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DS: Fachverband Dünne Schichten
DS 45: Poster IV: One-Dimensional Metals: Reality or Fiction
DS 45.22: Poster
Thursday, April 3, 2014, 16:00–19:00, P1
Experimental and theoretical evidence for a Peierls insulating state in the low-temperature phase of In/Si(111) — •Eric Jeckelmann1, Wolf Gero Schmidt2, Simone Sanna2, Norbert Esser3, and Eugen Speiser3 — 1Leibniz Universität Hannover — 2Universität Paderborn — 3ISAS, Berlin
We reinvestigate the phase transition in indium atomic wires on a Si(111) substrate experimentally with Raman spectroscopy and theoretically using first-principles simulations and model calculations. We construct an effective one-dimensional model for the electronic properties of In wires including a coupling to shear and rotary lattice deformations. Thereby the input parameters for the model calculations are obtained from first-principles frozen-phonon and deformation-potential calculations based on density-functional theory within the local density approximation (DFT-LDA). The present investigation demonstrates that both shear and rotary modes in the low-temperature phase can be interpreted as Peierls lattice deformations which are significantly softened as the temperature increases. This agrees remarkably well with the measured temperature dependence of the surface phonon frequencies in the In/Si(111) atomic wire structure.