Control of electron-electron interaction in graphene by proximity screenings

Area of Science:

• Condensed matter physics
• Materials science
• Quantum mechanics

Background:

• Electron-electron interactions are fundamental to condensed matter phenomena.
• Controlling interaction strength is key to understanding and manipulating quantum materials.
• Proximity to metals can screen electron interactions, offering a control mechanism.

Purpose of the Study:

• To investigate the effect of proximity screening on electron-electron interactions in graphene.
• To measure the electron-electron scattering length in graphene under controlled screening conditions.
• To explore the potential of metallic proximity for manipulating many-body phenomena in 2D systems.

Main Methods:

• Fabrication of devices with atomically-thin gate dielectrics and metallic gates.
• Measurement of electron-electron scattering length in graphene.
• Theoretical analysis of screening effects and comparison with experimental data.

Main Results:

• Observed qualitative deviations from standard electron-electron interaction behavior in graphene.
• Demonstrated that proximity screening effects become significant at few-nanometer dielectric thicknesses.
• Experimental findings align with theoretical predictions and measurements of electron viscosity and umklapp scattering.

Conclusions:

• Proximity screening by metals offers a viable method to control electron-electron interactions in graphene.
• The effect is pronounced at extremely small dielectric separations, enabling new experimental regimes.
• This work provides a roadmap for utilizing proximity effects in two-dimensional materials for advanced quantum applications.