Thermoelectric current in topological insulator nanowires with impurities

TL;DR

This study investigates how impurities and magnetic fields influence thermoelectric current sign reversal in topological insulator nanowires under temperature gradients, revealing impurity effects on current magnitude and reversal persistence.

Contribution

It provides new insights into impurity effects on thermoelectric current sign reversal in topological insulator nanowires under magnetic fields.

Findings

Impurities reduce the thermoelectric current magnitude.

Sign reversal persists at moderate impurity levels.

Magnetic impurities are more effective in diminishing the current.

Abstract

In this paper we consider charge current generated by maintaining a temperature difference over a nanowire at zero voltage bias. For topological insulator nanowires in a perpendicular magnetic field the current can change sign as the temperature of one end is increased. Here we study how this thermoelectric current sign reversal depends on magnetic field and how impurities affect the size of the thermoelectric current. We consider both scalar and magnetic impurities and show that their influence on the current are quite similar, although the magnetic impurities seem to be more effective in reducing the effect. For moderate impurity concentration the sign reversal persists.