Back to Search
Start Over
Enhancing the stability of a fractional Chern insulator against competing phases
- Source :
- Phys. Rev. B 86, 205125 (2012)
- Publication Year :
- 2012
-
Abstract
- We construct a two-band lattice model whose bands can carry the Chern numbers C=0,pm1,pm2. By means of numerical exact diagonalization, we show that the most favorable situation that selects fractional Chern insulators (FCIs) is not necessarily the one that mimics Landau levels, namely a flat band with Chern number 1. First, we find that the gap, measured in units of the on-site electron-electron repulsion, can increase by almost two orders of magnitude when the bands are flat and carry a Chern number C=2 instead of C=1. Second, we show that giving a width to the bands can help to stabilize a FCI. Finally, we put forward a tool to characterize the real-space density profile of the ground state that is useful to distinguish FCI from other competing phases of matter supporting charge density waves or phase separation.<br />Comment: 10 pages, 6 figures
- Subjects :
- Condensed Matter - Strongly Correlated Electrons
Subjects
Details
- Database :
- arXiv
- Journal :
- Phys. Rev. B 86, 205125 (2012)
- Publication Type :
- Report
- Accession number :
- edsarx.1207.4097
- Document Type :
- Working Paper
- Full Text :
- https://doi.org/10.1103/PhysRevB.86.205125