2014/05/31 by Wei-Cheng Lee, Wei‐Cheng Lee, Wan Kyu Park +5 · 1 citation
Materials Science · Physics and Astronomy · #Condensed matter physics #Density of states #Electron #Fermi level #Fermi liquid theory #Fermi surface #Gapless playback #Iron-based superconductors research #Physics #Physics of Superconductivity and Magnetism #Quantum mechanics #Quasiparticle #Rare-earth and actinide compounds #Spectroscopy #Superconductivity #cond-mat.mes-hall #cond-mat.str-el
paper · pdf · doi:10.1073/pnas.1422509112
published as PNAS 112, 651 (2015) · 8 pages, 3 figures, submitted to PNAS, some typos are fixed
arxiv created 2014/11/24 · openalex publication_date 2015/01/05 · arxiv updated 2015/01/28 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We developed a microscopic theory for the point-contact conductance between a metallic electrode and a strongly correlated material using the nonequilibrium Schwinger-Kadanoff-Baym-Keldysh formalism. We explicitly show that, in the classical limit, contact size shorter than the scattering length of the system, the microscopic model can be reduced to an effective model with transfer matrix elements that conserve in-plane momentum. We found that the conductance dI/dV is proportional to the effective density of states, that is, the integrated single-particle spectral function A(ω = eV) over the whole Brillouin zone. From this conclusion, we are able to establish the conditions under which a non-Fermi liquid metal exhibits a zero-bias peak in the conductance. This finding is discussed in the context of recent point-contact spectroscopy on the iron pnictides and chalcogenides, which has exhibited a zero-bias conductance peak.