Electronic and transport properties in circular graphene structures with a pentagonal disclination

Area of Science:

• Condensed Matter Physics
• Materials Science
• Nanotechnology

Background:

• Graphene quantum dots exhibit unique electronic properties.
• Defects in graphene structures can significantly alter their behavior.
• Understanding localized states is crucial for quantum device applications.

Purpose of the Study:

• To investigate the electronic and transport properties of circular graphene quantum dots containing a pentagonal defect.
• To analyze the impact of the pentagonal defect on energy states and electron transport.

Main Methods:

• Utilized a tight-binding model for electronic structure calculations.
• Determined total and local density of states.
• Calculated transmission function and participation number.

Main Results:

• The pentagonal defect primarily affects electronic states near zero energy, characteristic of graphene edge states.
• Observed quasi-bound states generated by the defect and localized edge states due to circular boundaries and the defect.
• Calculated participation number confirmed changes in quasi-bound states and new transmission function peaks.

Conclusions:

• Pentagonal defects in circular graphene quantum dots induce localized electronic states.
• These defects create quasi-bound and edge states, influencing transport properties.
• The findings provide insights into defect engineering for graphene-based nanodevices.