Dresden 2009 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 38: Correlated Electrons: Low-dimensional Systems - Models 1

TT 38.8: Vortrag

Donnerstag, 26. März 2009, 11:30–11:45, HSZ 301

Correlation and impurities in carbon nanotubes: A DMRG approach — •Alexander Struck¹, Sebastian A. Reyes^1,2, and Sebastian Eggert¹ — ¹Department of Physics and Reserch Center OPTIMAS, Univ. Kaiserslautern, Kaiserslautern, Germany — ²Departamento de Física Pontificia Universidad Católica de Chile, Santiago de Chile, Chile

Carbon nanotubes (CNTs) are well suited to study strong electronic correlations in quasi-one-dimensional systems experimentally and theoretically. Of particular interest is the interplay of interactions between the conducting electrons and impurities in the nanotube. Impurities include the boundaries of short tubes as well as structural imperfections such as the Stone-Wales lattice distortion. Interactions can lead to different phases of the electron liquid, depending on their range and strength, and can produce quasi-localized ground states of e.g. the Mott insulator type or a charge density wave. In this talk, we introduce effective lattice models to describe armchair and zigzag nanotubes with different types of impurities at low energies. The models are quasi-one dimensional and allow straightforward use in 1D techniques like the density-matrix renormalization group (DMRG). We discuss impurity effects in armchair CNTs and the influence of electron-electron interaction using DMRG calculations.