Volume 116, Number 5, December 2016
|Number of page(s)||7|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||20 January 2017|
Exciton condensation in an extended Falicov-Kimball model in the presence of orbital magnetic fields
1 Department of Physics, Indian Institute of Technology Kharagpur - Kharagpur-721302, India
2 Department of Physics, Jhargram Raj College - Jhargram-721507, India
3 Center for Theoretical Studies, Indian Institute of Technology Kharagpur - Kharagpur-721302, India
Received: 9 May 2016
Accepted: 28 December 2016
We investigate the exciton condensation in the presence of an external, perpendicular magnetic field in a two-dimensional extended spinless Falicov-Kimball model involving itinerant and localized electrons in the half-filled limit, using self-consistent, mean-field approximations. On tuning the orbital magnetic field the excitonic averages are affected in several ways: the external field usually suppresses the excitonic average but we find that it is also possible to enhance excitonic response at some values of the magnetic field. We further examine the effect of Coulomb interaction and the f-electron hopping on the condensation of excitons for some rational values of the applied magnetic fields. The interband Coulomb interaction enhances Δ exponentially and the effect is more pronounced for low hybridization. The strength of excitonic average drops when f-electrons have a dispersion. This trend is independent of the relative sign of the c- and f-electron hopping; although the excitonic response is different for different parity of the c- and f-electrons.
PACS: 71.35.-y – Excitons and related phenomena / 77.80.-e – Ferroelectricity and antiferroelectricity / 71.45.Lr – Charge-density-wave systems
© EPLA, 2016
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.