Chalmers University of Technology: Graphene Promising for Future Spintronic Devices


Graphene 041015 spintransitx250Researchers at Chalmers Univ. of Technology have discovered that large area graphene is able to preserve electron spin over an extended period, and communicate it over greater distances than had previously been known. This has opened the door for the development of spintronics, with an aim to manufacturing faster and more energy-efficient memory and processors in computers. The findings are published in Nature Communications.

“We believe that these results will attract a lot of attention in the research community and put graphene on the map for applications in spintronic components,” says Saroj Dash, who leads the research group at Chalmers Univ. of Technology.

Spintronics is based on the quantum state of the electrons, and the technology is already being used in advanced hard drives for data storage and magnetic random accesses memory. But here the spin-based information only needs to move a few nanometers, or millionths of a millimetre. Which is lucky, because spin is a property in electrons that in most materials is extremely short-lived and fragile.

However, there are major advantages in exploiting spin as an information carrier, instead of, or in addition to electric charges. Spintronics could make processors significantly faster and less energy consuming than they are today.

Graphene is a promising candidate for extending the use of spintronics in the electronics industry. The thin carbon film is not only an excellent electrical conductor, but also theoretically has the rare ability to maintain the electrons with the spin intact.

“In future spin-based components, it is expected that the electrons must be able to travel several tens of micrometers with their spins kept aligned. Metals, such as aluminum or copper, do not have the capacity to handle this. Graphene appears to be the only possible material at the moment,” says Saroj Dash.

Graphene 041015 spintransitx250

 In graphene, electrons keep their magnetization, their spin (the pink arrows in the picture) much longer than they do in ordinary conductors such as copper and aluminum. This characteristic of graphene may enable spintronics to become a complement to traditional electronics, which only utilizes one of the electron´s degrees of freedom, namely their charge. Image: M Venkata Kamalakar et al, Nature Communications

Today, graphene is produced commercially by a few companies using a number of different methods, all of which are in an early phase of development.

Put simply, you could say that high-quality graphene can only be obtained in very small pieces, while larger graphene is produced in a way that the quality is either too low or has other drawbacks from the perspective of the electronics industry.

But that general assumption is now being seriously questioned by the findings presented by the research group at Chalmers. They have conducted their experiments using CVD graphene, which is produced through chemical vapor deposition. The method gives the graphene a lot of wrinkles, roughness and other defects.

But it also has advantages: There are good prospects for the production of large area graphene on an industrial scale. The CVD graphene can also be easily removed from the copper foil on which it grows and is lifted onto a silicon wafer, which is the semiconductor industry’s standard material.

Although the quality of the material is far from perfect, the research group can now show parameters of spin that are up to six times higher than those previously reported for CVD graphene on a similar substrate.

“Our measurements show that the spin signal is preserved in graphene channels that are up to 16 micrometers long. The duration over which the spins stay aligned has been measured to be over a nanosecond,” says Chalmers researcher Venkata Kamalakar who is the article’s first author.

“This is promising because it suggests that the spin parameters can be further improved as we develop the method of manufacturing.

That researchers are focusing on how far the spin current can be communicated should not be thought of as just being about sending information in a new material or replacing metals or semiconductors with graphene. The goal instead is a completely new way of performing logical operations and storing information. A concept that, if successful, would take digital technology a step beyond the current dependence on semiconductors.

“Graphene is a good conductor and has no band gaps. But in spintronics there is no need for band gaps to switch between on and off, one and zero. This is controlled instead by the electron’s up or down spin orientations,” Saroj Dash explains.

A short-term goal now is to construct a logical component that, not unlike a transistor, is made up of graphene and magnetic materials.

Whether spintronics can eventually fully replace semiconductor technology is an open question, a lot of research remains. But graphene, with its excellent spin conduction abilities, is highly likely to feature in this context.

Source: Chalmers Univ. of Technology

Graphene Commercialisation and Applications: Global Industry and Academia Summit


QDOTS imagesCAKXSY1K 8(Nanowerk News) From its high electrical conductivity  and structural strength, graphene has been cited as a “wonder material” with the  potential to revolutionize materials engineering in many different industrial  sectors. While the number of commercial applications for graphene is potentially  unlimited, production scalability must first be established and R&D activity  properly directed to ensure graphene moves out of the lab and into the market.

The Graphene Commercialisation & Applications:  Global Industry & Academia Summit 2013, (25th-26th June, 2013, London),  is the first forum of its kind aimed at establishing the real, commercially  viable industrial applications of graphene, and expediting its role as a  game-changing technology.

With trailblazing companies such as Nokia, Head, Samsung,  Philips, BAE Systems, Sony and Thales, as well as leading academic and research  institutions such as Manchester University, UCLA, Chalmers University, Seoul  National University and Fraunhofer IPA, coming together for the first time to  present their views, this exciting event is a timely opportunity for relevant  stakeholders to evaluate specific industry requirements for graphene, as well as  understanding its’ material capabilities and real world applications.

Senior Business And Scientific Leaders Speaking At The Summit  Include

  • – Jari Kinaret, Professor, Chalmers University and Director, Graphene Flagship  Consortium
  • – James Baker, Managing Director, BAE Systems Advanced Technology Centre
  • – Jani Kivioja, Research Leader, Nokia
  • – Ralf Schwenger, Director R&D Raquetsports, Head Sport
  • – Seungmin Cho, Principal Research Engineer and Group Leader, Samsung Techwin
  • – Byung Hee Hong, Associate Professor, Seoul National University
  • Richard Kaner, Professor of Chemistry, UCLA
  • – Paolo Bondavalli, Head of Nanomaterial Topic, Thales Group
  • – Marcello Grassi, Head of Technology, Spirit AeroSystems Europe
  • – Nuno Lourenco, Head of Technology, UTC Aerospace
  • – York Haemisch, Senior Director Corporate Technologies, Philips Research
  • – Peter Fischer, CTO, Plastic Logic
  • – Antonio Avitabile, Head of Strategic Technology Partnerships, Sony
  • – Ivica Kolaric, Department Head, Fraunhofer IPA
  • – Pradyumna Goli – Research Associate, A.A. Ballandin Nano-Device Laboratory, UC  Riverside
  • – Rahul Nair, Lead Researcher, University of Manchester
  • – Craig Poland, Research Scientist, Institute of Occupational  Medicine

Day One of the Summit will establish graphene’s commercially  viable applications across multiple sectors and the commercialisation roadmap.

Day Two illustrates supply and cost projections as well as  production scalability steps.

Download The Full Agenda And Speaker Faculty  HereThis forum will provide a unique and invaluable opportunity to  gain insights into the opportunities and hindrances presented by graphene. It  will also provide the framework for industry, research and academia to  collaborate in making this revolutionary technological development a market  reality.

Click Here To Register, Saving £200 Per Person By  19th AprilIf you would like more information about joining the exhibition  showcase or require information on group registration discounts, then please  contact the team on +44 (0) 800 098 8489 or email  info@london-business-conferences.co.uk

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