Dresden 2006 – scientific programme

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TT: Tiefe Temperaturen

TT 26: Transport - Poster Session

TT 26.7: Poster

Wednesday, March 29, 2006, 14:30–18:30, P1

Anomalies in Coupled Quantum Chains as resonances of the bands — •Luca Alloatti¹ and Giuseppe Grosso² — ¹Max-Planck Institut fuer Metallforschung, Heisenbergstr. 3, D-70569 Stuttgart, Germany — ²NEST-INFM and Dipartimento di Fisica No-dqE. FermiNo-dq, Universita’ di Pisa, Via F. Buonarroti 2, I-56127 Pisa, Italy

We consider the disordered quasi-one-dimensional single particle tight-binding hopping model and we show that the anomalies in the density of states, in the mean conductance and the even-odd effect are related to a resonance of the band structure of the perfect system underlying the disorder and not necessarily to the E=0 point. For the one-dimensional case we calculate the coefficients of the perturbation expansion of the mean conductance up to the twelfth order for both the pure diagonal and real off-diagonal disorder. This calculation evidences a profound difference between the two cases. In the case of two coupled chains we calculate the same expansion to the the fourth order and for general disorder. This is sufficient to make important predictions well verified numerically.