The Hall coefficient of quantum-critical Cr

Chromium is an itinerant antiferromagnet that exhibits a pressure-tuned continuous quantum phase transition [1]. The Hall coefficient is particularly sensitive to critical behavior in itinerant systems and magnetotransport measurements of single crystal Cr in a diamond anvil cell at low temperature reveal deviations from weak-coupling for P $\sim$ 10 GPa, We find a pseudogap-like regime of carrier deficiency for pressures just above the critical point. This behavior stands at odds with the behavior at the doping-driven quantum phase transition and helps elucidate the effects of quantum fluctuations without disorder. \\[4pt] [1] R. Jaramillo et al., Nature 459, 405 (2009).