Quantum Criticality in Kondo Compound CeAgBi2

We report a systematic study of the dense Kondo compound CeAgBi$_{2}$ by means of electrical resistivity, heat capacity, and magnetic measurements, including torque magnetometry and Sagnac interferometry. By comparing our results with previous reports, we observe at zero field a slightly larger antiferromagnetic ordering temperature at $T_{N} = 6.4$ K. Moreover, five field-induced metamagnetic transitions are observed in magnetic fields up to $12$ T applied parallel to the $c$-axis, including a remarkable signature for a first order transition at $H_{c}\sim 8$ T. The low temperature specific heat coefficient $\gamma$ and the $T^{2}$ resistivity coefficient also show a divergence at the same $H$, indicating a putative quantum critical point. This work is supported by NSF grant DMR-1350122. The development of Sagnac interferometer is supported by NSF grant ECCS-1346603.