Inclined junction in monolayer graphene: A gateway toward tailoring valley polarization of Dirac fermions

Fuente: arXiv
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Main Authors: Tapar, Shrushti, Muralidharan, Bhaskaran
Format: Preprint
Published: 2024
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author Tapar, Shrushti
Muralidharan, Bhaskaran
author_facet Tapar, Shrushti
Muralidharan, Bhaskaran
contents Generating discernible valley contrasts and segregating valley-indexed fermions in real space within graphene poses considerable challenges due to the isotropic transport within the continuum energy range for degenerate valleys. This study unveils an interesting finding: introducing valley contrast through anisotropic chiral transport in isotropic Dirac systems like graphene, achieved by implementing a tilted PN junction. The tilted junction shifts the angular spectrum to larger angles in accordance with the tilt angle. This modifies the pseudospin-conserved modes across the junction, resulting in valley-resolved chiral transport. This approach not only induces valley splitting within the real space but also preserves the remarkable mobility of fermions, offering distinct advantages over alternative strategies. The comprehensive analysis includes optimizing the experimental setup, scrutinizing factors such as the sequence of the doped region, and examining critical parameters like the tilt angle delta and transition width d across the junction. Surprisingly, an increased transition width enhances transmission, attributed to specular edge scattering. Importantly, the system remains resilient to Anderson short-range edge disorder. The broader implication lies in the transformative potential of inducing analogous anisotropic chiral transport behaviors in isotropic Dirac systems, resembling the characteristics of tilted Dirac-Weyl semimetals, by incorporating a tilted PNJ.
format Preprint
id arxiv_https___arxiv_org_abs_2402_14210
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Inclined junction in monolayer graphene: A gateway toward tailoring valley polarization of Dirac fermions
Tapar, Shrushti
Muralidharan, Bhaskaran
Mesoscale and Nanoscale Physics
Generating discernible valley contrasts and segregating valley-indexed fermions in real space within graphene poses considerable challenges due to the isotropic transport within the continuum energy range for degenerate valleys. This study unveils an interesting finding: introducing valley contrast through anisotropic chiral transport in isotropic Dirac systems like graphene, achieved by implementing a tilted PN junction. The tilted junction shifts the angular spectrum to larger angles in accordance with the tilt angle. This modifies the pseudospin-conserved modes across the junction, resulting in valley-resolved chiral transport. This approach not only induces valley splitting within the real space but also preserves the remarkable mobility of fermions, offering distinct advantages over alternative strategies. The comprehensive analysis includes optimizing the experimental setup, scrutinizing factors such as the sequence of the doped region, and examining critical parameters like the tilt angle delta and transition width d across the junction. Surprisingly, an increased transition width enhances transmission, attributed to specular edge scattering. Importantly, the system remains resilient to Anderson short-range edge disorder. The broader implication lies in the transformative potential of inducing analogous anisotropic chiral transport behaviors in isotropic Dirac systems, resembling the characteristics of tilted Dirac-Weyl semimetals, by incorporating a tilted PNJ.
title Inclined junction in monolayer graphene: A gateway toward tailoring valley polarization of Dirac fermions
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2402.14210