Violation of the Time-Reversal and Particle-Hole Symmetries in Strongly Correlated Fermi Systems: A Review

V R Shaginyan,G S Japaridze,V A Stephanovich,A Z Msezane

doi:10.3390/sym12101596

Abstract

In this review, we consider the time reversal T and particle-antiparticle C symmetries that, being most fundamental, can be violated at microscopic level by a weak interaction. The notable example here is from condensed matter, where strongly correlated Fermi systems like heavy-fermion metals and high Tc superconductors exhibit C and T symmetries violation due to so-called non-Fermi liquid (NFL) behavior. In these systems, tunneling differential conductivity (or resistivity) is a very sensitive tool to experimentally test the above symmetry break. When a strongly correlated Fermi system turns out to be near the topological fermion condensation quantum phase transition (FCQPT), it exhibits the NFL properties, so that the C symmetry breaks down, making the differential tunneling conductivity to be an asymmetric function of the bias voltage V. This asymmetry does not take place in normal metals, where Landau Fermi liquid (LFL) theory holds. Under the application of magnetic field, a heavy fermion metal transits to the LFL state, and σ(V) becomes symmetric function of V. These findings are in good agreement with experimental observations. We suggest that the same topological FCQPT underlies the baryon asymmetry in the Universe. We demonstrate that the most fundamental features of the nature are defined by its topological and symmetry properties.

Highlights

IntroductionSymmetry 2020, 12, 1596 σasym (V ) ≡ I 0 (V ) − I 0 (−V ) (I 0 ≡ dI/dV, where I is a tunneling current and V is a bias voltage) can be observed when a system with strongly correlated heavy fermions (like electrons and/or holes) is both in its normal and superconducting state [3,4,5,6,7,8,9]
Unusual properties of strongly correlated Fermi systems are observed in superconductors with high Tc (HTSC) and in heavy fermion (HF) metals due to a quantum phase transition (QPT) occurring at its quantum critical point (QCP) at T = 0
Knowledge of such symmetries and conditions for their violation permit us to gain a general knowledge about physical systems without solving any equations, which are often very complicated

Summary

Introduction

Symmetry 2020, 12, 1596 σasym (V ) ≡ I 0 (V ) − I 0 (−V ) (I 0 ≡ dI/dV, where I is a tunneling current and V is a bias voltage) can be observed when a system with strongly correlated heavy fermions (like electrons and/or holes) is both in its normal and superconducting state [3,4,5,6,7,8,9] We note that such an asymmetry does not occur in conventional metals, especially at low temperatures.

Quantum Phase Transitions

Fermion Condensation State

Asymmetric Conductivity Near the Topological FCQPT

Asymmetric Conductivity in Heavy-Fermion Metals and High Tc Superconductors

Violation of T and C Symmetries in the Universe

Conclusions