Flat-Band AC Transport in Nanowires

Area of Science:

• Condensed matter physics
• Materials science
• Nanotechnology

Background:

• Flat electronic bands exhibit zero group velocity and null charge mobility.
• Localized states in nanowires are predicted when specific neighbor hopping integral relationships are met, achievable experimentally under pressure.
• Understanding AC transport in such systems is crucial for novel electronic applications.

Purpose of the Study:

• Investigate alternating current (AC) conductivity in nanowires with nearly flat electronic bands.
• Analyze the influence of first, second, and third neighbor hopping integrals on AC transport.
• Explore the behavior of charge carriers within these localized states under an external electric field.

Main Methods:

• Developed a novel independent channel method for the Kubo-Greenwood formula.
• Incorporated hopping integrals up to the third neighbor.
• Simulated AC conductivity in nanowire systems with nearly flat bands.

Main Results:

• Observed a large AC conductivity in the studied nanowires.
• Demonstrated that AC conductivity is sensitive to the boundary conditions of the measurement.
• Showcased resonant behavior of charge carriers oscillating around localized positions due to the external electric field.

Conclusions:

• The independent channel method provides a robust framework for studying AC transport in systems with localized states.
• Nanowires with nearly flat bands exhibit significant AC conductivity, highlighting their potential for electronic devices.
• The resonant oscillation of charge carriers offers new avenues for manipulating electronic transport at the nanoscale.