(In,Ga)As gated-vertical quantum dot with an Al2O3 insulator

TL;DR

This paper reports the fabrication and low-temperature electrical characterization of a gated-vertical (In,Ga)As quantum dot with an Al2O3 insulator, demonstrating controlled electron occupancy and Coulomb blockade effects.

Contribution

It introduces a novel gated-vertical quantum dot structure with an Al2O3 insulator fabricated via atomic layer deposition, enabling precise electron control.

Findings

Clear Coulomb diamonds observed at 1.1K

Electron number in the quantum dot controlled from 0 to ~130

Successful integration of Al2O3 insulator for gate control

Abstract

We fabricated a gated-vertical (In,Ga)As quantum dot with an Al2O3 gate insulator deposited using atomic layer deposition and investigated its electrical transport properties at low temperatures. The gate voltage dependence of the dI/dV-V characteristics shows clear Coulomb diamonds at 1.1K. The metal-insulator gate structure allowed us to control the number of electrons in the quantum dot from 0 to a large number estimated to be about 130.