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Magnetic-Field Induced Quantum Critical Point in YbRh$_2$Si$_2$

P. Gegenwart·J. Custers·C. Geibel·K. Neumaier·T. Tayama·K. Tenya·O. Trovarelli·F. Steglich
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Abstract

We report low-temperature calorimetric, magnetic and resistivity measurements on the antiferromagnetic (AF) heavy-fermion metal YbRh$_2$Si$_2$ (${T_N =}$ 70 mK) as a function of magnetic field $B$. While for fields exceeding the critical value ${B_{c0}}$ at which ${T_N\to0}$ the low temperature resistivity shows an ${AT^2}$ dependence, a ${1/(B-B_{c0})}$ divergence of ${A(B)}$ upon reducing $B$ to ${B_{c0}}$ suggests singular scattering at the whole Fermi surface and a divergence of the heavy quasiparticle mass. The observations are interpreted in terms of a new type of quantum critical point separating a weakly AF ordered from a weakly polarized heavy Landau-Fermi liquid state.

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P. Gegenwart, J. Custers, C. Geibel, K. Neumaier, T. Tayama, K. Tenya, O. Trovarelli, F. Steglich. 2002-06-15. Magnetic-Field Induced Quantum Critical Point in YbRh$_2$Si$_2$. https://doi.org/10.1103/physrevlett.89.056402

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