Google Play icon

New class of materials could power memory devices

Posted July 25, 2014

A new phase of matter known as topological insulators, until recently known only for esoteric quantum-mechanical properties, might have a practical use in controlling magnetic memory and logic devices.

A team of Cornell and Penn State University physicists has demonstrated for the first time that electrical currents flowing along the surface of topological insulators can exert a torque on an adjacent magnetic layer that is 10 times more efficient than any other known mechanism. This breakthrough provides a new strategy for making next-generation memory technologies that use the least possible energy and current.

The research, led by Dan Ralph, the F.R. Newman Professor of Physics at Cornell, and Nitin Samarth of Penn State, is published online July 24 in the journal Nature. The team used the topological insulator bismuth selenide (a combination of bismuth and selenium) for their experiments.

Like conventional insulators, topological insulators do not allow current to flow through the material, but they are different because they are wrapped in a conducting surface. Electrons flowing on the surface also do something unique: The direction of an electron’s spin is always locked perpendicular to its direction of motion. This locking provides a means for the flow of an electrical current along the surface to produce a buildup of spin that can apply torque to an adjacent magnet.

Ralph and colleagues are trying to develop new magnetic nonvolatile memory and logic devices. One of the main challenges in doing so is to find a way to quickly flip the devices’ magnetization using the least possible current.

The new results show that electrical current flowing within a thin film of bismuth selenide – at room temperature no less – can be used for this purpose.

The researchers caution that actual memory devices are a long way off, but the paper, Ralph noted, can be viewed as an exciting first step for a new branch of science.

Source: Cornell University

Featured news from related categories:

Technology Org App
Google Play icon
85,350 science & technology articles

Most Popular Articles

  1. New treatment may reverse celiac disease (October 22, 2019)
  2. "Helical Engine" Proposed by NASA Engineer could Reach 99% the Speed of Light. But could it, really? (October 17, 2019)
  3. New Class of Painkillers Offers all the Benefits of Opioids, Minus the Side Effects and Addictiveness (October 16, 2019)
  4. The World's Energy Storage Powerhouse (November 1, 2019)
  5. Plastic waste may be headed for the microwave (October 18, 2019)

Follow us

Facebook   Twitter   Pinterest   Tumblr   RSS   Newsletter via Email