The Vienna Doctoral Programme on Complex Quantum Systems
invites to a
Students TALK
by
Lukas Mairhofer
Coherent deflectometry in a matter-wave interferometer for
biomolecules
Matter-wave interference has been demonstrated for molecules with up to 10.000 amu
(Eibenberger, PCCP 15, 2013). The amplitude and phase of the fringe pattern are sensitive to
external forces of 10e-24 N. If a deflecting field maintains the spatial coherence of the
molecule´s center-of-mass wave-function, the interferometer thus can enhance the resolution of
deflection measurements by four orders of magnitude compared to classic ballistic
deflectometry. Such experiments were conducted with static electric fields (Eibenberger, NJP 13,
2011). Also the absorption of a single photon suffices to shift the interference pattern
(Eibenberger, PRL 112, 2014).
Thus matter-wave interferometry enhanced deflectometry makes precision measurements on
complex biomolecules feasible. We will introduce a source for beams of internally cold, neutral
and intact biomolecules up to 3000 amu that are sufficiently slow and intense for matter-wave
interference. We will present a magnet array suitable for spatially coherent deflection of
diamagnetic molecules. The determination of the molecules´ magnetic, electric and optical
properties allows conclusions about their structure. Thus we can investigate photo-induced
conformational changes in molecules like beta-Carotene and Retinal and even photochemistry in
the gas phase in molecules like Resveratrol or Dehydrocholestorol. Furthermore magnetic
deflectometry will allow us to study the role of electron-delocalization and spin-coupling as
coherence mechanisms in aromatic bonds.