%D 2011 %N 4 %T Quantum critical metamagnetism of Sr3Ru2O7 under hydrostatic pressure %A W Wu %A A McCollam %A SA Grigera %A RS Perry %A AP Mackenzie %A SR Julian %V 83 %O This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. %X Using ac susceptibility, we have determined the pressure dependence of the metamagnetic critical endpoint temperature T ∗ for a field applied in the ab plane in the itinerant metamagnet Sr3Ru2O7. We find that T ∗ falls monotonically to zero as pressure increases, producing a quantum critical endpoint (QCEP) at Pc ∼ 13.6 ± 0.2 kbar. New features are observed near the QCEP—the slope of T ∗ versus pressure changes at ∼12.8 kbar, and weak subsidiary maxima appear on either side of the main susceptibility peak at pressures near Pc—indicating that some new physics comes into play near the QCEP. Clear signatures of a nematic phase, however, that were seen in field-angle tuning of T ∗ are not observed. As T ∗ is suppressed by pressure, the metamagnetic peak in the susceptibility remains sharp as a function of an applied magnetic field. As a function of temperature, however, the peak becomes broad with only a very weak maximum, suggesting that, near the QCEP, the uniform magnetization density is not the order parameter for the metamagnetic transition. %J Physical Review B %L discovery10134056 %I AMER PHYSICAL SOC