• 文献标题:   Transport in a three-terminal graphene quantum dot in the multi-level regime
  • 文献类型:   Article
  • 作  者:   JACOBSEN A, SIMONET P, ENSSLIN K, IHN T
  • 作者关键词:  
  • 出版物名称:   NEW JOURNAL OF PHYSICS
  • ISSN:   1367-2630
  • 通讯作者地址:   Swiss Fed Inst Technol
  • 被引频次:   12
  • DOI:   10.1088/1367-2630/14/2/023052
  • 出版年:   2012

▎ 摘  要

We investigate transport in a three-terminal graphene quantum dot. All nine elements of the conductance matrix have been independently measured. In the Coulomb blockade regime, accurate measurements of individual conductance resonances reveal slightly different resonance energies depending on which pair of leads is used for probing. Rapid changes in the tunneling coupling between the leads and the dot due to localized states in the constrictions have been excluded by tuning the difference in resonance energies using in-plane gates which couple preferentially to individual constrictions. The interpretation of the different resonance energies is then based on the presence of a number of levels in the dot with an energy spacing of the order of the measurement temperature. In this multi-level transport regime, the three-terminal device offers the opportunity to sense if the individual levels couple with different strengths to the different leads. This in turn gives qualitative insight into the spatial profile of the corresponding quantum dot wave functions.