Exploring new spintronics device functionalities in graphene heterostructures

October 17, 2018 by Sian Fogden, Graphene Flagship
Scanning Electron Microscope micrograph of a fabricated device showing the graphene topological insulator heterostructure channel. Credit: Dmitrii Khokhriakov, Chalmers University of Technology

Graphene Flagship researchers have shown in a paper published in Science Advances how heterostructures built from graphene and topological insulators have strong, proximity induced spin-orbit coupling which can form the basis of novel information processing technologies.

Spin-orbit coupling is at the heart of spintronics. Graphene's and high electron mobility make it appealing for long spin coherence length at room temperature. Graphene Flagship researchers from Chalmers University of Technology (Sweden), Catalan Institute of Nanoscience and Nanotechnology—ICN2 (Spain), Universitat Autònoma de Barcelona (Spain) and ICREA Institució Catalana de Recerca i Estudis Avançats (Spain) showed a strong tunability and suppression of the spin signal and spin lifetime in heterostructures formed by and . This can lead to new graphene spintronic applications, ranging from novel circuits to new non-volatile memories and information processing technologies.

"The advantage of using heterostructures built from two Dirac materials is that, graphene in proximity with topological insulators still supports spin transport, and concurrently acquires a strong spin-orbit coupling," said Associate Professor Saroj Prasad Dash from Chalmers University of Technology.

"We do not just want to transport spin we want to manipulate it," said Professor Stephan Roche from ICN2 and deputy leader of the Graphene Flagship's spintronics Work-Package, "the use of topological insulators is a new dimension for spintronics, they have a surface state similar to graphene and can combine to create new hybrid states and new spin features. By combining graphene in this way we can use the tuneable density of states to switch on/off—to conduct or not conduct spin. This opens an active spin device playground."

The Graphene Flagship, from its very beginning, saw the potential of spintronics devices made from graphene and related materials. This paper shows how combining graphene with other materials to make heterostructures opens new possibilities and potential applications.

"This paper combines experiment and theory and this collaboration is one of the strengths of the Spintronics Work-Package within the Graphene Flagship," said Roche.

"Topological insulators belong to a class of material that generate strong spin currents, of direct relevance for spintronic applications such as spin-orbit torque memories. As reported by this article, the further combination of topological insulators with two-dimensional materials like graphene is ideal for enabling the propagation of spin information with extremely low power over long distances, as well as for exploiting complementary functionalities, key to further design and fabricate spin-logic architectures," said Kevin Garello from IMEC, Belgium who is leader of the Graphene Flagships Spintronics Work-Package.

Professor Andrea C. Ferrari, Science and Technology Officer of the Graphene Flagship, and Chair of its Management Panel added "This paper brings us closer to building useful devices. The innovation and technology roadmap of the graphene Flagship recognises the potential of graphene and related materials in this area. This work yet again places the Flagship at the forefront of this field, initiated with pioneering contributions of European researchers."

Explore further: Graphene bilayer provides efficient transport and control of spins

More information: Dmitrii Khokhriakov et al, Tailoring emergent spin phenomena in Dirac material heterostructures, Science Advances (2018). DOI: 10.1126/sciadv.aat9349

Related Stories

Strongly anisotropic spin relaxation observed in graphene

December 8, 2017

Researchers of the ICN2 Physics and Engineering of Nanodevices Group, led by ICREA Prof. Sergio O. Valenzuela, have unambiguously demonstrated the anisotropic nature of spin relaxation in graphene when interfaced with transition ...

Graphene controls surface magnetism at room temperature

October 8, 2018

In a refreshing change of perspective, theoretical physicist Dr. Zeila Zanolli has looked at the proximity effects of graphene on a magnetic semiconducting substrate, finding it to affect the substrate's magnetism down to ...

Spin dynamics of graphene explained through supercomputing

August 2, 2017

In a previous study, researchers found evidence to suggest that spin-orbit coupling (SOC) was greater in graphene/transition metal dichalcogenide heterostructures than in regular graphene. In principle, this phenomenon is ...

Recommended for you

Solving mazes with single-molecule DNA navigators

November 16, 2018

The field of intelligent nanorobotics is based on the great promise of molecular devices with information processing capabilities. In a new study that supports the trend of DNA-based information carriers, scientists have ...

A way to make batteries almost any shape desired

November 16, 2018

A team of researchers from Korea Advanced Institute of Science and Technology, Harvard University and Korea Research Institute of Chemical Technology has developed a way to make batteries in almost any shape that can be imagined. ...

Graphene flickers at 400Hz in 2500ppi displays

November 16, 2018

With virtual reality (VR) sizzling in every electronic fair, there is a need for displays with higher resolution, frame rates and power efficiency. Now, a joint collaboration of researchers from SCALE Nanotech, Graphenea ...

'Smart skin' simplifies spotting strain in structures

November 15, 2018

Thanks to one peculiar characteristic of carbon nanotubes, engineers will soon be able to measure the accumulated strain in an airplane, a bridge or a pipeline – or just about anything – over the entire surface or down ...

1 comment

Adjust slider to filter visible comments by rank

Display comments: newest first

holoman
not rated yet Oct 24, 2018
Modified Faraday effect can change spin also.

https://drive.goo...M57MFVuf

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.