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University of Pittsburgh researchers have shown that novel oxide-based magnetism follows electrical commands, which could be a path towards spin-based computing.

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Towards spin-based computing
It’s a given that semiconductors process electrical information, while magnetic materials enable long-term data storage. Along these lines, researchers from the University of Pittsburgh and the University of Wisconsin-Madison have discovered a way to fuse these two distinct properties in a single material that they believe could pave the way for new ultrahigh density storage and computing architectures.

While phones and laptops rely on electricity to process and temporarily store information, long-term data storage is still largely achieved via magnetism. Discs coated with magnetic material are locally oriented (e.g. North or South to represent “1” and “0”), and each independent magnet can be used to store a single bit of information. However, this information is not directly coupled to the semiconductors used to process information. Having a magnetic material that can store and process information would enable new forms of hybrid storage and processing capabilities.

Magnetic states at oxide interfaces controlled by electricity. Top image show magnetic state with -3 volts applied, and bottom image shows nonmagnetic state with 0 volts applied. (Source: University of Pittsburgh)

Magnetic states at oxide interfaces controlled by electricity. Top image show magnetic state with -3 volts applied, and bottom image shows nonmagnetic state with 0 volts applied.
(Source: University of Pittsburgh)

The material created is capable of a form of magnetism that can be stabilized with electric fields rather than magnetic fields. Working with a material formed from a thick layer of one oxide—strontium titanate—and a thin layer of a second material—lanthanum aluminate—the researchers have found that the interface between the materials can exhibit magnetic behavior that is stable at room temperature. The interface is normally conducting, but by “chasing” away the electrons with an applied voltage (equivalent to that of two AA batteries), the material becomes insulating and magnetic. The magnetic properties are detected using “magnetic force microscopy,” an imaging technique that scans a tiny magnet over the material to gauge the relative attraction or repulsion from the magnetic layer.