Injection of a single electron from static to moving quantum dots

Area of Science:

• Quantum physics
• Condensed matter physics
• Nanotechnology

Background:

• Quantum dots are semiconductor nanostructures with tunable electronic properties.
• Surface acoustic waves (SAWs) can create and manipulate dynamic quantum dots.
• Controlling single-electron transfer between quantum dots is fundamental for quantum technologies.

Purpose of the Study:

• To elucidate the mechanism of single-electron injection from a static quantum dot into a moving quantum dot.
• To identify the key parameters governing the electron transfer efficiency.
• To determine the optimal conditions for efficient and potentially adiabatic electron transfer.

Main Methods:

• Fabrication of a long depleted channel with integrated static and dynamic quantum dots.
• Generation of moving quantum dots using surface acoustic waves (SAWs).
• Characterization of the electron injection process by analyzing its dependence on SAW amplitude and potential gradients.

Main Results:

• The electron injection process follows an activation law with a distinct threshold.
• The injection threshold is sensitive to both SAW amplitude and the quantum dot-channel potential gradient.
• A regime of unity probability and potentially adiabatic transfer was achieved by increasing SAW modulation amplitude.

Conclusions:

• The study identifies critical parameters for efficient single-electron transfer between quantum dots.
• Achieving high-fidelity transfer is feasible by optimizing SAW modulation and potential landscape.
• The findings provide essential insights for utilizing moving quantum dots in quantum information protocols.