2005/04/14 by Satoshi Ejima, Florian Gebhard, Satoshi Nishimoto · 5 citations
Materials Science · Physics and Astronomy · #Electronic and Structural Properties of Oxides #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.str-el
paper · pdf · doi:10.1209/epl/i2005-10020-8
published as Europhys. Lett., 70, 492 (2005) · 7 pages, 4 figures
openalex publication_date 2005/04/14 · arxiv created 2005/07/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
The Tomonaga-Luttinger parameter K ρ determines the critical behavior in quasi–one-dimensional correlated electron systems, e.g. , the exponent α for the density of states near the Fermi energy. We use the numerical density-matrix renormalization group method to calculate K ρ from the slope of the density-density correlation function in momentum space at zero wave vector. We check the accuracy of our new approach against exact results for the Hubbard and XXZ Heisenberg models. We determine K ρ in the phase diagram of the extended Hubbard model at quarter filling, n c = 1/2, and confirm the bosonization results K ρ = n c 2 = 1/4 on the critical line and K ρ CDW = n c 2 /2 = 1/8 at infinitesimal doping of the charge-density-wave (CDW) insulator for all interaction strengths. The doped CDW insulator exhibits exponents α > 1 only for small doping and strong correlations.