A University of Utah-led team has discovered that a class of “miracle materials” called organic-inorganic hybrid perovskites could be a game changer for future spintronic devices.
Spintronics uses the direction of the electron spin — either up or down — to carry information in ones and zeros. A spintronic device can process exponentially more data than traditional electronics that use the ebb and flow of electrical current to generate digital instructions. But physicists have struggled to make spintronic devices a reality.
The new study, published online today in Nature Physics, is the first to show that organic-inorganic hybrid perovskites are a promising material class for spintronics. The researchers discovered that the perovskites possess two contradictory properties necessary to make spintronic devices work — the electrons’ spin can be easily controlled, and can also maintain the spin direction long enough to transport information, a property known as spin lifetime.
“It’s a device that people always wanted to make, but there are big challenges in finding a material that can be manipulated and, at the same time, have a long spin lifetime,” says Sarah Li, assistant professor in the Department of Physics & Astronomy at the U and lead author of the study. “But for this material, it’s the property of the material itself that satisfies both.”
The miracle material
Organic-inorganic hybrid perovskites is already famous in scientific circles for being amazingly efficient at converting sunlight into electricity.
“It’s unbelievable. A miracle material,” says Z. Valy Vardeny, distinguished professor in the Department of Physics & Astronomy and co-author of the study, whose lab studies perovskite solar cells. “In just a few years, solar cells based on this material are at 22 percent efficiency. And now it has this spin lifetime property. It’s fantastic.”
The material’s chemical composition is an unlikely candidate for spintronics, however. The hybrid perovskite inorganic frame is made of heavy elements. The heavier the atom, the easier it is to manipulate the electron spin. That’s good for spintronics. But other forces also influence the spin. When the atoms are heavy, you assume the spin lifetime is short, explains Li.
“Most people in the field would not think that this material has a long spin lifetime. It’s surprising to us, too,” says Li. “We haven’t found out the exact reason yet. But it’s likely some intrinsic, magical property of the material itself.”
Spintronics: That magnetic moment when…
Cellphones, computers and other electronics have silicon transistors that control the flow of electrical currents like tiny dams. As devices get more compact, transistors must handle the electrical current in smaller and smaller areas.
“People were thinking, ‘How do we increase the amount of information in such a small area?’” adds Vardeny. “What do we do to overcome this limit?”
“Spintronics,” answers physics.
Spintronics uses the spin of the electron itself to carry information. Electrons are basically tiny magnets orbiting the nucleus of an element. Just like the Earth has its own orientation relative to the sun, electrons have their own spin orientation relative to the nucleus that can be aligned in two directions: “Up,” which represents a one, and “down,” which represents a zero. Physicists relate the electron’s “magnetic moment” to its spin.
By adding spin to traditional electronics, you can process exponentially more information than using them classically based on less or more charge.
“With spintronics, not only have you enormously more information, but you’re not limited by the size of the transistor. The limit in size will be the size of the magnetic moment that you can detect, which is much smaller than the size of the transistor nowadays,” says Vardeny.
The experiment to tune electron spin
Tuning an electron spin is like tuning a guitar, but with a laser and a lot of mirrors.
They split the laser into two beams; the first one hit the film to set the electron spin in the desired direction. The second beam bends through a series of mirrors like a pinball machine before hitting the perovskite film at increasing time intervals to measure how long the electron held the spin in the prepared direction.
They found that the perovskite has a surprisingly long spin lifetime — up to nanosecond. The spin flips many times during one nanosecond, which means a lot information can be easily stored and manipulated during that time.
Once they determined the long spin lifetime, the researchers tested how well they could manipulate the spin with a magnetic field.
“The spin is like the compass. The compass spins in this magnetic field perpendicular to that compass, and eventually it will stop spinning,” says Li. “Say you set the spin to ‘up,’ and you call that ‘one.’ When you expose it to the magnetic field, the spin changes direction. If it rotated 180 degrees, it changes from one to zero. If it rotated 360 degrees, it goes from one to one.”
They found that they could rotate the spin more than 10 turns by exposing the electron to different strengths of magnetic field.
The potential for this material is enormous, says Vardeny. It could process data faster and increase random-access memory.
“I’m telling you, it’s a miracle material,” says Vardeny.
Learn more: A NEW SPIN ON ELECTRONICS
The Latest on: Spintronics
- Nano electronics Market Demand is Increasing Rapidly in 2016 - 2026 on August 18, 2017 at 10:14 pm
Another factor driving this Nano electronics market is the development of Spintronics with Nano Electronics that will help in the development of spin based computing in coming year. This his technology is still in its introductory phase therefore there is ... […]
- Atomically Thin Layers Bring Spintronics Closer to Applications on August 17, 2017 at 9:29 am
University of Groningen scientists led by physics professor Bart van Wees have created a graphene-based device, in which electron spins can be injected and detected with unprecedented efficiency. The result is a hundredfold increase of the spin signal, big ... […]
- On-Surface Oligomerization of Self-Terminating Molecular Chains for the Design of Spintronic Devices on August 16, 2017 at 5:01 pm
Molecular spintronics is currently attracting a lot of attention due to its great advantages over traditional electronics. A variety of self-assembled molecule-based devices are under development, but studies regarding the reliability of the growth-process ... […]
- Graphene Nanochem : University of Groningen - Atomically thin layers bring spintronics closer to applications on August 16, 2017 at 3:41 am
Release date- 15082017 - University of Groningen scientists led by physics professor Bart van Wees have created a graphene-based device, in which electron spins can be injected and detected with unprecedented efficiency. 'Spin' is a magnetic property of ... […]
- A graphene and boron nitride heterostructure creates large spin signals on August 15, 2017 at 4:46 am
The reported observation takes graphene spintronics to the qualitatively new level." Spintronics focuses on room temperature graphene spintronic devices, joining together theoretical and experimental research, and is seen as a long-term investment for the ... […]
- Transporting spin: A graphene and boron nitride heterostructure creates large spin signals on August 15, 2017 at 3:11 am
The reported observation takes graphene spintronics to the qualitatively new level.' Spintronics is one of the work packages in the Graphene Flagship where Professor van Wees is the leader. It focuses on investigating room temperature graphene spintronic ... […]
- Computer tech: 'Organismic learning' mimics some aspects of human thought on August 14, 2017 at 5:00 pm
Organismoids might have applications in the emerging field of spintronics. Conventional computers use the presence and absence of an electric charge to represent ones and zeroes in a binary code needed to carry out computations. Spintronics, however ... […]
- Surprise discovery in energy efficient information storage on August 10, 2017 at 7:44 pm
The research carried out by researchers in the Spintronics Group in the School of Physics and Astronomy, in collaboration with York University, has been published in the open access journal Scientific Reports. Dr Andrew Rushforth, from the School of ... […]
- Sydney Pratt Wins Summer Research Grant on August 10, 2017 at 10:50 am
Central College senior Sydney Pratt won a research grant to study spintronics with assistant professor of physics Liz Golovatski. To view these students click here: http://central.meritpages.com/achievements/Sydney-Pratt-Wins-Summer-Research-Grant/77781 […]
- The Electron Manifesto: transforming high performance computing with 'spintronics' on August 7, 2017 at 8:07 am
via Google News and Bing News