Number of the records: 1
Correlations in a band insulator
- 1.
SYSNO ASEP 0337277 Document Type J - Journal Article R&D Document Type Journal Article Subsidiary J Článek ve WOS Title Correlations in a band insulator Title Korelace v pásovém izolátoru Author(s) Sentef, M. (DE)
Kuneš, Jan (FZU-D) RID, ORCID, SAI
Werner, P. (CH)
Kampf, A. P. (DE)Number of authors 4 Source Title Physical Review. B - ISSN 1098-0121
Roč. 80, č. 15 (2009), 155116/1-155116/7Number of pages 7 s. Language eng - English Country US - United States Keywords electronic correlations ; dynamical mean-field theory ; band insulator Subject RIV BM - Solid Matter Physics ; Magnetism CEZ AV0Z10100521 - FZU-D (2005-2011) UT WOS 000271352000049 DOI 10.1103/PhysRevB.80.155116 Annotation We study a model of a covalent band insulator with on-site Coulomb repulsion at half filling using dynamical mean-field theory. Upon increasing the interaction strength the system undergoes a discontinuous transition from a correlated band insulator to a Mott insulator with hysteretic behavior at low temperatures. Increasing the temperature in the band insulator close to the insulator-insulator transition we find a crossover to a Mott insulator at elevated temperatures. Remarkably, correlations decrease the energy gap in the correlated band insulator. The gap renormalization can be traced to the low-frequency behavior of the self-energy, analogously to the quasiparticle renormalization in a Fermi liquid. While the uncorrelated band insulator is characterized by a single gap for both charge and spin excitations, the spin gap is smaller than the charge gap in the correlated system. Workplace Institute of Physics Contact Kristina Potocká, potocka@fzu.cz, Tel.: 220 318 579 Year of Publishing 2010
Number of the records: 1