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H E Hoenig

Publications and source records attributed to H E Hoenig.

3 recordsLinked to original sources
PubMed2001

Degenerate ground state in a mesoscopic YBa2Cu3O(7-x) grain boundary Josephson junction.

We have measured the current-phase relationship I(varphi) of symmetric 45 degrees YBa2Cu3O7-x grain boundary Josephson junctions. Substantial deviations of the Josephson current from conventional tunnel-junction behavior have been observed: (i) The critical current exhibits, as a function of temperature T, a local minimum at a temperature T*. (ii) At T approximately T*, the first harmonic of I(phi) changes sign. (iii) For T<T*, the second harmonic of I(phi) is comparable to the first harmonic, and (iv) the ground state of the junction becomes degenerate. The results are in good agreement with a microscopic model of Josephson junctions between d-wave superconductors.

Journal Article↗
PubMed1993

Experience with a multichannel system for biomagnetic study.

The components of the biomagnetic multichannel system Krenikon are described. The combination of biomagnetically yielded localizations with anatomic images gained from MR or CT is discussed as well as the enhancement of the signal-to-noise ratio by using a correlation technique. The overall localization accuracy is tested with technical phantoms. With volunteers measurements of auditory, visual and somatosensory evoked fields are performed to evaluate the system performance in vivo. Clinical studies were performed mainly with partners from the Universities of Erlangen-Nünberg and Ulm. The data acquisition time typically is 2-10 min which is tolerable both for the patient and the clinical staff. Electric potentials even with invasive electrodes can be recorded simultaneously with the magnetic fields. MEG gives important information for the presurgical diagnosis of epileptic patients and for the understanding of the epilepsy genesis. With MCG, centres of biologic excitation such as ventricular ectopies or accessory bundles in WPW syndrome have been successfully localized.

Biology↗