Harmonic Oscillator Wave Functions of a Self-Assembled InAs Quantum Dot Measured by Scanning Tunneling Microscopy

• Published in: Nano letters Vol. 13; no. 8; pp. 3571 - 3575
• Main Authors: Teichmann, Karen, Wenderoth, Martin, Prüser, Henning, Pierz, Klaus, Schumacher, Hans W, Ulbrich, Rainer G
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 14.08.2013
• Subjects: Applied sciences; Cross sections; Cross-disciplinary physics: materials science; rheology; Diodes; Electronics; Exact sciences and technology; Harmonic oscillators; Indium arsenides; Materials science; Methods of nanofabrication; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Oscillators; Physics; Quantum dots; Resonant tunneling; Scanning tunneling microscopy; Self-assembly; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Wave functions; Self-assembled quantum dots; III−V semiconductor; harmonic oscillator; STS; STM; Aluminium arsenides; Resonant tunneling diodes; Energy levels; Bound state; Quantum dots; Tunnel effect; Indium arsenides; III-V compound; Harmonic function; Scanning tunneling microscopy; Self-assembly; Wave functions; Scanning tunneling spectroscopy; Effective mass; Nanostructured materials; Spatial resolution; III-V semiconductors
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl401217q

InAs quantum dots embedded in an AlAs matrix inside a double barrier resonant tunneling diode are investigated by cross-sectional scanning tunneling spectroscopy. The wave functions of the bound quantum dot states are spatially and energetically resolved. These bound states are known to be responsible for resonant tunneling phenomena in such quantum dot diodes. The wave functions reveal a textbook-like one-dimensional harmonic oscillator behavior showing up to five equidistant energy levels of 80 meV spacing. The derived effective oscillator mass of m* = 0.24m 0 is 1 order of magnitude higher than the effective electron mass of bulk InAs that we attribute to the influence of the surrounding AlAs matrix. This underlines the importance of the matrix material for tailored QD devices with well-defined properties.