Quantum phase transition in CeCoIn₅: Experimental facts and theory

¹ Petersburg Nuclear Physics Institute of NRC “Kurchatov Institute” - Gatchina, 188300, Russia
² Clark Atlanta University - Atlanta, GA 30314, USA
³ NRC Kurchatov Institute - Moscow, 123182, Russia
⁴ Moscow Institute of Physics and Technology, Dolgoprudny - Moscow District 141700, Russia
⁵ National Research University Higher School of Economics - St. Petersburg, 194100, Russia

^(a) E-mail: vrshag@thd.pnpi.spb.ru (corresponding author)

Received: 15 January 2023
Accepted: 11 August 2023

Abstract

The condensed-matter community is involved in a hot debate on the nature of quantum critical points (QCP) governing the low-temperature properties of heavy fermion metals. The smeared jump-like behavior revealed both in the residual resistivity and the Hall resistivity R_H, along with the violation of the time invariance symmetry and the charge invariance , include the violation of quasiparticle-hole symmetry, and provide vital clues on the origin of both the non-Fermi-liquid behavior and QCP. For the first time, based on a number of important experimental data, we show that these experimental observations point out unambiguously that QCP of is accompanied by the symmetry violation, and QCP itself is represented by the topological fermion-condensation quantum phase transition (FCQPT) connecting two Fermi surfaces of different topological charges.