Non-Fermi-liquid behavior at anti-ferromagnetic quantum critical point in heavy fermion system Ce(Cu$_{1-x}$Co$_x$)$_2$Ge$_2$

Rajesh Tripathi; Debarchan Das; C. Geibel; S. K. Dhar; Z. Hossain

doi:10.1103/PhysRevB.98.165136

paper

Non-Fermi-liquid behavior at anti-ferromagnetic quantum critical point in heavy fermion system Ce(Cu $_{1 - x}$ Co $_{x}$ ) $_{2}$ Ge $_{2}$

arXiv:1808.05529 · doi:10.1103/PhysRevB.98.165136

Abstract

Polycrystalline samples of Ce(Cu $_{1 - x}$ Co $_{x}$ ) $_{2}$ Ge $_{2}$ were investigated by means of electrical resistivity $ρ$ ( $T$ ), magnetic susceptibility $χ$ ( $T$ ), specific heat $C$ $_{p}$ ( $T$ ) and thermo electric power $S$ ( $T$ ) measurements. The long-range antiferromagnetic (AFM) order, which set in at $T$ $_{N}$ = 4.1 K in CeCu $_{2}$ Ge $_{2}$ , is suppressed by non-iso-electronic cobalt (Co) doping at a critical value of the concentration $x$ $_{c}$ = 0.6, accompanied by non-Fermi liquid (NFL) behavior inferred from the power law dependence of heat capacity and susceptibility i.e. $C$ ( $T$ )/ $T$ and $χ$ ( $T$ ) $\propto$ $T$ $^{- 1 + λ}$ down to 0.4 K, along with a clear deviation from $T$ $^{2}$ behavior of the electrical resistivity. However, we have not seen any superconducting phase in the quantum critical regime down to 0.4 K.

8 pages, 11 figures

Non-Fermi-liquid behavior at anti-ferromagnetic quantum critical point in heavy fermion system Ce(Cu1−x​Cox​)2​Ge2​

Abstract

Non-Fermi-liquid behavior at anti-ferromagnetic quantum critical point in heavy fermion system Ce(Cu $_{1 - x}$ Co $_{x}$ ) $_{2}$ Ge $_{2}$