Graphene Exhibits Electron Partitioning Process
November 20, 2015 | Osaka UniversityEstimated reading time: 2 minutes
Graphene, a single atomic layer of graphite with a carbon-layered structure, has been drawing much attention because of its abundant electronic properties and the possibilities of application due to its unique electronic structure. Andre Geim and Konstantin Novoselov extracted single-atom-thick crystallites from bulk graphite in 2004 for the first time. This results earned them the Nobel Prize in physics 2010.
A group of researchers from Osaka University, the University of Tokyo, Kyoto University, and the National Institute for Materials Science precisely examined current-fluctuation ("shot noise") in the graphene p-n junction in the Quantum Hall (QH) regime and succeeded in observing electron partitioning taking place on the region along the p-n junction as current fluctuation.
In addition, this group also clarified that electron partitioning did not take place under the absence of the p-n junction even in the QH regime.
It is expected that this group's achievement will lead to the clarification of the electron partition process in the graphene p-n junction in the QH regime because of its spin freedom and valley freedom and the realization of electron interference devices using the graphene p-n junction in the QH regime.
Kensuke Kobayashi (Professor, Graduate School of Science, Osaka University) and Sadashige Matsuo (Assistant Professor, Graduate School of Engineering, The University of Tokyo), in cooperation with research groups led by Teruo Ono (Professor, Institute for Chemical Research, Kyoto University) and Kazuhito Tsukagoshi (Research Fellow, International Center for Materials Nanoarchitectonics, National Institute for Materials Science), produced graphene samples capable of forming p-n junctions by combining gate electrodes and performed precise measurements of current-fluctuation ("shot noise") in the graphene p-n junction in the QH regime in the strong magnetic fields and at low temperatures.
As shown by Figure 1, this group clarified that while shot noise took place in the graphene p-n junction in the QH regime, shot noise did not take place in the absence of the graphene p-n junction. This group also verified that the quantity of the observed shot noise was nearly consistent with theoretical predictions.
These results directly demonstrated for the first time in the world that electron partitioning took place in the p-n junction in the QH regime, and microscopic characteristics of electron partitioning taking place in the graphene p-n junction were quantitatively established for the first time.
This research was published in the electronic version of Nature Communications (UK) on September 4, 2015. Furthermore, results closely related to this group's research results were simultaneously published in the Nature Communications by a joint group of researchers from Nippon Telegraph and Telephone Corporation (NTT) and French research institutes. The latter research was performed totally independently from the former research, thus, it is noteworthy that the world's first research results were simultaneously announced from the two separate Japanese research teams.
Suggested Items
Altair Acquires Research in Flight, Forging a New Path for Aerodynamic Analysis
05/07/2024 | AltairAltair a global leader in computational intelligence, announced it has acquired Research in Flight, maker of FlightStream®, which provides computational fluid dynamics (CFD) software with a large footprint in the aerospace and defense sector and a growing presence in marine, energy, turbomachinery, and automotive applications.
Altair Acquires Research in Flight, Forging a New Path for Aerodynamic Analysis
05/03/2024 | AltairAltair a global leader in computational intelligence, announced it has acquired Research in Flight, maker of FlightStream®, which provides computational fluid dynamics (CFD) software with a large footprint in the aerospace and defense sector and a growing presence in marine, energy, turbomachinery, and automotive applications.
Intel Takes Next Step Toward Building Scalable Silicon-Based Quantum Processors
05/02/2024 | BUSINESS WIRENature published an Intel research paper, “Probing single electrons across 300-mm spin qubit wafers,” demonstrating state-of-the-art uniformity, fidelity and measurement statistics of spin qubits.
Argonne, Toyota Collaborate on Cutting-Edge Battery Recycling Process
05/01/2024 | BUSINESS WIREThe U.S. Department of Energy’s (DOE) Argonne National Laboratory has recently launched a collaboration with Toyota Motor North America that could reduce the nation’s reliance on foreign sources of battery materials.
Chinese Smartphone Market Maintains its Recovery Momentum at 6.5% Growth in 1Q24,
04/26/2024 | IDCAccording to preliminary data from the International Data Corporation (IDC) Worldwide Quarterly Mobile Phone Tracker, China smartphone shipments grew 6.5% year over year (YoY) to 69.3 million units in 1Q24.