Biomedical subjects

D Grundler

Publications and source records attributed to D Grundler.

4 recordsLinked to original sources

PubMed2006

Spin-wave interference in microscopic rings.

We have studied the spin excitations of ferromagnetic rings and observed a distinct series of quantized modes in the vortex state. We attribute them to spin waves that circulate around the ring and interfere constructively. They form azimuthal eigenmodes of a magnetic ring resonator which we resolve up to the fourth order. The eigenfrequencies are calculated semianalytically and classified as a function of magnetic field by a quantization rule which takes into account a periodic boundary condition. Strikingly each mode exists only below a characteristic field.

Journal Article↗

PubMed2001

Oscillatory spin-filtering due to gate control of spin-dependent interface conductance.

Using the Landauer-Büttiker formalism, we study ballistic transport properties of an interface between a ferromagnetic metal and a mesoscopic two-dimensional electron system in a III-V semiconductor. We show that in a Sharvin point contact spin-filtering occurs due to band structure mismatch. Theory predicts a pronounced effect for Fe on InAs which can be controlled via a gate electrode.

Journal Article↗

PubMed2000

Large Rashba splitting in InAs quantum wells due to electron wave function penetration into the barrier layers.

We report on zero-field spin splitting of two-dimensional electron systems. Though absent in the unbiased InAs square asymmetric quantum well (SAQW), the Rashba splitting becomes pronounced by applying a positive back-gate voltage. In our SAQW, the Rashba parameter alpha increases with electron density and is tuned by a factor of about 2 using an additional front gate without charging the well. We argue that the band-edge profile provides the important contribution for spin-orbit interaction due to barrier penetration of the envelope wave function. This mechanism can provide the potential for high speed implementation in spintronics.

Journal Article↗

PubMed1986

[Cardiogenic embolisms following silent anterior wall infarct].

A 33-year-old man had suffered recurrent arterial embolisms. Echocardiography identified as the most likely cause a large mobile mass in the left ventricle. Initially a primary heart tumor was discussed, but the ECG finding of an anterolateral scar and an angiographically proven LAD-stenosis were suspicious of an organized thrombus of the left ventricle. After surgical excision, histological analysis classified the mass as an organized thrombus.

Adult↗