Atomic collapse in gapped graphene: lattice and valley effects
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arXiv
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| Autori principali: | , , , , , |
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| Natura: | Preprint |
| Pubblicazione: |
2025
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| _version_ | 1866913666501181440 |
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| author | Wang, Jing Wu, Xiaotai Zhao, Wen-Sheng Cheng, Yuhua Hu, Yue Peeters, Francois M. |
| author_facet | Wang, Jing Wu, Xiaotai Zhao, Wen-Sheng Cheng, Yuhua Hu, Yue Peeters, Francois M. |
| contents | We study the atomic collapse phenomenon in $K$ and $K'$ valley of gapped graphene. Bound states induced by Coulomb impurity in the gap turn into atomic collapse resonances as the charge increases beyond the supercritical charge $Z_c$. $Z_c$ increases sublinear with the band gap $Δ$. The atomic collapse resonances result in peaks in the LDOS at the same energies in $K$ and $K'$ valley, but the strong (weak) LDOS peaks in $K$ valley are weak (strong) LDOS peaks in $K'$ valley reminiscent of pseudospin polarization phenomenon. From a spatial LDOS analysis of the atomic collapse resonance states, we assign specific atomic orbitals to the atomic collapse resonances. Remarkably, the two $p$ atomic orbital atomic collapse states are no longer degenerate and splits into two having lobes in different directions in the graphene plane. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2501_15049 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Atomic collapse in gapped graphene: lattice and valley effects Wang, Jing Wu, Xiaotai Zhao, Wen-Sheng Cheng, Yuhua Hu, Yue Peeters, Francois M. Mesoscale and Nanoscale Physics We study the atomic collapse phenomenon in $K$ and $K'$ valley of gapped graphene. Bound states induced by Coulomb impurity in the gap turn into atomic collapse resonances as the charge increases beyond the supercritical charge $Z_c$. $Z_c$ increases sublinear with the band gap $Δ$. The atomic collapse resonances result in peaks in the LDOS at the same energies in $K$ and $K'$ valley, but the strong (weak) LDOS peaks in $K$ valley are weak (strong) LDOS peaks in $K'$ valley reminiscent of pseudospin polarization phenomenon. From a spatial LDOS analysis of the atomic collapse resonance states, we assign specific atomic orbitals to the atomic collapse resonances. Remarkably, the two $p$ atomic orbital atomic collapse states are no longer degenerate and splits into two having lobes in different directions in the graphene plane. |
| title | Atomic collapse in gapped graphene: lattice and valley effects |
| topic | Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2501.15049 |