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HD Drew

Publications and source records attributed to HD Drew.

At least 19 recordsLinked to original sources
PubMed2000

Anomalous proximity effect in underdoped YBa2Cu3O6+x josephson junctions

Josephson junctions were photogenerated in underdoped thin films of the YBa2Cu3O6+x family using a near-field scanning optical microscope. The observation of the Josephson effect for separations as large as 100 nm between two wires indicates the existence of an anomalously large proximity effect and shows that the underdoped insulating material in the gap of the junction is readily perturbed into the superconducting state. The critical current of the junctions was found to be consistent with the conventional Josephson relationship. This result appears to constrain the applicability of SO(5) theory to explain the phase diagram of high critical temperature superconductors.

Journal Article↗
PubMed2000

Infrared hall effect in high- T(c) superconductors: evidence for non-fermi-liquid hall scattering

Infrared ( 20-120 and 900-1100 cm(-1)) Faraday rotation and circular dichroism are measured in high- T(c) superconductors using sensitive polarization modulation techniques. Optimally doped YBa2Cu3O7 thin films are studied at temperatures in the range ( 15<T<300 K) and magnetic fields up to 8 T. At 1000 cm(-1) the Hall conductivity sigma(xy) varies strongly with temperature in contrast to the longitudinal conductivity sigma(xx) which is nearly independent of temperature. The Hall scattering rate gamma(H) has a T2 temperature dependence but, unlike a Fermi liquid, depends only weakly on frequency. The experiment puts severe constraints on theories of transport in the normal state of high- T(c) superconductors.

Journal Article↗