We report a finding of a pressure-induced quantum critical transition in K0.8Fe(x)Se2 (x = 1.7 and 1.78) superconductors through in situ high-pressure electrical transport and x-ray diffraction measurements in diamond anvil cells. Transitions from metallic Fermi liquid behavior to non-Fermi liquid behavior and from antiferromagnetism to paramagnetism are found in the pressure range of 9.2-10.3 GPa, in which superconductivity tends to disappear. The change around the quantum critical point from the coexisting antiferromagnetism state and the Fermi liquid behavior to the paramagnetism state and the non-Fermi liquid behavior in the iron-selenide superconductors demonstrates a unique mechanism for their quantum critical transition.

Resistance measurements of a "111" type superconductor Li x FeAs ͑x = 0.8, 1.0, 1.1͒ were performed at high pressure. The superconductivity transition temperature ͑T c ͒ is found to decrease almost linearly with increasing pressure and the pressure derivative, dT c / dP, becomes smaller with increasing Li content. Electron spin resonance experiment at ambient pressure on a stoichometric sample shows gradual decrease in the spin moment and the loss of coherence of spin coupling as the temperature is lowered. A very weak Fe local moment is observed when the temperature is lowered to T c. In situ synchrotron radiation powder x-ray diffraction at high pressure shows changes in the resistivity are not related to a structural transition.

Recently, research has begun to investigate the reasons for differences in homeownership rates between Asian and whites. This paper extends this research by examining the heterogeneity that exists across Asian groups in the United States. We find that there are important differences across geographic area, across time, and across groups in the importance of various factors that influence the likelihood of owning a home. After controlling for household mobility and other socioeconomic characteristics, we find most Asian groups have homeownership rates similar to whites, but Chinese households have homeownership rates 20 percentage points higher than their household characteristics would predict. Part of this may be due to differences in support unmeasured in the data, but future research is needed to better understand the source of this differential.