Large positive correlation between the effective electron mass and the multipolar fluctuation in the heavy-fermion metal Ce${}_{1-x}$La${}_x$B${}_6$

Abstract

For the last few decades, researchers have been intrigued by multipolar ordering phenomena while looking for the related quantum criticality in the heavy-fermion Kondo system Ce${}_{1-x}$La${}_x$B${}_6$. However, critical phenomena induced by substitution level ($x$), temperature ($T$), and magnetic field ($B$) are poorly understood despite a large collection of experimental results is available. In this work, we present $T$-$B$, $x$-$T$, and $x$-$B$ phase diagrams of Ce${}_{1-x}$La${}_x$B${}_6$ ($\mathbf{B}\parallel [110]$). These are completed by analyzing heat capacity, magnetocaloric effect (MCE), and elastic neutron scattering. A drastic increase of the Sommerfeld coefficient ${\gamma }_0$, which is estimated from the heat capacity down to 0.05 K, is observed with increasing $x$. The precise $T$-$B$ phase diagram which includes an unforeseen high-entropy region is drawn by analyzing the MCE for the first time in Ce${}_{1-x}$La${}_x$B${}_6$. The $x$-$B$ phase diagram, which supports the existence of a QCP at $x>0.75$, is obtained by the same analysis. A detailed interpretation of phase diagrams strongly indicates positive correlation between the fluctuating multipoles and the effective electron mass.

11 pages, 8 figures

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Cited by in corpus (9)

• Possible quadrupole density wave in the superconducting Kondo lattice CeRh2As2
• Crystalline electric field of Ce in trigonal symmetry: CeIr3Ge7 as a model case
• Fermi Surface Nesting with Heavy Quasiparticles in the Locally Noncentrosymmetric Superconductor CeRh${}_2$As${}_2$
• Probing octupolar hidden order via Janus impurities
• Derivation of RKKY Interaction between Multipole Moments in CeB${}_6$ by the Effective Wannier Model based on the Bandstructure Calculation
• Doping-induced redistribution of magnetic spectral weight in substituted hexaborides Ce${}_{1-x}$La${}_x$B${}_6$ and Ce${}_{1-x}$Nd${}_x$B${}_6$
• Origin of the non-Fermi-liquid behavior in CeRh2As2
• Cascade of magnetic-field-driven quantum phase transitions in Ce3Pd20Si6
• Local origin of the strong field-space anisotropy in the magnetic phase diagrams of Ce${}_{1-x}$La${}_x$B${}_6$ measured in a rotating magnetic field