Proposed strategy to sort semiconducting nanotubes by radius and chirality

TL;DR

This paper introduces a method using a tunable laser and non-linear potential to sort semiconducting nanotubes by radius and chirality based on exciton behavior and polarization effects.

Contribution

It presents a novel strategy leveraging exciton polarization and disassociation dynamics to achieve nanotube sorting by physical properties.

Findings

Exciton binding energy drops to zero at certain conditions

Polarized excitons experience a net force towards electrodes

Sorting efficiency depends on exciton disassociation dynamics

Abstract

We propose a strategy that uses a tunable laser and an alternating non-linear potential to sort a suspension of assorted semiconducting nanotubes. Since, a polarized exciton is a dipole, the excited nanotubes will experience a net force and may then diffuse towards an electrode. The calculated exciton binding energy suddenly drops to zero and the force on the nanotube increases dramatically when the exciton disassociates as the nanotube moves towards the electrode. The quantum adiabatic theorem shows that excitons will be polarized for potential frequencies typical for experiments $\approx 10$ MHz.