English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Graphene is a nonmagnetic semimetal and cannot be directly used as electronicor spintronic devices. We demonstrate that graphene quantum dots (GQDs) canexhibit strong edge magnetism and tunable energy gaps due to the presence oflocalized edge states. By using large-scale first principle density functionaltheory (DFT) calculations and detailed analysis based on model Hamiltonians, wecan show that the zigzag edge states in GQDs become much stronger and morelocalized as the system size increases. The enhanced edge states induce strongelectron-electron interactions along the edges of GQDs, ultimately resulting ina magnetic phase transition from nonmagnetic to intra-edge ferromagnetic andinter-edge antiferromagnetic, when the diameter is larger than 4.5 nm. Ouranalysis shows that the inter-edge superexchange interaction ofantiferromagnetic states between two nearest-neighbor zigzag edges in GQDs ismuch stronger than that exists between two parallel zigzag edges in GQDs andgraphene nanoribbons. Furthermore, such strong and localized edge states alsoinduce GQDs semiconducting with tunable energy gaps, mainly controlled byadjusting the system size. Our results show that the quantum confinementeffect, inter-edge superexchange (antiferromagnetic), and intra-edge directexchange (ferromagnetic) interactions are crucial for the electronic andmagnetic properties of zigzag GQDs at the nanoscale.

Strong Edge Magnetism and Tunable Energy Gaps in Zigzag Graphene Quantum Dots with High Stability