OBSERVATION OF QUANTIZED VORTICES IN SUPERCONDUCTORS BY ELECTRON WAVES

Coherent field-emission electron beams and electron holography techniq ues have made it possible to produce interference micrographs from whi ch the phase distribution of the wave function of an electron beam tra nsmitted through an object relative to that of a reference beam can be measured to within 1/100th of the electron wavelength. This has opene d up a new way to make ultrafine measurements of material structures a nd of electromagnetic field distributions. Magnetic lines of force of quantized vortices in a superconducting thin film, for example, have b een directly observed by electron-holographic interference microscopy. In addition, the dynamics of individual vortices interacting with pin ning centers has been observed in real time by Lorentz microscopy. (C) 1998 Elsevier Science B.V. All rights reserved.