New Zero-Power Carbon Interconnect Could Tap Electron Spin to Power Up Battery-Based Devices

In order to satisfy the Air Force’s requirements to create tech devices that need the least charging in the field, researchers at the University of Texas at San Antonio (UTSA) are employing principles in quantum science and engineering to develop a graphene-based logic device.

This innovative technology will optimize the energy efficiency of battery-based devices ranging from computers to cell phones.

“We are developing devices that can operate almost battery-less,” stated Ethan Ahn, UTSA assistant professor in electrical engineering.

Engineers at UTSA are employing spintronics, the study of the spin of an electron, which is an inherent quantum mechanical property, to enable low-power operation with a probable application in quantum computing.

An electron is a little, but very strong magnet. Just imagine that an electron spins on its own axis, either up or down.

Ethan Ahn, Assistant Professor in Electrical Engineering, UTSA

The electronic charge of electrons is used by conventional tech devices for power. In the field of spintronics, scientists tap the inherent spin of electrons as a new source of power. This new strategy will reduce the number of electrons required by the devices to operate.

Nevertheless, there are challenges in tapping the power of spin. In quantum computing that involves tapping the spin of electrons to transfer information, the hurdle for researchers is to find ways to capture spin as efficiently as possible.

If you have 100 electrons injected to the channel to power the next logic circuit, you may only get to use one or two spins because the injection efficiency is very low. This is 98 percent spin lost.

Ethan Ahn, Assistant Professor in Electrical Engineering, UTSA

In order to eliminate the loss of spin, Ahn has come up with the new concept of the “zero-power carbon interconnect,” which involves using nanomaterials as both the tunnel barrier and the spin transport channel. These nanomaterials are similar to a sheet of paper, a 2D layer of carbon atoms with a thickness of just a few nanometers, and it is the point of contact at which spin injection is input into the device. The prototype developed by Ahn is an interconnect developed with a reduced graphene oxide layer.

“It’s novel because we are using graphene, a nanomaterial, to enhance spin injection. By controlling the amount of oxide on the graphene layers, we can fine tune electrons’ conductivity,” stated Ahn.

Graphene has gained considerable attention since it is the strongest nanomaterial in the world. Indeed, the graphene conductivity at room temperature is greater compared to that of any other known material.

If successful, the zero-power carbon interconnect that is being developed by Ahn together with his collaborators at UT-Austin and Michigan State University would be incorporated into the logic component of a computer chip.

Once it is created, the device will be presented to the U.S. Air Force Office of Scientific Research, which has supported UTSA’s study with a three-year grant.

The military needs smaller devices that can operate in remote fields without need to recharge batteries. If our zero-power carbon interconnect is successful, it will improve the efficiency of graphene spintronics—a crucial step in advancing the next generation of low-power electronics like quantum computing.

Ethan Ahn, Assistant Professor in Electrical Engineering, UTSA

This interconnect could also prove highly advantageous to the cloud computing industry. The Data Knowledge Center reports that on-demand cloud computing platforms like the Amazon Web Services alone use up nearly 2% of the nation’s energy. If the zero-power carbon interconnect becomes successful, cloud servers such as those providing streaming services like Netflix or host data could run faster and using less electricity.

Video credit: UTSA