Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


How to make the wonder material graphene superconducting

Whenever a new material is discovered, scientists are eager to find out whether or not it can be superconducting.

This applies particularly to the wonder material graphene. Now, an international team around researchers at the University of Vienna unveiled the superconducting pairing mechanism in Calcium doped graphene using the ARPES method. Their results are published in the reputed journal Nature Communications.

This image shows ARPES measurements of Calcium doped graphene. Left: the Fermi surface of graphene (top) and the Dirac cone (bottom). Right: The kink in the spectral function in the two crystallographic main directions. The scientists analyzed the strength of the kink in order to estimate the superconducting critical temperature.

Credit: Copyright: A. Grüneis and A.V. Fedorov

Superconducting materials exhibit an invaluable feature when cooled below a critical temperature – they allow the transport of an electric current without loss. Superconductivity is based on the fact that in certain materials electrons can pair up which – at a higher temperature – would otherwise repel each other. Scientists from the Electronic Properties of Materials Group at the Faculty of Physics (University of Vienna) and their collaboration partners teamed up to uncover the potential superconducting coupling mechanism of the wonder material graphene.

Graphene, a single-atom thick layer of carbon atoms was discovered in 2004 and is regarded as one of the most amazing and versatile substances available to mankind. The impact of the first real two-dimensional material is so significant that a Nobel Prize was awarded for its discovery. Until recently, there were no experimental reports of superconductivity in graphene although its close relatives, graphite and fullerenes can be made superconducting by intentionally introducing electrons in the material (doping).

The ARPES method – how light sheds light on superconductivity

In order to shed light on superconductivity in graphene, the scientists resorted to the powerful photoemission method: when a light particle interacts with a material it can transfer all its energy to an electron inside that material. If the energy of the light is sufficiently large, the electron acquires enough energy to escape from the material. Determining the angle under which the electrons escape from the material enables the scientists to extract valuable information on the electronic properties and the complex many-body interactions of the material.

Nikolay Verbitskiy and Alexander Grüneis from the University of Vienna together with Alexander Fedorov and Denis Vyalikh from IFW-Dresden and TU-Dresden and Danny Haberer from the University of California at Berkeley and their colleagues employed this technique – the so-called Angle-resolved photoemission spectroscopy (ARPES) – at the Elettra synchrotron in Trieste where they researched the interaction of a series of electron dopants (Cs, Rb, K, Na, Li, Ca) with monolayer graphene.

Who makes the grade?

According to the findings of the scientists, calcium is the most promising candidate to induce superconductivity in graphene with a critical temperature of about 1.5K. This critical temperature is rather low compared to e.g. fullerenes which superconduct at 33K. However, graphene offers several huge advantages over many other materials. Since it consists only of carbon atoms arranged in single layers, it is easy to be chemically functionalized. Moreover, it can be grown in multiple numbers of atom layers in various stacking orders and can be doped in several different ways. Thereby, it gives a multitude of options to experiment with.

The scientists are confident that, while graphene will not set new record critical temperatures, the ease by which its properties can be modified will enhance our understanding of superconductivity in general and carbon materials in particular.


Observation of a universal donor-dependent vibrational mode in grapheme: A.V. Fedorov, N.I. Verbitskiy, D. Haberer, C. Struzzi, L. Petaccia, D. Usachov, O.Y. Vilkov, D.V. Vyalikh, J. Fink, M. Knupfer, B. Büchner & A. Grüneis. Nature Communications | 5:3257 | DOI: 10.1038/ncomms4257.

Alexander Grüneis | EurekAlert!
Further information:

More articles from Materials Sciences:

nachricht Researchers demonstrate existence of new form of electronic matter
15.03.2018 | University of Illinois at Urbana-Champaign

nachricht Boron can form a purely honeycomb, graphene-like 2-D structure
15.03.2018 | Science China Press

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Locomotion control with photopigments

Researchers from Göttingen University discover additional function of opsins

Animal photoreceptors capture light with photopigments. Researchers from the University of Göttingen have now discovered that these photopigments fulfill an...

Im Focus: Surveying the Arctic: Tracking down carbon particles

Researchers embark on aerial campaign over Northeast Greenland

On 15 March, the AWI research aeroplane Polar 5 will depart for Greenland. Concentrating on the furthest northeast region of the island, an international team...

Im Focus: Unique Insights into the Antarctic Ice Shelf System

Data collected on ocean-ice interactions in the little-researched regions of the far south

The world’s second-largest ice shelf was the destination for a Polarstern expedition that ended in Punta Arenas, Chile on 14th March 2018. Oceanographers from...

Im Focus: ILA 2018: Laser alternative to hexavalent chromium coating

At the 2018 ILA Berlin Air Show from April 25–29, the Fraunhofer Institute for Laser Technology ILT is showcasing extreme high-speed Laser Material Deposition (EHLA): A video documents how for metal components that are highly loaded, EHLA has already proved itself as an alternative to hard chrome plating, which is now allowed only under special conditions.

When the EU restricted the use of hexavalent chromium compounds to special applications requiring authorization, the move prompted a rethink in the surface...

Im Focus: Radar for navigation support from autonomous flying drones

At the ILA Berlin, hall 4, booth 202, Fraunhofer FHR will present two radar sensors for navigation support of drones. The sensors are valuable components in the implementation of autonomous flying drones: they function as obstacle detectors to prevent collisions. Radar sensors also operate reliably in restricted visibility, e.g. in foggy or dusty conditions. Due to their ability to measure distances with high precision, the radar sensors can also be used as altimeters when other sources of information such as barometers or GPS are not available or cannot operate optimally.

Drones play an increasingly important role in the area of logistics and services. Well-known logistic companies place great hope in these compact, aerial...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

Ultrafast Wireless and Chip Design at the DATE Conference in Dresden

16.03.2018 | Event News

International Tinnitus Conference of the Tinnitus Research Initiative in Regensburg

13.03.2018 | Event News

International Virtual Reality Conference “IEEE VR 2018” comes to Reutlingen, Germany

08.03.2018 | Event News

Latest News

Wandering greenhouse gas

16.03.2018 | Earth Sciences

'Frequency combs' ID chemicals within the mid-infrared spectral region

16.03.2018 | Physics and Astronomy

Biologists unravel another mystery of what makes DNA go 'loopy'

16.03.2018 | Life Sciences

Science & Research
Overview of more VideoLinks >>>