Improving the ballistic AC conductivity through quantum resonance in branched nanowires

Abstract

Frequency-dependent electrical conductivity is studied by means of the Kubo-Greenwood formula and a real-space renormalization plus convolution method. An analytical solution of the alternating current (AC) conductivity is found for periodic chains. In this article, we report enhancements to this ballistic AC conductivity when periodically or quasiperiodically placed Fano-Anderson impurities are introduced to an otherwise periodic chain, which is connected to two semi-infinite periodic leads at its ends. Moreover, the temperature effects on these resonant AC conducting states are remarkably different in periodic and in quasiperiodic systems. Finally, such enhancement is further analysed in branched nanowires with a small cross section.

Keywords:

• electronic transport
• Kubo-Greenwood formula
• AC conductivity
• branched nanowires

Additional information

Funding

This work has been partially supported by CONACyT-131596, UNAM-DGAPA-PAPIIT IN113813 and IN113714. Computations were performed at Miztli of DGTIC, UNAM.