title: An atomically thin matter-wave beamsplitter.
abstract: Matter-wave interferometry has become an essential tool in studies on the foundations of quantum physics and for precision measurements. Mechanical gratings have played an important role as coherent beamsplitters for atoms, molecules and clusters, because the basic diffraction mechanism is the same for all particles. However, polarizable objects may experience van der Waals shifts when they pass the grating walls, and the undesired dephasing may prevent interferometry with massive objects. Here, we explore how to minimize this perturbation by reducing the thickness of the diffraction mask to its ultimate physical limit, that is, the thickness of a single atom. We have fabricated diffraction masks in single-layer and bilayer graphene as well as in a 1 nm thin carbonaceous biphenyl membrane. We identify conditions to transform an array of single-layer graphene nanoribbons into a grating of carbon nanoscrolls. We show that all these ultrathin nanomasks can be used for high-contrast quantum diffraction of massive molecules. They can be seen as a nanomechanical answer to the question debated by Bohr and Einstein of whether a softly suspended double slit would destroy quantum interference. In agreement with Bohr's reasoning we show that quantum coherence prevails, even in the limit of atomically thin gratings.
authors: Faculty of Physics, University of Vienna, VCQ, QuNaBioS, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors: Christian
authors: C
authors: Brand
authors: Faculty of Physics, University of Vienna, VCQ, QuNaBioS, Boltzmanngasse 5, A-1090 Vienna, Austria.|ICFO - Institut de Ciènces Fotòniques, 08860 Castelldefels (Barcelona), Spain.
authors: Michele
authors: M
authors: Sclafani
authors: Faculty of Physics, University of Vienna, VCQ, QuNaBioS, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors: Christian
authors: C
authors: Knobloch
authors: The Center for Nanosciences and Nanotechnology at Tel Aviv University.
authors: Yigal
authors: Y
authors: Lilach
authors: Faculty of Physics, University of Vienna, VCQ, QuNaBioS, Boltzmanngasse 5, A-1090 Vienna, Austria.|Physics Department, Stanford University, 382 Via Pueblo Mall, Stanford, California 94305-4060, USA.
authors: Thomas
authors: T
authors: Juffmann
authors: Faculty of Physics, University of Vienna, PNM, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors: Jani
authors: http://orcid.org/0000-0002-1301-5266
authors: J
authors: Kotakoski
authors: Faculty of Physics, University of Vienna, PNM, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors: Clemens
authors: C
authors: Mangler
authors: Friedrich Schiller University Jena, Institute of Physical Chemistry, Lessingstrasse 10, D-07743 Jena, Germany.
authors: Andreas
authors: A
authors: Winter
authors: Friedrich Schiller University Jena, Institute of Physical Chemistry, Lessingstrasse 10, D-07743 Jena, Germany.
authors: Andrey
authors: A
authors: Turchanin
authors: Faculty of Physics, University of Vienna, PNM, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors: Jannik
authors: J
authors: Meyer
authors: The Center for Nanosciences and Nanotechnology at Tel Aviv University.|Tel Aviv University, School of Chemistry, The Raymond and Beverly Faculty of Exact Sciences, Tel Aviv 69978, Israel.
authors: Ori
authors: O
authors: Cheshnovsky
authors: Faculty of Physics, University of Vienna, VCQ, QuNaBioS, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors: Markus
authors: M
authors: Arndt