Metamagnetism in CeIrIn5: magnetoresistance and dHvA study

Quantum phase transitions correspond to a continuous ground state transformation at T=0 driven by quantum fluctuations. A Fermi Surface change might be expected at a quantum critical point. The metamagnetic transition, corresponding to a non-linear increase in magnetization of a paramagnet, has been focus of attention since strong deviations from Fermi Liquid theory reported in Sr$_{3}$Ru$_{2}$O$_{7}$ have raised the possibility of a metamagnetic quantum critical end-point. CeIrIn$_{5}$, a heavy fermion compound with a recently discovered metamagnetic transition at high fields, offers yet another playground for such investigations. We report a study of magnetoresistance and de-Haas-van-Alphen effect (dHvA) in CeIrIn5 for magnetic fields up to 45T and in the temperature range 0.03K-1K. We found that the metamagnetic transition is marked by a concomitant drop in the resistivity and in the amplitude of dHvA oscillations as the magnetic field is increased, while the Fermi Surface remains intact. Possible scenarios will be discussed.