• 文献标题:   Mechanically controlled quantum interference in graphene break junctions
  • 文献类型:   Article
  • 作  者:   CANEVA S, GEHRING P, GARCIASUAREZ VM, GARCIAFUENTE A, STEFANI D, OLAVARRIACONTRERAS IJ, FERRER J, DEKKER C, VAN DER ZANT HSJ
  • 作者关键词:  
  • 出版物名称:   NATURE NANOTECHNOLOGY
  • ISSN:   1748-3387 EI 1748-3395
  • 通讯作者地址:   Delft Univ Technol
  • 被引频次:   10
  • DOI:   10.1038/s41565-018-0258-0
  • 出版年:   2018

▎ 摘  要

The ability to detect and distinguish quantum interference signatures is important for both fundamental research and for the realization of devices such as electron resonators(1), interferometers(2) and interference-based spin filters(3). Consistent with the principles of subwavelength optics, the wave nature of electrons can give rise to various types of interference effects(4), such as Fabry-Perot resonances(5), Fano resonances(6) and the Aharonov-Bohm effect(7). Quantum interference conductance oscillations(8) have, indeed, been predicted for multiwall carbon nanotube shuttles and telescopes, and arise from atomic-scale displacements between the inner and outer tubes(9,10). Previous theoretical work on graphene bilayers indicates that these systems may display similar interference features as a function of the relative position of the two sheets(11,12). Experimental verification is, however, still lacking. Graphene nanoconstrictions represent an ideal model system to study quantum transport phenomena(13-15) due to the electronic coherence(16) and the transverse confinement of the carriers(17). Here, we demonstrate the fabrication of bowtie-shaped nano-constrictions with mechanically controlled break junctions made from a single layer of graphene. Their electrical conductance displays pronounced oscillations at room temperature, with amplitudes that modulate over an order of magnitude as a function of subnanometre displacements. Surprisingly, the oscillations exhibit a period larger than the graphene lattice constant. Charge-transport calculations show that the periodicity originates from a combination of the quantum interference and lattice commensuration effects of two graphene layers that slide across each other. Our results provide direct experimental observation of a Fabry-Perot-like interference of electron waves that are partially reflected and/or transmitted at the edges of the graphene bilayer overlap region.