Quantum Hall Effect and Chern Phases in the 1/5-Depleted Square Lattice
Fuente:
arXiv
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866916819863863296 |
|---|---|
| author | Aghtouman, Sara Gumbs, Godfrey Hosseini, Mir Vahid |
| author_facet | Aghtouman, Sara Gumbs, Godfrey Hosseini, Mir Vahid |
| contents | We investigate the fractional energy spectrum and quantum Hall response of a two-dimensional 1/5-depleted square lattice subjected to a perpendicular magnetic field. Using a tight-binding model that includes both nearest-neighbor (t_1) and next-nearest-neighbor (t_2) hopping, we compute the Hofstadter butterfly and extract quantized Hall conductivities via Chern number calculations. In the absence of diagonal hopping (t_2 =0), the spectrum exhibits exact particle-hole and flux-inversion symmetries, and the total Chern number across all bands vanishes. When t_2 is introduced, these symmetries are broken, the butterfly becomes deformed, new gaps open, and -remarkably-a nonzero total Chern sum can emerge, signaling unconventional topological phases. By systematically varying t_1 and t_2, we identify regimes with large individual Chern indices and parameter windows where gap stability and Hall plateaus are optimized. Our results demonstrated that lattice depletion combined with diagonal hopping provides a tunable route to engineer robust Chern insulators in both artificial and oxide-based square-lattice systems. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2507_00932 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Quantum Hall Effect and Chern Phases in the 1/5-Depleted Square Lattice Aghtouman, Sara Gumbs, Godfrey Hosseini, Mir Vahid Materials Science Mesoscale and Nanoscale Physics We investigate the fractional energy spectrum and quantum Hall response of a two-dimensional 1/5-depleted square lattice subjected to a perpendicular magnetic field. Using a tight-binding model that includes both nearest-neighbor (t_1) and next-nearest-neighbor (t_2) hopping, we compute the Hofstadter butterfly and extract quantized Hall conductivities via Chern number calculations. In the absence of diagonal hopping (t_2 =0), the spectrum exhibits exact particle-hole and flux-inversion symmetries, and the total Chern number across all bands vanishes. When t_2 is introduced, these symmetries are broken, the butterfly becomes deformed, new gaps open, and -remarkably-a nonzero total Chern sum can emerge, signaling unconventional topological phases. By systematically varying t_1 and t_2, we identify regimes with large individual Chern indices and parameter windows where gap stability and Hall plateaus are optimized. Our results demonstrated that lattice depletion combined with diagonal hopping provides a tunable route to engineer robust Chern insulators in both artificial and oxide-based square-lattice systems. |
| title | Quantum Hall Effect and Chern Phases in the 1/5-Depleted Square Lattice |
| topic | Materials Science Mesoscale and Nanoscale Physics |
| url | https://arxiv.org/abs/2507.00932 |