Controlling Electrons in Graphene Opens a New Path to Potential Electronic Devices
April 21, 2017 | Department of Energy, Office of ScienceEstimated reading time: 1 minute
For the first time, scientists created a tunable artificial atom in graphene. They demonstrated that a vacancy in graphene can be charged in a controllable way such that electrons can be localized to mimic the electron orbitals of an artificial atom. Importantly, the trapping mechanism is reversible (turned on and off) and the energy levels can be tuned.
Starting with a missing atom, referred to as a vacancy (top left), and applying an electric charge that attracts electrons to the region, the electrons are confined into “orbitals” to create an “artificial atom” (lower right). The images are electron concentration maps obtained with scanning tunneling spectroscopy that visualize the vacancy, and then the electron orbitals (in red) of an artificial atom created in graphene. R1, R1’ and R2 show the orbitals in order of increasing energy.
The results from this research demonstrate a viable, controllable, and reversible technique to confine electrons in graphene. The energy states of the electrons are “tunable.” This tunability opens new avenues of research into the unique physics electron behavior in graphene. Further, it provides a methodology that could facilitate the use of graphene-based devices for future electronics, communications, and sensors.
Graphene’s remarkable electronic properties have fueled the vision of developing graphene-based devices to enable lighter, faster and smarter electronics and advanced computing applications. But progress towards this goal has been slowed by the inability to confine its charge carriers with applied voltage. A team led by researchers from Rutgers University developed a technique to stably host and controllably modify localized charge states in graphene. The researchers created vacancies (missing carbon atoms) in the graphene lattice, by bombarding the sample with charged helium atoms (He+ ions). They demonstrated that it is possible to deposit a positive charge at the vacancy site and to charge it gradually by applying voltage pulses with a scanning tunneling microscope tip. As the charge on the vacancy increases, its interaction with the conduction electrons in graphene undergoes a transition. The interaction turns into a regime where the electrons can be trapped into quasi-bound energy states that resemble an artificial atom. The team further showed that the quasi-bound states at the vacancy site are tunable with application of an external electric field. The trapping mechanism can be turned on and off, providing a new paradigm to control and guide electrons in graphene.
Suggested Items
I-Connect007 Editor’s Choice: Five Must-Reads for the Week
05/10/2024 | Marcy LaRont, PCB007 MagazineSpring is a renewal each year as dormant flora bloom, and baby ducklings and geese are ever present in local bodies of water. Even though it is beginning to get hot, I love this time of year in Arizona, with the sun waking me around 5 a.m. It fills me with an energy that I often lose in the dark winter months. Wherever you find yourself in the world, I hope you are enjoying Spring and that you are filled with energy and enthusiasm for all the great work part of our daily lives in this industry.
Future Innovators Challenged by UK Robotics Leaders to Design Nuclear Fission and Fusion Decommissioning Robots
05/09/2024 | RAICoStudents in West Cumbria have been tasked by the Robotics and AI Collaboration (RAICo) and the Industrial Solutions Hub (iSH) to design and build robots which will be showcased at a major robotics and artificial intelligence (RAI) industry event.
Dragonfly Energy Announces Breakthrough in Lithium Battery Production: Eliminating Harmful 'Forever Chemicals'
05/09/2024 | Globe NewswireDragonfly Energy Holdings Corp., an industry leader in green energy storage, has made a significant breakthrough in battery manufacturing with the successful production of PFAS-free electrodes in lithium battery cells.
SCHMID Group Closes Business Combination, Begins Trading on NASDAQ
05/02/2024 | SCHMID GroupGebr. SCHMID GmbH, a global solutions provider for the high-tech electronic, photovoltaics, glass, and energy systems industries, and Pegasus Digital Mobility Acquisition Corp. announced the completion of their business combination.
Flex Receives Ericsson 2023 Supplier Sustainability Award
04/30/2024 | FlexEricsson recently awarded Flex with its 2023 Supplier Sustainability Award — the second time since 2021. The award recognizes the extended supply chain benefits from sustainable manufacturing operations in the Flex facility in Tczew, Poland, that runs on 100 percent renewable energy.