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Compact Quantum Dots for Single-molecule Imaging
Published on: October 9, 2012
Counting statistics of single electron transport in a quantum dot
S Gustavsson1, R Leturcq, B Simovic
1Solid State Physics Laboratory, ETH Zürich, CH-8093 Zürich, Switzerland. simongus@phys.ethz.ch
Physical Review Letters
|April 12, 2006
Summary
We measured electron tunneling in semiconductor quantum dots to analyze current fluctuations. This technique reveals suppressed shot noise and distribution asymmetry, enabling sensitive measurements of low currents and noise.
Area of Science:
- Quantum physics
- Condensed matter physics
- Semiconductor devices
Background:
- Quantum dots (QDs) are crucial in nanoscale electronics.
- Understanding current fluctuations is key to device performance.
- Shot noise and distribution asymmetry provide insights into electron transport.
Purpose of the Study:
- To measure the full counting statistics of current fluctuations in a semiconductor quantum dot.
- To demonstrate a novel method for real-time detection of single electron tunneling.
- To experimentally show the suppression of noise and asymmetry in QD current.
Main Methods:
- Utilized real-time detection of single electron tunneling.
- Employed a quantum point contact as a sensitive detector.
- Measured the distribution function of current fluctuations directly.
Main Results:
- Successfully measured the full counting statistics of current fluctuations.
- Demonstrated experimental suppression of the second moment (shot noise).
- Showcased experimental suppression of the third moment (distribution asymmetry).
Conclusions:
- The developed method provides direct access to current fluctuation distributions.
- This technique enables the measurement of very low current and noise levels.
- The findings offer new possibilities for characterizing quantum electronic devices.
