Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Spinning around: A room temperature field-effect transistor using graphene's electron spin

06.07.2017

Graphene Flagship researchers based at Chalmers University of Technology in Gothenburg, Sweden have published in Nature Communications a research paper showing a graphene-based spin field-effect transistor operating at room temperature. Using the spin of the electrons in graphene and other layered material heterostructures the researchers have produced working devices as a step towards integrating spintronic logic and memory devices.

Current semiconductor logic devices within our computers use the flow and control of electronic charge for information processing. Spintronic memory devices use the intrinsic properties of electron spin to store information. For future devices, researchers are searching for ways to integrate both information processing and storage in one device unit.


This is a schematic of graphene-MoS2 heterostructure which allows spin injection into graphene from the ferromagnetic source, diffusive spin transport in the graphene-MoS2 heterostructure channel, spin manipulation by a gate voltage and detection of spin signal by the ferromagnetic drain.

Credit: Spin FET@Chalmers

"Graphene is an excellent medium for spin transport at room temperature, due to its low atomic mass. However, an unsolved challenge was to control the spin current at ambient temperature" explains Saroj Dash, group leader and Associate Professor at Chalmers University of Technology.

The Graphene Flagship researchers Andre Dankert and Saroj Dash have now shown that it is possible to electrically manipulate the spin properties of graphene in a controlled manner at room temperature. This not only could open many new possibilities in spin logic operations but also integration with magnetic memory elements in a single device. With further developments, if one could produce a spin current without charge flow, this will require far less power and lead to more versatile devices. This is especially important as we move more and more toward hand held mobile computing.

"Controlling the flow of spin currents in a transistor-like manner is a decade old dream and the missing link towards all-electrical spin logic applications." says the lead author Andre Dankert from Chalmers University of Technology, "Researchers were working for almost ten years to understand the spin transport properties of various layered materials and how they can be tuned to achieve this goal. Our work is an important milestone in the field of spintronics."

Graphene has been shown to transport spin over long distances by several Flagship Groups. Combining graphene with another layered material where spin lasts much less time can produce a spin field-effect transistor like device.

Talking about creating spintronic devices using a heterostructure is Saroj Dash, "By combining graphene, where spin lasts for nano seconds with molybdenum disulfide where spin only lasts for picoseconds you can control where the spin can go by using a gate voltage - essentially you can create a spin switch. Importantly, we show in this research a particular materials mix which enables this spin-switch to work at room temperature."

Saroj Dash also added "We have been working on graphene spintronics for a number of years and we joined the Graphene Flagship because our goals are aligned with that of the Flagship spintronics work package -- to investigate room temperature graphene spintronics devices, joining together theoretical and experiment research. The collaborative nature of the Graphene Flagship community, with its focus on face to face meetings has lead to many fruitful discussions within our spintronics field. This collaborative approach also led to a great relationship with our commercial partner Graphenea, who has worked with us to provide the graphene sample we needed."

Speaking about the next steps in his research Andre Dankert said, "Now we know the crucial parameters of our device structure, we can optimise it to increase the effective gain and transistor action."

Many layered materials are promising for spintronics. In addition to exploring the interesting properties of these individual crystals, it is intriguing to reveal the potential of their heterostructures. The bigger goal is to create novel spin phenomena in layered materials based devices by stacking different layers with complementary properties, Saroj Dash explained.

Bart van Wees, leader of the spintronics work package adds, "The future challenge will be to explore and use the new spintronic functionalities which are made possible by the new van der Waals heterostructures. The authors already made an important step here."

Professor Andrea Ferrari, Chair of the Management Panel and Science and Technology Officer of the Graphene Flagship added: "spintronics has been one of the fundamental work packages since the start of the Flagship. It was always seen as a long term investment. It is exciting to see that so much progress has been made towards devices"

###

For further reading on spintronic devices please see this 2013 Graphene Flagship piece: From Science to Technology, Graphene Spintronics.

Media Contact

Sian Fogden
comms@graphene.cam.ac.uk
44-012-237-62418

 @GrapheneCA

http://graphene-flagship.eu 

Sian Fogden | EurekAlert!

More articles from Physics and Astronomy:

nachricht Subaru Telescope helps pinpoint origin of ultra-high energy neutrino
16.07.2018 | National Institutes of Natural Sciences

nachricht Nano-kirigami: 'Paper-cut' provides model for 3D intelligent nanofabrication
16.07.2018 | Chinese Academy of Sciences Headquarters

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Subaru Telescope helps pinpoint origin of ultra-high energy neutrino

16.07.2018 | Physics and Astronomy

Barium ruthenate: A high-yield, easy-to-handle perovskite catalyst for the oxidation of sulfides

16.07.2018 | Life Sciences

New research calculates capacity of North American forests to sequester carbon

16.07.2018 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>