New magnetic field dependence of Landau levels in a graphenelike structure |
| |
Authors: | Dietl Petra Piéchon Frédéric Montambaux Gilles |
| |
Affiliation: | Laboratoire de Physique des Solides, Université Paris Sud, CNRS UMR8502, Orsay Cedex, France. |
| |
Abstract: | We consider a tight-binding model on the honeycomb lattice in a magnetic field. For special values of the hopping integrals, the dispersion relation is linear in one direction and quadratic in the other. We find that, in this case, the energy of the Landau levels varies with the field B as epsilon(n)(B) ~ [(n+gamma)B](2/3). This result is obtained from the low-field study of the tight-binding spectrum on the honeycomb lattice in a magnetic field (Hofstadter spectrum) as well as from a calculation in the continuum approximation at low field. The latter links the new spectrum to the one of a modified quartic oscillator. The obtained value gamma=1/2 is found to result from the cancellation of a Berry phase. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|