Grüneisen ratio at the kondo-breakdown quantum critical point.
We show that the scenario of a multiscale Kondo-breakdown quantum critical point gives rise to a divergent Grüneisen ratio with an anomalous exponent 0.7. In particular, we fit the experimental data of YbRh2(Si0.95Ge0.05)2 for a specific heat, thermal expansion, and Grüneisen ratio based on our simple analytic expressions. A reasonable agreement between the experiment and theory is found for the temperature range between 0.4 and 10 K. We discuss how the Grüneisen ratio is a key measurement to discriminate between the Kondo-breakdown and spin-density wave theories.
Kim
K-S
KS
Institut de Physique Théorique, CEA, IPhT, CNRS, URA 2306, F-91191 Gif-sur-Yvette, France.
Benlagra
A
A
Pépin
C
C