Understanding Why Electrons Move the Way They Do
If you pour a bucket of water down an incline, you would expect any material engulfed by the water to flow down the incline with it. When dealing with an electric current and electrons though, the reverse can happen, and researchers have been unable to explain why for years. Now those at MIT have found an answer that is not what some would expect.
To study the phenomenon the researchers placed a thin film of a ferromagnetic material between a platinum base and a layer of an oxide material. When a current was put through the composite material, the magnetic domains of the electron in the ferromagnetic material were found to move against the current. The researchers then repeated the test exactly, except that the metal tantalum replaced platinum and now the domains moved with the current. This suggests the asymmetric flow of the domains is not dependent on the ferromagnetic material they are in, but on the metal next to it. Such behavior is called a chiral effect, meaning it is dependent on direction, and this is the first time it has ever been demonstrated with magnetic domains.
The researchers have also found that the force on the magnetic domains to flip, which is necessary for the writing of data, can be multiplied by a factor of 10,000. Such an effect could be used to enhance magnetic data storage devices to the point of out-competing other, modern memory systems.