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arXiv · 0909.1983

Separation of energy scales in undoped YbRh$_2$Si$_2$ under hydrostatic pressure

Yoshi Tokiwa·Philipp Gegenwart·Christoph Geibel·Frank Steglich
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Abstract

The temperature ($T$)-magnetic field ($H$) phase diagram of YbRh$_2$Si$_2$ in the vicinity of its quantum critical point is investigated by low-$T$ magnetization measurements. Our analysis reveals that the energy scale $T^\star(H)$, previously related to the Kondo breakdown and terminating at 0.06 T for $T\to 0$, remains unchanged under pressure, whereas the antiferromagnetic critical field increases from 0.06 T ($p=0$) to 0.29 T ($p=1.28$ GPa), resulting in a crossing of $T_N(H)$ and $T^\star(H)$. Our results are very similar to those on Yb(Rh$_{1-x}$Co$_x$)$_2$Si$_2$, proving that the Co-induced disorder can not be the reason for the detachment of both scales under chemical pressure.

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Yoshi Tokiwa, Philipp Gegenwart, Christoph Geibel, Frank Steglich. 2013-06-22. Separation of energy scales in undoped YbRh$_2$Si$_2$ under hydrostatic pressure. https://doi.org/10.1143/jpsj.78.123708

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