Anomalous photon-assisted tunneling in graphene

Area of Science:

• Condensed Matter Physics
• Quantum Mechanics
• Optoelectronics

Background:

• Dirac electrons exhibit unique quantum phenomena in materials like graphene.
• Electron transmission through potential barriers is fundamental to understanding electronic devices.
• Photon-assisted transport can modify electron behavior in materials.

Purpose of the Study:

• To investigate the transmission of Dirac electrons through a potential barrier under circularly polarized light.
• To analyze the anomalous photon-assisted enhanced transmission and its underlying mechanisms.
• To explore the impact of various factors on perfect and photon-assisted transmission.

Main Methods:

• Theoretical investigation of Dirac electron transmission.
• Analysis of electron behavior in the presence of potential barriers and circularly polarized light.
• Modeling the effects of gapped dressed states, incident angles, photon-induced gaps, rough edges, and impurity scattering.

Main Results:

• Predicted and explained anomalous photon-assisted enhanced transmission.
• Demonstrated suppression of perfect transmission in gapped dressed states, with peak shifts at varying incident angles.
• Observed partial suppression of perfect transmission due to photon-induced gaps.
• Showed complete suppression of perfect transmission and reduced photon-assisted transmission range with rough edges or impurity scattering.

Conclusions:

• Circularly polarized light can anomalously enhance Dirac electron transmission.
• The perfect transmission of Dirac electrons is sensitive to material properties and external conditions.
• Factors such as gapped states, incident angle, and imperfections significantly influence electron transport, offering insights for controlling electronic properties.