2004/05/31 by R. Mélin, K. Biljakovic, K. Biljakovi +2 · 1 citation
Materials Science · Physics and Astronomy · #Condensed matter physics #Density of states #Friedel oscillations #Impurity #Organic and Molecular Conductors Research #Physics #Power law #Quantum #Quantum and electron transport phenomena #Quantum mechanics #Relaxation (psychology) #Spectroscopy and Quantum Chemical Studies #Spin (aerodynamics) #Thermodynamics #cond-mat.dis-nn
paper · pdf · doi:10.1140/epjb/e2005-00082-x
published as Eur. Phys. J. B 43, 489-501 (2005) · 13 pages, 10 figures, improvements in the presentation
arxiv created 2004/12/21 · openalex publication_date 2005/02/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We investigate collective effects in the strong pinning model of disordered charge and spin density waves (CDWs and SDWs) in connection with heat relaxation experiments. We discuss the classical and quantum limits that contribute to two distinct contribution to the specific heat (a Cv ∼ T-2 contribution and a Cv ∼ Tα contribution respectively), with two different types of disorder (strong pinning versus substitutional impurities). From the calculation of the two level system energy splitting distribution in the classical limit we find no slow relaxation in the commensurate case and a broad spectrum of relaxation times in the incommensurate case. In the commensurate case quantum effects restore a non vanishing energy relaxation, and generate stronger disorder effects in incommensurate systems. For substitutional disorder we obtain Friedel oscillations of bound states close to the Fermi energy. With negligible interchain couplings this explains the power-law specific heat Cv ∼ Tα observed in experiments on CDWs and SDWs combined to the power-law susceptibility χ(T)∼ T-1+α observed in the CDW o-TaS3.