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
- Giant Spin Anisotropy in Graphene Could Pave the Way for New Spintronic Logic Devices on December 12, 2017 at 5:46 am
The unique tuneable electronic properties of graphene make it a perfect material for spintronics applications. Spearheading the way in three recent papers, the Flagship research team has demonstrated that GRMs can be integrated to create an unparalleled ... […]
- Graphene spin transport takes a step forward towards applications on December 11, 2017 at 10:04 am
Engaged as part of the Flagship's dedicated Spintronics work package, the teams maintain close relationships and determine common goals, benefitting from the Flagship's unique approach to collaborative, interdisciplinary research. "This is a nice example ... […]
- A magnetic tip reconfigures edge states on December 7, 2017 at 11:14 am
The existence of chiral edge states along the domain walls was confirmed with electrical transport measurements. The ability to reconfigure and manipulate these states may improve spintronics. […]
- EPFL Measures Electron Properties In 2D Semiconductors on December 6, 2017 at 1:46 am
A group of spintronics researchers at EPFL (Ecole Polytechnique Federale de Lausanne) have quantified the quantum properties in electrons in a a series of 2D semiconductors. Led by Andras Kis who runs the Laboratory of Nanoscale Electronics and Structures ... […]
- NUS Engineering Researchers Achieve a Major Breakthrough in Spintronics Research on November 29, 2017 at 7:59 am
Realization of room temperature spin-orbit torque driven magnetization switching in topological insulator-ferromagnet heterostructures is considered to have promising applications in high integration density memories and logic devices and low power ... […]
- Global Semiconductor Spintronics Market Comparison by Types, Application and by Regions on November 21, 2017 at 4:00 pm
(EMAILWIRE.COM, November 22, 2017 ) The Global Semiconductor Spintronics Industry 2017 Market Research Report is a professional and in-depth study on the current state of the Semiconductor Spintronics industry. With around 150 tables and figures this ... […]
- New material bismuthene could boost spintronics information technology on July 10, 2017 at 12:26 pm
Researchers have developed a new material called bismuthene, which could make the concept of spintronic information transmission far more viable, as it can operate effectively at room temperature. Said to possess similar properties to the wonder material ... […]
- Shift from electronics to spintronics opens up possibilities of faster data on September 1, 2015 at 10:35 pm
Atsufumi Hirohata receives funding from EPSRC (EP/I000933/1, EP/K03278X/1 and EP/M02458X/1), Royal Society Industry Fellowship and EU FP-7 (NMP3-SL-2013-604398). Electronics is based on measuring the tiny electrical charge of electrons passing through ... […]
- Challenges for organic spintronics on September 4, 2013 at 5:51 am
Researchers aiming to utilize these processes for new organic spintronics devices should focus more on scrutinizing these models experimentally by embracing spectroscopy. We offer a brief critical perspective of the state of affairs of organic spintronics ... […]
via Google News and Bing News