鲍鱼tv

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 鈥渢erahertz gap.鈥�

A 鈥榥ew spin鈥� on an old material 

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

鈥淵ou鈥檝e got this problem, where optics don鈥檛 work well and you can鈥檛 have everyone connected through a fiber connection, and the electronics start to peter out,鈥� said Arena. 鈥淲e are trying to use these ferrimagnetic materials to bridge that gap.鈥� 

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. 
 
鈥淭hese are old materials, and we鈥檙e trying to put a new spin on them,鈥� said Arena, who will serve as co-principal investigator for the multimillion-dollar grant. 
 
When it comes to ferrimagnets, spin is important. 

鈥淎lmost all of the electronics that we鈥檙e used to, including technologies related to the internet, are based on moving electrons around,鈥� Arena said. 鈥淪pintronics tries to use this other property of electrons called 鈥榮pin.鈥� That would have a lot of potential benefits for high-speed communication, considerably lower power consumption and potential new functionality that you can鈥檛 get with the standard movement of electrons.鈥�

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 鈥� like the materials used to make the LEDs found in many high-resolution televisions and computer screens. 

鈥淚 hope to one day be able to buy an iPhone with some of these combinations of materials in it,鈥� said Arena.

鈥淲hat we鈥檙e trying to do with this combination of ferrimagnets and these specific types of semiconductors called TMDs is what鈥檚 called 鈥榮pin injection,鈥欌�� Arena said. 鈥淚f we can inject the spin from the ferrimagnet into the semiconductor, it will emit light with a property called 鈥榗ircular polarization.鈥欌�� 
 
Think of the emitted light鈥檚 electronic field like a spiral staircase. It can either wrap to the right or wrap to the left. 
 
鈥淚t鈥檚 not an easy thing to control,鈥� said Arena, who will be joined by associate professors Humberto Rodriquez Gutierrez and Andreas Muller. 鈥淏ut we think this is a good combination of material systems to get that to work.鈥�  
 
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. 
 
鈥淚 hope to one day be able to buy an iPhone with some of these combinations of materials in it,鈥� said Arena, who is also looking forward to introducing students and postdoctoral candidates to the cutting-edge ferrimagnetic research.