Magnetotransport properties governed by antiferromagnetic fluctuations in the heavy-fermion superconductor ${\text{CeIrIn}}_5$

In quasi-two-dimensional $\text{Ce}\left(\text{Ir},\text{Rh}\right){\text{In}}_5$ system, it has been suggested that the phase diagram contains two distinct domes with different heavy-fermion superconducting states. Here, we report the systematic pressure dependence of the electron transport properties in the normal state of ${\text{CeRh}}_{0.2}{\text{Ir}}_{0.8}{\text{In}}_5$ and ${\text{CeIrIn}}_5$, which locates in first and second superconducting domes, respectively. We observed non-Fermi liquid behavior at low temperatures in both compounds, including nonquadratic $T$ dependence of the resistivity, large enhancement of the Hall coefficient, and the violation of the Kohler rule in the magnetoresistance. We show that the cotangent of the Hall angle $\text{cot}{\Theta }_H$ varies as $T^2$, and the magnetoresistance is quite scaled well by the Hall angle as $\Delta {\rho }_{xx}/{\rho }_{xx}\propto {\text{tan}}^2{\Theta }_H$. The observed transport anomalies are common features of $\text{Ce}M{\text{In}}_5$ ($M=\text{Co}$, Rh, and Ir) and high-$T_c$ cuprates, which suggest that the anomalous transport properties observed in ${\text{CeIrIn}}_5$ are mainly governed by the antiferromagnetic spin fluctuations not by the Ce-valence fluctuations, which have been proposed to be the possible origin for the second superconducting dome.

Figure 1

Schematic $T\text{−}x$ phase diagram for ${\text{CeRh}}_{1-x}{\text{Ir}}_x{\text{In}}_5$ and $T\text{−}P$ phase diagram for ${\text{CeIrIn}}_5$ (Refs. 9, 10, 11).

Figure 2

(a) Temperature dependence of resistivity for ${\text{CeIrIn}}_5$ at 0, 0.56, 0.98, 1.59, and 2.41 GPa. (b) Temperature dependence of resistivity for ${\text{CeRh}}_{0.2}{\text{Ir}}_{0.8}{\text{In}}_5$ at 0, 0.49, 1.11, 1.50, and 2.19 GPa. The insets are expanded views at low temperatures. Down arrows drawn in main panels indicate $T_{\text{coh}}$ at ambient pressure, where the resistivity shows a broad maximum. Open circles shown in the insets indicate the resistivity at $T_m$, where $R_H$ shows a minimum. For detail, see the text in Sec. 4.

Figure 3

Field dependence of ${\rho }_{xy}$ for ${\text{CeIrIn}}_5$ at ambient pressure.

Figure 4

(a) Temperature dependence of $R_H$ for ${\text{CeIrIn}}_5$ at several pressures [0 $(●)$, 0.56 $(■)$, 0.98 $(▲)$, 1.56 $(◆)$, and 2.41 GPa $(▼)$] and for ${\text{LaIrIn}}_5$ at ambient pressure $(○)$. $R_H$ is defined by the zero-field limit for derivative of ${\rho }_{xy}$. Inset: temperature dependence of $R_H$ for ${\text{CeIrIn}}_5$ at 0 $(●)$, 1 $(+)$, and 5 T $(\times )$ at ambient pressure. (b) Temperature dependence of $R_H$ for ${\text{CeRh}}_{0.2}{\text{Ir}}_{0.8}{\text{In}}_5$ at several pressures [0 $(●)$, 0.49 $(■)$, 1.11 $(▲)$, 1.50 $(◆)$, and 2.19 GPa $(▼)$] and for ${\text{LaIrIn}}_5$ at ambient pressure $(○)$. Inset: temperature dependence of $R_H$ for ${\text{CeRh}}_{0.2}{\text{Ir}}_{0.8}{\text{In}}_5$ at 0 $(●)$, 1 $(+)$, and 5 T $(\times )$ at ambient pressure. Down and up arrows in main panels indicate $T_{\text{coh}}$ at ambient pressure determined by the resistivity peak and $T_m$ at ambient pressure, where $R_H$ shows a minimum, respectively.

Figure 5

$\left|\text{cot}{\Theta }_H\right|$ as a function of ${\left(T/T_{\text{coh}}\right)}^2$ for ${\text{CeIrIn}}_5$ at 0 $(●)$, 0.56 $(○)$, 0.98 $(■)$, 1.59 $(\square )$, and 2.41 GPa $(▲)$.

Figure 6

Magnetoresistance of ${\text{CeIrIn}}_5$ as a function of $H$ at (a) 0 GPa and (b) 2.41 GPa.

Figure 7

Kohler’s plot: $\Delta {\rho }_{xx}/{\rho }_{xx}\left(0\right)$ vs ${\mu }_{0}H/{\rho }_{xx}\left(0\right)$ for ${\text{CeIrIn}}_5$ at (a) 0 and (b) 2.41 GPa. Modified Kohler’s plot: $\Delta {\rho }_{xx}/{\rho }_{xx}\left(0\right)$ as a function of ${\text{tan}}^2{\Theta }_H$ for ${\text{CeIrIn}}_5$ at (c) 0 and (d) 2.41 GPa.