Ballistic transport across gate-controlled graphene superlattice

CHE-PIN HSU^1*, SZU-CHAO CHEN³, AITOR GARCIA-RUIZ¹, ALINA MRE ´NCA-KOLASI ´NSKA², DENIS KOCHAN¹, MING-HAO LIU¹

¹Department of Physics, National Cheng Kung University, Tainan, Taiwan
²Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Krak´ow, Poland
³Department of Electro-Optics Engineering, National Formosa University, Yunlin, Taiwan

* Presenter:CHE-PIN HSU, email:alex72329@gmail.com

Since the fabrication technique of gate-controlled graphene superlattice was developed in 2018 [1], research on graphene-based quantum systems has attracted much attention. By utilizing etched SiO₂ substrates, a periodic potential can be electrically controlled, significantly modifying electronic structure of graphene. This modification gives rise to a variety of large-scale graphene phenomena in quantum transport simulations [2, 3]. Despite these fruitful discoveries, quantum transport in normal-graphene/superlattice-graphene/normal-graphene (NGr/SGr/NGr) heterojunctions have not yet been investigated. Here, we present quantum transport simulations for two-terminal NGr/SGr/NGr heterojunctions with and without the applied magnetic field. At zero magnetic field, our conductance simulation reveals Fabry-P\'erot interference from the SGr cavity due to various satellite Dirac cones, which disperse with the magnetic field differently up to B ∼ 0.3 T, beyond which the fractal spectrum known as the Hofstadter’s butterfly emerges. Our work reveals novel transport phenomena in such NGr/SGr/NGr devices, highlighting the need for future experimental efforts to confirm our predictions

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Keywords: Quantum transport simulation, single layer graphene , gate-controlled superlattice, P\'erot interference, Hofstadter’s butterfly