Under certain biasing conditions, the intersubband energy separation in a quantum wire can match the optical phonon energy, thereby enhancing the scattering of charge carriers. We provide direct theoretical evidence that an anomalous negative differential transconductance (NDT) recently observed in an array of quantum wires at high temperatures is caused by resonant intersubband optical phonon scattering. Self-consistent 2D solutions of the Schrodinger and Poisson equations with a subsequent Monte Carlo analysis of intersubband scattering reveal a strong resonant polar optic phonon coupling between subbands at the gate bias indicated by the experimental data. The peak-to-valley ratio of the NDT exhibits a maximum near 170 K, thereby confirming the predictions of several theoretical investigations. The observation of resonant scattering is only possible because the quasi-1D form of Gauss's law shows an opposite trend to that for 2D systems in the dependence of the eigen energy spectrum on gate bias.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering
- Materials Chemistry