Sub-Sharvin conductance and incoherent shot-noise in graphene disks at magnetic field
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arXiv
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| Auteurs principaux: | , , |
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| Format: | Preprint |
| Publié: |
2024
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| _version_ | 1866909229214859264 |
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| author | Rycerz, Adam Rycerz, Katarzyna Witkowski, Piotr |
| author_facet | Rycerz, Adam Rycerz, Katarzyna Witkowski, Piotr |
| contents | Highly-doped graphene samples show the conductance reduced and the shot-noise power enhanced compared to standard ballistic systems in two-dimensional electron gas. These features can be understood within a model assuming incoherent scattering of Dirac electrons between two interfaces separating the sample and the leads. Here we find, by adopting the above-mentioned model for the edge-free (Corbino) geometry and by means of the computer simulation of quantum transport, that another graphene-specific feature should be observable when the current flow through a doped disk is blocked by high magnetic field. In case the conductance drops to zero, the Fano factor approaches the value of $F\approx{}0.56$, with a very weak dependence on the disk radii ratio. The role of finite source-drain voltages and the system behavior upon tuning the electrostatic potential barrier from a rectangular to parabolic shape are also discussed. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2404_13141 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Sub-Sharvin conductance and incoherent shot-noise in graphene disks at magnetic field Rycerz, Adam Rycerz, Katarzyna Witkowski, Piotr Mesoscale and Nanoscale Physics Highly-doped graphene samples show the conductance reduced and the shot-noise power enhanced compared to standard ballistic systems in two-dimensional electron gas. These features can be understood within a model assuming incoherent scattering of Dirac electrons between two interfaces separating the sample and the leads. Here we find, by adopting the above-mentioned model for the edge-free (Corbino) geometry and by means of the computer simulation of quantum transport, that another graphene-specific feature should be observable when the current flow through a doped disk is blocked by high magnetic field. In case the conductance drops to zero, the Fano factor approaches the value of $F\approx{}0.56$, with a very weak dependence on the disk radii ratio. The role of finite source-drain voltages and the system behavior upon tuning the electrostatic potential barrier from a rectangular to parabolic shape are also discussed. |
| title | Sub-Sharvin conductance and incoherent shot-noise in graphene disks at magnetic field |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2404.13141 |