Innovative research on ferrimagnetic materials earns over $2.5M in funding to advance communication technologies

By Georgia Jackson, College of Arts and Sciences

Two grants awarded to faculty in the Department of Physics will support research on ferrimagnetic materials and their potential applications
in advancing communication technologies. Both awards, which together account for more
than $2.5M in research funding, will support graduate students and expose numerous
undergraduates to advanced research methods as they work with faculty to bridge what
physicists refer to as the “terahertz gap.”

A ‘new spin’ on an old material 

Human use of ferrimagnetic materials — or magnetic materials that contain opposing
magnetic moments — dates back to at least 600 B.C.E., when ferrimagnets were used
in religious ceremonies and to create early compasses. According to Darío Arena, an associate professor in the Department of Physics, the material may also be the
key to bridging the “terahertz gap,” or the gap, on the electromagnetic spectrum,
between microwaves and infrared light. 

“You’ve got this problem, where optics don’t work well and you can’t have everyone
connected through a fiber connection, and the electronics start to peter out,” said
Arena. “We are trying to use these ferrimagnetic materials to bridge that gap.” 

Solving the problem, which would mean faster and more secure modes of communication,
is a high priority for organizations like the Air Force Research Laboratory (AFRL),
who awarded Arena, along with faculty from the University of Central Florida, Morgan
State University and the City University of New York, $2.25M to collaborate over the
next three years. 
 
“These are old materials, and we’re trying to put a new spin on them,” said Arena,
who will serve as co-principal investigator for the multimillion-dollar grant. 
 
When it comes to ferrimagnets, spin is important. 

“Almost all of the electronics that we’re used to, including technologies related
to the internet, are based on moving electrons around,” Arena said. “Spintronics tries
to use this other property of electrons called ‘spin.’ That would have a lot of potential
benefits for high-speed communication, considerably lower power consumption and potential
new functionality that you can’t get with the standard movement of electrons.”

Unlocking new technologies

Arena will also serve as principal investigator on a second grant of $489,964 from
the National Science Foundation that will support department faculty in their attempt
to control the spin of electrons by combining ferrimagnets with two-dimensional transition
metal dichalcogenides (TMDs), which can serve as semiconductors — like the materials
used to make the LEDs found in many high-resolution televisions and computer screens. 

“I hope to one day be able to buy an iPhone with some of these combinations of materials
in it,” said Arena.

“What we’re trying to do with this combination of ferrimagnets and these specific
types of semiconductors called TMDs is what’s called ‘spin injection,’” Arena said.
“If we can inject the spin from the ferrimagnet into the semiconductor, it will emit
light with a property called ‘circular polarization.’” 
 
Think of the emitted light’s electronic field like a spiral staircase. It can either
wrap to the right or wrap to the left. 
 
“It’s not an easy thing to control,” said Arena, who will be joined by associate professors
Humberto Rodriquez Gutierrez and Andreas Muller. “But we think this is a good combination of material systems to get that to work.”
 
 
If they succeed, they will unlock new technical capabilities including ultrahigh speed
optical communications, three-dimensional displays, quantum encryption and other quantum
information applications, and secure long-range communication. 
 
“I hope to one day be able to buy an iPhone with some of these combinations of materials
in it,” said Arena, who is also looking forward to introducing students and postdoctoral
candidates to the cutting-edge ferrimagnetic research.