Magnetologic with alpha-MnAs thin films.

Taking advantage of the spin information in present day computing is expected to yield an enormous increase in efficiency. A promising ferromagnetic material compatible with semiconductors for room temperature applications is MnAs. By sensitive cantilever beam magnetometry, we discovered that alpha-MnAs films on GaAs(001) exhibit an additional small out-of-plane component of the magnetization which is magnetically coupled with the dominant in-plane magnetization.

Ferromagnetism of MnAs studied by heteroepitaxial films on GaAs(001).

Thin epitaxial films of MnAs--promising candidates for the spin injection into semiconductors--are well known to undergo simultaneously a first-order structural and magnetic phase transition at 10-40 degrees C. The evolution of stress and magnetization of MnAs/GaAs(001), both measured quantitatively with our cantilever beam magnetometer at the coexistence region of alpha-MnAs and beta-MnAs, reveal an orthorhombically distorted unit cell of the ferromagnetic phase, which provides important clues on the origin of ferromagnetism in MnAs.

Programmable computing with a single magnetoresistive element.

The development of transistor-based integrated circuits for modern computing is a story of great success. However, the proved concept for enhancing computational power by continuous miniaturization is approaching its fundamental limits. Alternative approaches consider logic elements that are reconfigurable at run-time to overcome the rigid architecture of the present hardware systems.

One-dimensional spin-polarized quantum-wire states in Au on Ni(110).

Au chain structures have been prepared on Ni(110). Au6 s,p-derived features in photoemission spectra are identified as quantum-wire states due to their strong dispersion along the chains and absence of dispersion perpendicular to the chains in agreement with our ab initio calculation of the electronic structure. Spin analysis reveals that the states have minority-spin character showing that the confinement of electrons in the chain structure depends on the electron spin.