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Quantum dots – not just for TVs

So, occasionally I run across articles which mention quantum dots; but more frequently I notice this technology promoted in higher quality flat screen displays and TVs. Photo-luminescent nanotechnology. This article (below) reminds me that the technology is critical in quantum information processing, e.g., quantum computing.

And as Wiki notes, modeling quantum dots showcases the interplay of quantum mechanical, semiclassical, and classical physics: “A variety of theoretical frameworks exist to model optical, electronic, and structural properties of quantum dots. These may be broadly divided into quantum mechanical, semiclassical, and classical.” > “Direct visualization of quantum dots reveals shape of quantum wave function” by University of California – Santa Cruz (Nov 24, 2020)

Bilayer graphene visualization
Visualization of quantum dots in bilayer graphene using scanning tunneling microscopy and spectroscopy reveals a three-fold symmetry [vs. circularly symmetric rings in monolayer graphene]. In this three-dimensional image, the peaks represent sites of high amplitude in the waveform of the trapped electrons. Credit: Zhehao Ge, Frederic Joucken, and Jairo Velasco Jr.

Trapping and controlling electrons in bilayer graphene quantum dots yields a promising platform for quantum information technologies. Researchers at UC Santa Cruz have now achieved the first direct visualization of quantum dots in bilayer graphene, revealing the shape of the quantum wave function of the trapped electrons.

Understanding the nature of the quantum dot wave function in bilayer graphene is important because this basic property determines several relevant features for quantum information processing, such as the electron energy spectrum, the interactions between electrons, and the coupling of electrons to their environment.

“The peaks represent sites of high amplitude in the wave function. Electrons have a dual wave-particle nature, and we are visualizing the wave properties of the electron in the quantum dot.”