Asymmetric Conductivity of Strongly Correlated Compounds

Abstract

In this chapter, we show that the FC solutions for distribution function $n_0(\mathbf{p})$ generate NFL behavior, and violate the particle-hole symmetry inherent in LFL. This, in turn, yields dramatic changes in transport properties of HF metals, particularly, the differential conductivity becomes asymmetric. As it is demonstrated in Sect. 3.1, Fermi quasiparticles can behave as Bose one. Such a state is viewed as possessing the supersymmetry (SUSY) that interchanges bosons and fermions eliminating the difference between them. In the case of asymmetrical conductivity it is the emerging SUSY that violates the time invariance symmetry. Thus, restoring one important symmetry, the FC state violates another essential symmetry. As is shown in Sect. 5.3, the LFL behavior is restored under the application of magnetic field. Therefore, we expect that in magnetic fields SUSY is violated and the asymmetric part of the differential conductivity is suppressed. Scanning tunneling microscopy and point-contact spectroscopy closely related to the Andreev reflection are sensitive to both the density of states and the probability of the population of quasiparticle states determined by the function $n(\mathbf{p},T)$ [1, 2]. Thus, the above experimental techniques are ideal tools for studying specific features of the NFL behavior of HF metals and high-$T_c$ superconductors.