Presentation on theme: "Matter wave interferomery with poorly collimated beams x [µm] Ben McMorran, Alex Cronin Department of Physics x [µm]"— Presentation transcript:
Matter wave interferomery with poorly collimated beams x [µm] Ben McMorran, Alex Cronin Department of Physics x [µm]
main idea can get matter wave interference fringes with uncollimated beams but: grating position matters spatial coherence matters beam divergence matters grating alignment matters we’ve got a way to model this
outline 1. partial coherence in grating interferometers 2. examples of grating matter wave interferometers Mach-Zehnder atom interferometer Talbot-Lau C 60 interferometer Lau electron interferometer 3. grating alignment sensitivity 4. ideas for g measurement using uncollimated beam
… We simulate(1) the Talbot effect, (2) far-field diffraction, (3) Mach Zehnder interferometers (4) Talbot-Lau Interferometers (5) Lau interferometers … A Model for Partial Coherence and Wavefront Curvature in Grating Interferometers PRA (June 2008)
Atom Interferometer Objective: Pioneer new techniques using matter-wave interference to make precision measurements. Study quantum decoherence, Matter-wave index of refraction, Atomic polarizability. Approach: 3 nano-fabricated diffraction gratings. Mach-Zhender interferometer for atom-waves.. Interferometer Performance: Up to 50% contrast. Small phase drift (< 2 rad / hr). Layout is easily changed for new experiments. Macroscopic (100 m) path separation.
conclusion simulations + experiments: matter wave fringes can be formed with uncollimated beams necessary to think about partial coherence less coherence parallel to slits contrast sensitive to grating misalignment position echo behind 2 gratings useful for measure g? we have a tool to model this