Correlated Electronic States Under Extreme Conditions

Strongly correlated matter can exhibit novel behavior ranging from superfluidity to exotic magnetism. When condensed-matter systems are subjected to cryogenic temperatures, strong correlations are often revealed; however, the physical properties arising from these correlations can yield surprising, yet poorly understood, results. How then can we explore the new emergent phenomena arising from strong correlations? The application of high pressures and high magnetic fields can perturb these materials in a systematic fashion, providing insight into the fundamental mechanisms at work. Four strongly correlated materials are subjected to high pressures or high magnetic fields at very low temperatures to explore the coexistence of superconductivity and non-Fermi liquid behavior near antiferromagnetic quantum critical points; the evolution and competition of superconductivity, 'hidden order', and antiferromagnetism; and the effects of pressure on superconductivity in an f-electron actinide element. The results of these experimental studies reveal a glimpse of the underlying phenomena and substantiate the use of pressure and magnetic field to probe strong electronic correlations.