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arXiv · 2202.09642

Anisotropy of Kondo-lattice coherence in momentum space for CeCoIn5

Mai Ye·Hsiang-Hsi Kung·Priscila F. S. Rosa·Eric D. Bauer·Kristjan Haule·Girsh Blumberg
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Abstract

We study the electronic and phononic excitations of heavy-fermion metal CeCoIn$_5$ by polarization-resolved Raman spectroscopy to explore the Kondo-lattice coherence. Below the coherence temperature T*\,=\,45\,K, the continuum of electronic excitations in the XY scattering geometry is suppressed at frequencies below 50\,cm$^{-1}$, whereas the low-frequency continuum in the X'Y' geometry exhibits no change across T*. We relate the suppression to the reduced electron-electron scattering rate resulting from the coherence effect. The presence of suppression in the XY geometry and absence of it in the X'Y' geometry implies that the $\alpha$ and $\beta$ bands become coherent below T*, whereas the $\gamma$ band remains largely incoherent down to 10\,K. Moreover, two optical phonon modes exhibit anomalies in their temperature dependence of the frequency and linewidth below T*, which results from developing coherent spectral weight near the Fermi level and reduced electron-phonon scattering rate. Our results further support the key role of anisotropic hybridization in CeCoIn$_5$.

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Mai Ye, Hsiang-Hsi Kung, Priscila F. S. Rosa, Eric D. Bauer, Kristjan Haule, Girsh Blumberg. 2022-02-19. Anisotropy of Kondo-lattice coherence in momentum space for CeCoIn5. https://arxiv.org/abs/2202.09642

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