Related Experiment Video
Updated: May 18, 2026
15:47
Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots
Published on: November 1, 2013
Electrical control of interdot electron tunneling in a double InGaAs quantum-dot nanostructure
K Müller1, A Bechtold, C Ruppert
1Walter Schottky Institut and Physik-Department, Technische Universität München, Am Coulombwall 4, 85748 Garching, Germany.
Physical Review Letters
|September 26, 2012
Summary
We observed ultrafast electron tunneling between quantum dots using pump-probe spectroscopy. This tunneling, crucial for quantum computing, occurs via elastic and inelastic processes over a wide bandwidth.
Area of Science:
- Quantum physics
- Condensed matter physics
- Spectroscopy
Background:
- Electron tunneling is a fundamental quantum mechanical phenomenon.
- Quantum dots are semiconductor nanocrystals with tunable electronic properties.
- Understanding interdot electron transfer is key for developing quantum technologies.
Purpose of the Study:
- To directly monitor electron tunneling between spatially separated quantum dots.
- To investigate the role of Coulomb interactions and resonant tunneling processes.
- To measure electron and hole tunneling times separately.
Main Methods:
- Ultrafast pump-probe spectroscopy was employed.
- The relative energy of orbital states in quantum dots was tuned.
- Temporal evolution of pump-probe spectra was monitored.
Main Results:
- Coulomb interactions influenced the photogenerated charge carriers.
- Resonant tunneling was mediated by both elastic and inelastic processes.
- Ultrafast interdot tunneling (<5 ps) occurred over a wide bandwidth (∼8 meV).
Conclusions:
- Electron tunneling between quantum dots is directly observed and characterized.
- The study reveals the mechanisms and timescales of interdot electron transfer.
- Exciton-acoustic phonon coupling significantly influences the tunneling bandwidth.
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