Nernst effect of high-mobility Weyl electrons in NdAlSi enhanced by a Fermi surface nesting instability

Abstract

The thermoelectric Nernst effect of solids converts heat flow to beneficial electronic voltages. Here, using a correlated topological semimetal with high carrier mobility $\mu$ in presence of magnetic fluctuations, we demonstrate an enhancement of the Nernst effect close to a magnetic phase transition. A magnetic instability in NdAlSi modifies the carrier relaxation time on 'hotspots' in momentum space, causing a strong band filling dependence of $\mu$. We quantitatively derive electronic band parameters from a novel two-band analysis of the Nernst effect $S_{xy}$, in good agreement with quantum oscillation measurements and band calculations. While the Nernst response of NdAlSi behaves much like conventional semimetals at high temperatures, an additional contribution $\Delta S_{xy}$ from electronic correlations appears just above the magnetic transition. Our work demonstrates the engineering of the relaxation time, or the momentum-dependent self energy, to generate a large Nernst response independent of a material's carrier density, i.e. for metals, semimetals, and semiconductors with large $\mu$.

References in corpus (10)

• Heavy Fermions and Quantum Phase Transitions
• Visualizing pair formation on the atomic scale in the high-Tc superconductor Bi2Sr2CaCu2O8+d
• Quantum oscillations, thermoelectric coefficients and the Fermi surface of semi-metallic WTe2
• Large Seebeck Effect by Charge-Mobility Engineering
• Nernst effect in semi-metals: the meritorious heaviness of electrons
• Topological Kagome magnet Co3Sn2S2 thin flakes with high electron mobility and large anomalous Hall effect
• Decrease of upper critical field with underdoping in cuprate superconductors
• Critical enhancement of thermopower in a chemically tuned polar semimetal MoTe${}_2$
• Magnetotransport of multiple-band nearly-antiferromagnetic metals due to "hot-spot" scattering
• What is measured when measuring a thermoelectric coefficient?

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• Correlation between Complex Spin Textures and the Magnetocaloric and Hall Effects in Eu(Ga${}_{1-x}$Al${}_x$)${}_4$ ($x$ = 0.9, 1)
• Crystalline electric field excitations in Weyl semimetal \textit{R}AlSi (\textit{R} = Ce, Pr and Nd)
• Correlated helimagnetic configuration in a nonsymmorphic magnetic nodal semimetal
• Accessing quasi-flat $\text{f}$-bands to harvest large Berry curvature in NdGaSi
• Material realization of spinless, covalent-type Dirac semimetals in three dimensions