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MA: Magnetismus
MA 24: Hauptvortr
äge Brückl / Bangert
MA 24.1: Invited Talk
Thursday, March 27, 2003, 14:00–14:30, HSZ/04
New developments with Spin-dependent tunnel junctions — •Hubert Brückl — Universität Bielefeld, Fakultät für Physik, Universitätsstrasse 25, 33615 Bielefeld
Besides sensors, MRAM and magnetic hard disk heads, much more possible applications are still ahead for the new magnetoelectronic effects of Spin-dependent tunneling (SDT) junctions. In this contribution, we will discuss open questions in the physical understanding of SDT and give examples for new developments, e.g. towards application in logics or biochips.
Despite of the clear intention of the industry to introduce the projected devices the next year(s), basic mechanism of SDT are still unclear, like the contribution of scattering at defects, magnons and phonons to the tunnel current or the magnetic switching behavior of elements in the size range of 100 nm.
Besides new applications in logic devices, SDT junctions are promising sensors for magnetoresistive biochips, which are capable to detect even single molecules by functionalized magnetic particles. These magnetic particles are used as labels of biomolecules like DNA and can be detected by magnetoresistive sensors based on giant magnetoresistance or SDT. We present the principle and design of magnetoresistive biochips and compare the performance with the established fluorescent method.