21,377 research outputs found
Anomalous Parallel Field Negative Magnetoresistance in Ultrathin Films Near the Superconductor-Insulator Transition
A parallel field negative magnetoresistance has been found in
quench-condensed ultrathin films of amorphous bismuth in the immediate vicinity
of the thickness-tuned superconductor-insulator transition. The effect appears
to be a signature of quantum fluctuations of the order parameter associated
with the quantum critical point.Comment: Revised content includes revised argument and new figures 3 and 4.
Totals: 4 pages, 4 figure
Electrostatic Tuning of the Superconductor-Insulator Transition in Two Dimensions
Superconductivity has been induced in insulating ultra-thin films of
amorphous bismuth using the electric field effect. The screening of
electron-electron interaction was found to increase with electron concentration
in a manner correlated with the tendency towards superconductivity. This does
not preclude an increase in the density of states being important in the
development of superconductivity. The superconductor-insulator transition
appears to belong to the universality class of the three dimensional XY model.Comment: Four pages, three figures. Revised slightly to reflect referees'
comment
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