An atomically thin matter-wave beamsplitter
Author(s): C. Brand, M. Sclafani, C. Knobloch, Y. Lilach, T. Juffmann, J. Kotakoski, C. Mangler, A. Winter, A. Turchanin, J. C. Meyer, O. Cheshnovsky, M. Arndt
Journal: Nature Nanotechnology
DOI Number: 10.1038/nnano.2015.179
Link: Link to publication
Matter-wave interferometry has become an essential tool in studies on the foundations of quantum physics1 and for precision measurements2, 3, 4, 5, 6. Mechanical gratings have played an important role as coherent beamsplitters for atoms7, molecules and clusters8, 9, 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 walls10, 11, and the undesired dephasing may prevent interferometry with massive objects12. 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 Einstein13 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.