Anomalous low temperature states in CeNi2Ge2and CePd2Si2

Abstract
High purity samples of the paramagnetic 4f-electron metal CeNi2Ge2 exhibit a non-Fermi-liquid form of the resistivity Δρ~Tx with xT as a function of magnetic field and pressure show that this strange metallic phase is connected to the proximity of an antiferromagnetic quantum critical point as in the isoelectronic relative CePd2Si2 near 2.8 GPa. The anomalous power-law dependence is surprisingly stable over extended ranges in temperature and pressure and challenges current theory of magnetic quantum phase transitions.