High Pressure Probes of Magnetic Quantum Phase Transitions

Magnetic susceptibility and electrical transport measurements in concert with diamond anvil cell techniques permit access to magnetic quantum critical points impossible to access by other means. We combine a continuously variable high-pressure cell with an optical system for in situ pressure calibration and Raman capability that can be cooled to pumped helium temperatures. With this system, we investigate the P-T phase diagram of the spin-density wave antiferromagnet chromium. We discuss its quantum critical behavior along with the possibility of alternative correlated phases as the magnetic order is suppressed in the zero-temperature limit.