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Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection
Published on: October 13, 2017
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Terahertz intersublevel transitions in single self-assembled InAs quantum dots with variable electron numbers
Ya Zhang1, Kenji Shibata, Naomi Nagai
1Center for Photonics Electronics Convergence, Institute of Industrial Science and ‡Institute for Nano Quantum Information Electronics, University of Tokyo , 4-6-1 Komaba, Meguro-ku, Tokyo 153-8505, Japan.
Nano Letters
|January 13, 2015
Summary
We developed terahertz spectroscopy for nanometer systems using metal nanogap electrodes. This technique successfully measured quantum dot spectra, revealing distinct photocurrent behaviors based on electron configuration.
Area of Science:
- Condensed Matter Physics
- Nanotechnology
- Quantum Optics
Background:
- Terahertz (THz) spectroscopy is crucial for characterizing nanoscale systems.
- Previous methods faced challenges in achieving high signal-to-noise ratios for individual quantum dots.
Purpose of the Study:
- To develop a novel method for THz spectroscopy on nanometer-scale systems.
- To investigate the intersublevel transition spectra of individual self-assembled Indium Arsenide (InAs) quantum dots (QDs).
Main Methods:
- Utilized metal nanogap electrodes to create a single-electron transistor (SET) geometry.
- Employed the SET with QDs as a THz detector for high signal/noise ratio measurements.
- Analyzed photocurrent distribution relative to Coulomb diamonds.
Main Results:
- Successfully measured intersublevel transition spectra of single InAs QDs.
- Observed distinct photocurrent generation mechanisms dependent on electron shell occupancy.
- Identified simple p → d transition spectra when the p shell was fully occupied.
- Detected complex spectral behavior attributed to electron configuration fluctuations when the p shell was half-filled.
Conclusions:
- The proposed method enables sensitive THz spectroscopy of nanoscale systems.
- Electron configuration fluctuations significantly impact photocurrent spectra in quantum dots.
- This technique provides insights into the electronic properties of individual quantum dots.
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