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H H Wen

Publications and source records attributed to H H Wen.

4 recordsLinked to original sources
PubMed2006

Large anisotropic normal-state magnetoresistance in clean MgB2 thin films.

We report a large normal-state magnetoresistance with temperature-dependent anisotropy in very clean epitaxial MgB2 thin films (residual resistivity much smaller than 1 microOmega cm) grown by hybrid physical-chemical vapor deposition. The magnetoresistance shows a complex dependence on the orientation of the applied magnetic field, with a large magnetoresistance (Delta(rho)/(rho)0=136%) observed for the field H perpendicular ab plane. The angular dependence changes dramatically as the temperature is increased, and at high temperatures the magnetoresistance maximum changes to H||ab. We attribute the large magnetoresistance and the evolution of its angular dependence with temperature to the multiple bands with different Fermi surface topology in MgB2 and the relative scattering rates of the sigma and pi bands, which vary with temperature due to stronger electron-phonon coupling for the sigma bands.

Journal Article↗
PubMed2000

Macroscopic phase separation in high-temperature superconductors.

High-temperature superconductivity is recovered by introducing extra holes to the Cu-O planes, which initially are insulating with antiferromagnetism. In this paper I present data to show the macroscopic electronic phase separation that is caused by either mobile doping or electronic instability in the overdoped region. My results clearly demonstrate that the electronic inhomogeneity is probably a general feature of high-temperature superconductors.

Journal Article↗
PubMedDate not supplied

Late metabolic acidosis in low-birth-weight babies: report of four cases.

Four low-birth-weight babies, though fed an adequate amount of formula, failed to regain their birth weight within ten days. Blood gas studies revealed metabolic acidosis in all. Their body weight gain improved dramatically after adding sodium bicarbonate to the milk. Late metabolic acidosis was presented, even using special premature formula, in three of them.

Acidosis↗