CeCu$_{2}$Ge$_{2}$: Challenging our understanding of quantum criticality

Here, we unveil evidence for a quantum phase transition in CeCu$_{2}$Ge$_{2}$. For the H//c-axis, no experimental evidence for QC. But as H is rotated towards the a-axis, these $\mu $'s increase considerably becoming undetectable for $\theta $ \textgreater 56$^{\circ}$. Around H$\sim $ 30 T the resistivity becomes $\propto $T which, coupled to the divergence of $\mu $, indicates the existence of a field-induced QC point(T $=$ 0 K). This observation, suggesting FS hot spots associated with the SDW nesting vector, is at odds with current QC scenarios for which the continuous suppression of all relevant energy scales at H$_{\mathrm{p}}(\theta $,T ) should lead to a line of quantum-critical points in the H-$\theta $ plane. Finally, we show that the complexity of its magnetic phase diagram(s) makes CeCu$_{2}$Ge$_{2}$ an ideal system to explore field-induced quantum tricritical and QC end points.