Large-scale mesoscopic transport in nanostructured graphene

Area of Science:

• Condensed matter physics
• Materials science
• Nanotechnology

Background:

• Electron localization is crucial for understanding transport properties in nanostructured materials.
• Mesoscopic transport phenomena in graphene exhibit complex behaviors influenced by dimensionality and disorder.

Purpose of the Study:

• To investigate strong electron localization in nanostructured antidot graphene.
• To characterize the mesoscopic transport and identify key energy gaps influencing electron scattering.

Main Methods:

• Exponential scaling of conductance with sample size.
• Temperature-dependent conductance measurements below 25 K.
• Analysis of transport properties including localization lengths and dephasing lengths.

Main Results:

• Demonstrated strong electron localization with localization lengths of 1.1, 2, and 3.4 μm.
• Observed a parallel conduction channel alongside 2D variable range hopping.
• Identified a Coulomb quasigap and a correlation quasigap around the Fermi level.
• Measured a dephasing length of 10 μm due to suppressed inelastic electron-electron scattering.

Conclusions:

• Nanostructured antidot graphene exhibits significant electron localization.
• The observed quasigaps play a critical role in controlling electron scattering mechanisms.
• The findings provide insights into quantum transport phenomena in mesoscopic systems.