The new circuit design offers a path to "spintronic" devices that use little electricity and practically generate no heat.
Spintronic devices leverage the "spin wave" -- a quantum property of electrons -- in magnetic materials. Until now, modulating spin waves has required injected electrical currents using bulky components that can cause signal noise and effectively negate any inherent performance gains.
"People are beginning to look for computing beyond silicon. Wave computing is a promising alternative," said Luqiao Liu, a professor in the Department of Electrical Engineering and Computer Science (EECS).
"By using this narrow domain wall, we can modulate the spin wave and create these two separate states, without any real energy costs. We just rely on spin waves and intrinsic magnetic material," explained Liu, also principal investigator of the Spintronic Material and Device Group in the Research Laboratory of Electronics.
The MIT researchers developed a circuit architecture that uses only a nanometer-wide domain wall in layered nanofilms of magnetic material to modulate a passing spin wave, without any extra components or electrical current.
In the future, pairs of spin waves could be fed into the circuit through dual channels, modulated for different properties, and combined to generate some measurable quantum interference -- similar to how photon wave interference is used for quantum computing.
Researchers hypothesize that such interference-based spintronic devices, like quantum computers, could execute highly complex tasks that conventional computers struggle with.
The researchers now hope to build a working wave circuit that can execute basic computations.