Nav: Home

Spinning better electronic devices

March 02, 2016

RIVERSIDE, Calif. ( -- A team of researchers, led by a group at the University of California, Riverside, have demonstrated for the first time the transmission of electrical signals through insulators in a sandwich-like structure, a development that could help create more energy efficient electronic devices.

Conventional electronic devices rely on the transport of electrons in a semiconductor such as silicon. Now, researchers are exploiting the 'spin' of the electron rather than its charge to create a new generation of 'spintronic' devices that are potentially more energy efficient and more versatile than those currently making up silicon chips and circuit elements.

The UC Riverside-led research, which was published online Wednesday (March 2) in the journal Nature Communications, is significant because it demonstrates that a tri-layer, sandwich-like, structure can serves as a scalable pure spin current device, an essential ingredient in spintronics.

A key element in this breakthrough is the material. To demonstrate the effect, the magnetic insulator needs to be truly insulating, or there will be a parasitic signal from leakage. On the other hand, a high-quality magnetic insulator grown on metal had never been demonstrated.

Using combination of sputtering (for metals) and pulsed laser deposition (for insulator), we successfully showed that the 50-100 nanometer thick magnetic insulator, such as yttrium iron garnet, is not only magnetic and insulating, but also of high quality when it is grown on 5 nanometer thick platinum.

In the structures used by the researchers, there are two metals and a magnetic insulator in between. The metals are for spin current generation and detection (conversion of spin current back to charge current) via the so-called spin Hall effect and inverse spin Hall effect.

The magnetic insulator is an electrical insulator but a good spin current conductor. The spin current flowing in the insulator does not involve mobile electrons therefore it does not dissipate energy as an electrical current does in joule heating.

The researchers have also demonstrated that the signal transmission can be switched on and off and modulated in its strength by a magnetic field. The electrical signal transmission through the magnetic insulators can be switched on and off depending on the magnetic state, or direction of the magnetization, of the magnetic insulators.

So the direction of the magnetization can be regarded as a memory state of non-volatile random access memory devices. In addition, the signal level can be modulated by changing the direction of the magnetization; therefore, it can also be used as analog devices. The sandwich structure can be made small by nanofabrication so that the devices can be scaled down.
The paper is called "Observation of magnon-mediated current drag in Pt/yttrium iron garnet/Pt(Ta)trilayers." The authors are Jing Shi, a UC Riverside physics professor; five members of his lab, Junxue Li, Yadong Xu, Mohammed Aldosary, Chi Tang and Zhisheng Lin; Roger Lake, a UC Riverside professor of electrical and computer engineering; and Shufeng Zhang, a physics professor at the University of Arizona.

The paper is the first major collaborative result from the SHINES (Spins and Heat In Nanoscale Electronic Systems) center, an Energy Frontier Research Center funded with a $12 million grant from the U.S. Department of Energy (Award #SC0012670.)

Zhang's work was supported by the National Science Foundation (Award #F1404542.)

The UC Riverside Office of Research and Economic Development has filed a provisional patent application related to this research.

University of California - Riverside

Related Electrons Articles:

Cooling nanotube resonators with electrons
In a study in Nature Physics, ICFO researchers report on a technique that uses electron transport to cool a nanomechanical resonator near the quantum regime.
New method for detecting quantum states of electrons
Researchers in the Quantum Dynamics Unit at the Okinawa Institute of Science and Technology Graduate University (OIST) devised a new method -- called image charge detection -- to detect electrons' transitions to quantum states.
Slow electrons to combat cancer
Slow electons can be used to destroy cancer cells - but how exactly this happens has not been well understood.
How light steers electrons in metals
Researchers in the Department of Physics of ETH Zurich have measured how electrons in so-called transition metals get redistributed within a fraction of an optical oscillation cycle.
Twisting whirlpools of electrons
Using a novel approach, EPFL physicists have been able to create ultrafast electron vortex beams, with significant implications for fundamental physics, quantum computing, future data-storage and even certain medical treatments.
Inner electrons behave differently in aromatic hydrocarbons
In an international research collaboration between Tsinghua University in Beijing and Sorbonne University in Paris, scientists found that four hydrocarbon molecules, known for their internal ring structure, have a lower threshold for the release of excess energy than molecules without a similar ring structure, because one of their electrons decays from a higher to a lower energy level, a phenomenon called the Auger effect.
Exotic spiraling electrons discovered by physicists
Rutgers and other physicists have discovered an exotic form of electrons that spin like planets and could lead to advances in lighting, solar cells, lasers and electronic displays.
Racing electrons under control
The advantage is that electromagnetic light waves oscillate at petaherz frequency.
Electrons go with the flow
You turn on a switch and the light switches on because electricity 'flows'.
Tying down electrons with nanoribbons
Nanoribbons are promising topological materials displaying novel electronic properties. UC Berkeley chemists and physicists have found a way to join two different types of nanoribbon to create a topological insulator that confines single electrons to the junction between them.
More Electrons News and Electrons Current Events

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Rethinking Anger
Anger is universal and complex: it can be quiet, festering, justified, vengeful, and destructive. This hour, TED speakers explore the many sides of anger, why we need it, and who's allowed to feel it. Guests include psychologists Ryan Martin and Russell Kolts, writer Soraya Chemaly, former talk radio host Lisa Fritsch, and business professor Dan Moshavi.
Now Playing: Science for the People

#538 Nobels and Astrophysics
This week we start with this year's physics Nobel Prize awarded to Jim Peebles, Michel Mayor, and Didier Queloz and finish with a discussion of the Nobel Prizes as a way to award and highlight important science. Are they still relevant? When science breakthroughs are built on the backs of hundreds -- and sometimes thousands -- of people's hard work, how do you pick just three to highlight? Join host Rachelle Saunders and astrophysicist, author, and science communicator Ethan Siegel for their chat about astrophysics and Nobel Prizes.