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Thursday March 11 at 2:00 pm (GMT+1) Paris time
Evidence for the coexistence between linearly dispersing bands and strong electronic correlations in the underlying kagome lattice of Na2/3CoO2
Electronic topology in metallic kagome compounds is under intense scrutiny. I’ll present transport experiments in the specific Na cobaltate phase Na2/3CoO2 in which the Na order differentiates a Co kagome sub-lattice in the triangular CoO2 layers.
Hall and magneto-resistance (MR) data under high fields give evidence for the coexistence of light and heavy carriers. At low temperatures, the dominant light carrier conductivity at zero field is suppressed by a B-linear MR suggesting Dirac like quasiparticles. Lifshitz transitions induced at large B and T unveil the lower mobility carriers. They display a negative B2 MR due to scattering from magnetic moments likely pertaining to a flat band. We underline an analogy with heavy Fermion physics.
