Twist-controlled resonant tunnelling in graphene/boron nitride/graphene heterostructures
Nature Publishing Group
Recent developments in the technology of van der Waals heterostructures made from two-dimensional atomic crystals have already led to the observation of new physical phenomena, such as the metal-insulator transition and Coulomb drag, and to the realization of functional devices, such as tunnel diodes, tunnel transistors and photovoltaic sensors. An unprecedented degree of control of the electronic properties is available not only by means of the selection of materials in the stack, but also through the additional fine-tuning achievable by adjusting the built-in strain and relative orientation of the component layers. Here we demonstrate how careful alignment of the crystallographic orientation of two graphene electrodes separated by a layer of hexagonal boron nitride in a transistor device can achieve resonant tunnelling with conservation of electron energy, momentum and, potentially, chirality. We show how the resonance peak and negative differential conductance in the device characteristics induce a tunable radiofrequency oscillatory current that has potential for future high-frequency technology.
This work was supported by the European Research Council, EC-FET European Graphene Flagship, Engineering and Physical Sciences Research Council (UK), the Leverhulme Trust (UK), the Royal Society, the US Office of Naval Research, US Air Force Office of Scientific Research, US Army Research Office and RS-RFBR, grant numbers 14-02-00792 and 13-02-92612 (Russian Federation). Y-J.K. was supported by the Global Research Lab Program (2011-0021972) through the National Research Foundation of Korea funded by the Ministry of Science, ICT & Future, Korea.
This is the author accepted manuscript. The final version is available from Nature Publishing Group via the DOI in this record.
Vol. 9, pp. 808 - 813
Place of publication