NER: Molecule Diffraction and Interferometry Using NanoStructures

University Of Arizona, Tucson AZ

Investigators

Abstract

Controlling the quantum coherence of strongly interacting particles is one of the grand challenges in quantum engineering. In this context, polar molecules and electrons are strongly interacting compared to atoms and neutrons, because of their electric dipole moment and electric charge. Coherent diffraction of these particles from nano-scale structures will allow us to measure any perturbations to their quantum state directly by observing the phase and contrast in their de Broglie wave interference fringes. Furthermore, diffraction and interference of polar molecules represents research at the interface between nanotechnology, condensed matter physics, and atomic physics. Improved gratings with a 100-nanometer period have enabled several atomic physics and atom-surface studies. The purpose of this NER proposal is to further develop nanostructure grating technology to study polar molecules, clusters of atoms, and also electrons. This research is exploratory because charged particles or even molecules with large dipole moments are prone to decoherence. Interactions with the environment, such as scattering molecules from a background gas, or de-phasing due to stray electric fields, will reduce the contrast of interference patterns. Even interactions with the nanostructure gratings themselves may limit the phase coherence of molecule waves. This research will prove the feasibility of matter wave interferometry with polar molecules and electrons using nanotechnology gratings. Once proven, several experiments are possible with molecule and electron interferometers. One application of a molecular interferometer is the measurement of van der Waals interactions between isolated molecules and surfaces a few nanometers away. Another application is to measure the tensor components of polarizability for molecules and clusters. Inertial sensing with molecules and holography with low energy electrons will also be studied. Broader Impact Molecular interferometers are good candidates for ultra precise accelerometers and gyroscopes. Because of their short wavelengths, molecular interferometers will provide sensitivity to rotation rates smaller than 1E-9 radians per second given one second of integration time. Gyroscopes with this sensitivity will be of interest to geophysics as well as fundamental physics studies. Electron diffraction from nanofabricated gratings could revolutionize electron holography. Because the nanostructures work as transmission optics with actual slots on the nanoscale, these gratings will enable electron holography with two orders of magnitude smaller electron energy than presently is possible. Education will be a major result of this proposed work. Currently three graduate students, and four undergraduates work on atom optics with the PI. Two students have the Optical Sciences Center as their home department, so we are building strong ties between the Physics Department and Optical Sciences Center at the University of Arizona. Our laboratory gives approximately 30 tours a year to groups of high school students, engineers, undergraduate classes, graduate students and visitors. The P.I. also teaches physics classes each semester and gives talks on quantum optics and new developments in matter wave interferometry. This outreach is combined with web publications and journal articles to communicate results.