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ACP SCIENTIST TURCHANIN PUBLISHES IN NATURE NANOTECHNOLOGY


As part of an international consortium, together with colleagues from the University of Vienna, the Institut de Ciènces Fotòniques (Castelldefels), Tel Aviv University and Stanford University, ACP principal scientist Andrey Turchanin published on original research article titled "An atomically thin matter-wave beamsplitter" in Nature Nanotechnology (Nature Nanotechnol., advance online publication, doi:10.1038/nnano.2015.179) - congratulations!

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.

Turchnanin_Nature_Nanotech_Setup_web700

A nanomechanical implementation of the Bohr-Einstein debate. In our diffraction set-up (left) the suspended double slit of Bohr's Gedanken
experiment (right) is replaced by an ultrathin grating in graphene. In analogy to the Bohr-Einstein debate we ask whether the atomically thin
structure can encode information about the particle's path through the grating or whether it is compatible with high-contrast molecule interference.
Figure from Brand et al., Nature Nanotechnol., doi: 10.1038/nnano.2015.179.

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