Hamburg 2001 – scientific programme

Parts | Days | Selection | Search | Downloads | Help

TT: Tiefe Temperaturen

TT 6: Postersitzung I: Josephsonkontakte und SQUIDs, Supraleitung: Theorie, Korrelierte Elektronen, Niederdimensionale Systeme, Magnetotransport, Quantenhalleffekt, Kohlenstoff-Nanoröhrchen, Quantenflüssigkeiten

TT 6.52: Poster

Monday, March 26, 2001, 14:30–17:00, Rang S\ 3

Quantum Interference of Electrons in Fibrous Ta₄Te₄Si — •A. Stolovits¹, A. Sherman¹, K. Ahn², and R. K. Kremer² — ¹Tartu Ülikooli, Füüsika Instituut, Riia 142, EE-51014 Tartu, Estonia — ²MPI Für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germnay

The crystal structure of the quasi one-dimensional compound Ta₄Te₄Si contains Si centered square antiprismatic Ta₄Te₄ infinite chains which are weakly coupled to neighboring chains via Te-Te van der Waals interaction. According to band-structure calculations the structure should be stable and metallic with two half-filled and a twofold degenerate nearly half-filled conduction band. However, early resistivity measurements showed resistivity characteristics pointing to an electronic and structural instability in Ta₄Te₄Si as well.
Here we present a magnetoresistance study of crystalline Ta₄Te₄Si fibers (typical thickness < 5 µ m). Both, the temperature dependence of the resistivity and the magnetoresistance prove metallic behavior down to 1.7 K. The low-field magnetoresistance is interpreted in terms of three-dimensional anisotropic weak-localization theory. Carrier phase scattering lengths extracted from the magnetoresistance data are in good agreement with theoretical predictions for electron-electron interactions in disordered metals. Resistivity anomalies previously ascribed to charge density wave like anomalies are most likely due to crystalline imperfections induced by electrical current pulses.