Manipulation of electron orbitals in hard-wall InAs/InP nanowire quantum dots

TL;DR

This paper introduces a new method to manipulate electron orbitals in InAs/InP nanowire quantum dots using local gates, significantly improving control over energy levels and device temperature performance.

Contribution

The study demonstrates a novel gate-based technique to control electronic orbitals and energy spacing in nanowire quantum dots, enhancing their operational temperature range and electron control.

Findings

Enhanced energy spacing between quantum levels

Robust conductance modulation at liquid nitrogen temperature

Precise control of electron filling down to last carrier

Abstract

We present a novel technique for the manipulation of the energy spectrum of hard-wall InAs/InP nanowire quantum dots. By using two local gate electrodes, we induce a strong electric dipole moment on the dot and demonstrate the controlled modification of its electronic orbitals. Our approach allows us to dramatically enhance the single-particle energy spacing between the first two quantum levels in the dot and thus to increment the working temperature of our InAs/InP single-electron transistors. Our devices display a very robust modulation of the conductance even at liquid nitrogen temperature, while allowing an ultimate control of the electron filling down to the last free carrier. Potential further applications of the technique to time-resolved spin manipulation are also discussed.