Magnetic quantum critical point and dimensionality trend in cerium-based heavy-fermion compounds

We present realistic Kondo-lattice simulation results for the recently discovered heavy-fermion antiferromagnet ${\text{CePt}}_2{\text{In}}_7$ comparing with its three-dimensional counterpart ${\text{CeIn}}_3$ and the less two-dimensional ones, Ce-115’s. We find that the distance to the magnetic quantum critical point is the largest for ${\text{CeIn}}_3$ and the smallest for Ce-115’s, and ${\text{CePt}}_2{\text{In}}_7$ falls in between. We argue that the trend in quasi-two-dimensional materials stems from the frequency dependence of the hybridization between cerium $4f$ electrons and the conduction bands.

Figure 1

(Color online) Hybridization function calculated by LDA with Hubbard-I approximation for ${\text{CePt}}_2{\text{In}}_7$, Ce-115’s, and ${\text{CeIn}}_3$ using the code described in Ref. 16. The trace in the vertical axis quantity is taken over 14 orbitals of the $4f$ orbital of cerium.

Figure 2

(Color online) Temperature dependence of the inverse of the staggered susceptibility in the realistic Kondo-lattice models for ${\text{CePt}}_2{\text{In}}_7$ by which we identify that the phase boundary is located in $1.33J_{\text{K},0}<J_{\text{K}}<1.34J_{\text{K},0}$, where $J_{\text{K},0}$ is the Kondo coupling which corresponds to $U=5\left(\text{eV}\right)$ and $J_{\text{Hund}}=0$.

Figure 3

(Color online) Restored realistic Doniach phase diagram for ${\text{CePt}}_2{\text{In}}_7$ from the data in Fig. 2. AF is the antiferromagnetic phase and PM is the paramagnetic phase. The line is a guide to the eyes.

Figure 4

(Color online) Realistic Doniach phase diagram for ${\text{CePt}}_2{\text{In}}_7$, and Ce-115’s together with their parent compound, ${\text{CeIn}}_3$ with the horizontal axis rescaled to measure the distance to the magnetic QCP. The line is a guide to the eyes.

Figure 5

(Color online) Temperature dependence of the real part of the conduction-electron self-energy for ${\text{CePt}}_2{\text{In}}_7$, cerium-115’s, and ${\text{CeIn}}_3$.