire neutron interferometer was developed and characterized. This unique setup promises a wide range of impactful experiments from far-field imaging of material substructure to fundamental physics. The third focus of the thesis is to describe neutron OAM. These experiments revolve around the preparation and characterization of an azimuthally varying phase profile. The demonstration of neutron OAM using a perfect crystal neutron interferometer is described, where a spiral phase plate was used to induce OAM in one of the paths of the interferometer. Furthermore, a modified setup was used to perform neutron holography of a macroscopic object which induces an azimuthally varying phase profile. These methods provide a new tool for interferometric testing of neutron optics and the characterization of coherence of neutron beams. The last focus of the thesis is to describe matter wave and optical spin correlated OAM (spin-orbit) states. Methods to prepare neutron spin-orbit states via special geometries of magnetic fields are proposed. The preparation, entanglement characterization, and proposed experimental verification of such states are described in detail. Furthermore, a method which is capable of preparing lattices of optical and neutron spin-orbit states is introduced and described. This method utilizes novel optical and neutron devices and it is based on coherent averaging and spatial control methods borrowed from nuclear magnetic resonance. The experimental preparation and characterization of optical lattices of spin-orbit states is described in detail

Simple filter microchip for rapid separation of plasma and viruses from whole blood

Sample preparation is a significant challenge for detection and sensing technologies, since the presence of blood cells can interfere with the accuracy and reliability of virus detection at the nanoscale for point-of-care testing. To the best of our knowledge, there is not an existing on-chip virus isolation technology that does not use complex fluidic pumps. Here, we presented a lab-on-a-chip filter device to isolate plasma and viruses from unprocessed whole blood based on size exclusion without using a micropump. We demonstrated that viruses (eg, HIV) can be separated on a filter-based chip (2-μm pore size) from HIV-spiked whole blood at high recovery efficiencies of 89.9% ± 5.0%, 80.5% ± 4.3%, and 78.2% ± 3.8%, for viral loads of 1000, 10,000 and 100,000 copies/mL, respectively. Meanwhile, 81.7% ± 6.7% of red blood cells and 89.5% ± 2.4% of white blood cells were retained on 2 μm pore–sized filter microchips. We also tested these filter microchips with seven HIV-infected patient samples and observed recovery efficiencies ranging from 73.1% ± 8.3% to 82.5% ± 4.1%. These results are first steps towards developing disposable point-of-care diagnostics and monitoring devices for resource-constrained settings, as well as hospital and primary care settings

Noise refocusing in a five-blade neutron interferometer

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. The following article appeared in Nsofini, J., Sarenac, D., Ghofrani, K., Huber, M. G., Arif, M., Cory, D. G., & Pushin, D. A. (2017). Noise refocusing in a five-blade neutron interferometer. Journal of Applied Physics, 122(5), 054501. doi:10.1063/1.4996866 and may be found at https://dx.doi.org/10.1063/1.4996866We provide a quantum information description of a proposed five-blade neutron interferometer geometry and show that it is robust against low-frequency mechanical vibrations and dephasing due to the dynamical phase. The extent to which the dynamical phase affects the contrast in a neutron interferometer is experimentally shown. In our model, we consider the coherent evolution of a neutron wavepacket in an interferometer crystal blade and simulate the effect of mechanical vibrations and momentum spread of the neutron through the interferometer. The standard three-blade neutron interferometer is shown to be immune to dynamical phase noise but prone to noise from mechanical vibrations, and the decoherence free subspace four-blade neutron interferometer is shown to be immune to mechanical vibration noise but prone to noise from the dynamical phase. Here, we propose a five-blade neutron interferometer and show that it is immune to both low-frequency mechanical vibration noise and dynamical phase noise.National Science Foundation: PHY-0245679Canada Excellence Research Chairs, Government of Canada: 215284Natural Sciences and Engineering Research Council of CanadaCanada First Research Excellence Fun

Neutron Interferometry at the National Institute of Standards and Technology

Neutron interferometry has proved to be a very precise technique for measuring the quantum mechanical phase of a neutron caused by a potential energy difference between two spatially separated neutron paths inside interferometer. The path length inside the interferometer can be many centimeters (and many centimeters apart) making it very practical to study a variety of samples, fields, potentials, and other macroscopic medium and quantum effects. The precision of neutron interferometry comes at a cost; neutron interferometers are very susceptible to environmental noise that is typically mitigated with large, active isolated enclosures. With recent advances in quantum information processing especially quantum error correction (QEC) codes we were able to demonstrate a neutron interferometer that is insensitive to vibrational noise. A facility at NIST's Center for Neutron Research (NCNR) has just been commissioned with higher neutron flux than the NCNR's older interferometer setup. This new facility is based on QEC neutron interferometer, thus improving the accessibility of neutron interferometry to the greater scientific community and expanding its applications to quantum computing, gravity, and material research.Natural Sciences and Engineering Research Council of Canad

Spin-orbit states of neutron wave packets

© 2016 American Physical Society, https://dx.doi.org/10.1103/physreva.94.013605We propose amethod to prepare an entangled spin-orbit state between the spin and the orbital angular momenta of a neutron wave packet. This spin-orbit state is created by passing neutrons through the center of a quadrupole magnetic field, which provides a coupling between the spin and orbital degrees of freedom. A Ramsey-fringe-type measurement is suggested as a means of verifying the spin-orbit correlations.Natural Sciences and Engineering Research Council of CanadaNational Institute of Standards and Technolog

Holography with a neutron interferometer

© 2016 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reserved.We use a Mach-Zehnder interferometer to perform neutron holography of a spiral phase plate. The object beam passes through a spiral phase plate, acquiring the phase twist characteristic of orbital angular momentum states. The reference beam passes through a fused silica prism, acquiring a linear phase gradient. The resulting hologram is a fork dislocation image, which could be used to reconstruct neutron beams with various orbital angular momenta. This work paves the way for novel applications of neutron holography, diffraction and imaging.Canada Excellence Research Chairs, Government of Canada: 215284National Institute of Standards and TechnologyNatural Sciences and Engineering Research Council of Canada: RGPIN-418579U.S. Department of Energy: DE-FG02-97ER41042National Science Foundation: PHY-1307426, PHY-1205342Collaborative Research and Training Experience (CREATE) program: 41406

Three Phase-Grating Moire Neutron Interferometer for Large Interferometer Area Applications

We demonstrate a three phase-grating moire neutron interferometer in a highly intense neutron beam as a robust candidate for large area interferometry applications and for the characterization of materials. This novel far-field moire technique allows for broad wavelength acceptance and relaxed requirements related to fabrication and alignment, thus circumventing the main obstacles associated with perfect crystal neutron interferometry. We observed interference fringes with an interferometer length of 4 m and examined the effects of an aluminum 6061 alloy sample on the coherence of the system. Experiments to measure the autocorrelation length of samples and the universal gravitational constant are proposed and discussed.U.S. Department of CommerceNational Institute of Standards and TechnologyCanada Excellence Research Chairs, Government of CanadaNatural Sciences and Engineering Research Council of CanadaU.S. Department of EnergyCanada First Research Excellence Fun