Stable and tunable charge carrier control of graphene for quantum resistance metrology

Here we demonstrate a stable and tunable method to alter the carrier concentration of epitaxial graphene grown on silicon carbide. This technique relies on chemical doping by an acceptor molecule. Through careful tuning one can produce chemically doped graphene quantum resistance devices which show long-term stability in ambient conditions and have performance comparable to that of GaAs quantum resistance standards. This development paves the way for controlled device fabrication of graphene quantum hall resistance standards, which can be reliably tailored to operate below 5 T and above 4 K out-of-the-box, without further adjustments from the end-user.
Funding Agencies|Swedish-Korean Basic Research Cooperative Program of the NRF [2014R1A2A1A12067266]; Swedish Foundation for Strategic Research (SSF) [IS14-0053]; Swedish Research Council (VR); VINNOVA; Knut and Alice Wallenberg Foundation; Chalmers Area of Advance NANO