Field-controlled electronic breathing modes and transport in nanoporous graphene

Abstract Nanoporous graphene (NPG) has been previously fabricated by on-surface-self assembly in the form of arrays of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mo>∼</mml:mo> </mml:mrow> <mml:mn>1</mml:mn> </mml:mrow> </mml:math> nm-wide graphene nanoribbons connected via molecular bridges in a two-dimensional crystal lattice (Moreno et al 2018 Science 360 199). It is predicted that NPG may, despite its molecular structure, work as electron waveguides that display e.g. Talbot wave interference. Here, we theoretically demonstrate how the electronic wave guidance may be controlled by using of electrical fields transverse to the ribbons; at low fields, point-injected currents display spatially periodic patterns along the ribbons, while high fields localize the injected current to single ribbons. This behavior constitutes an electronic version of optical breathing modes of Bloch oscillations, providing a simple mechanism for controlling the current patterns down to the molecular scale. The robustness of the self-repeating patterns under edge disorder demonstrates that the breathing modes of single-ribbon injections offer exciting opportunities for applications in nanoelectronics, molecular sensing, and quantum information processing.