Origin of The Concept of Quantum Wells
In 1972, Charles H. Henry, a physicist and newly-appointed Head of the Semiconductor Electronics Research Department at Bell Laboratories, had a keen interest in the subject of integrated optics, the fabrication of optical circuits in which the light travels in waveguides.
In late 1972, while pondering the problems associated with waveguides, he had a sudden insight, a realization that a double heterostructure is a waveguide for electron waves, not just lightwaves. On further reflection, he saw that there is a complete analogy between the confinement of light by a slab waveguide and the confinement of electrons by the potential well that is formed from the difference in bandgaps in a double heterostructure.
Henry realized that there should be discrete modes (levels) in the potential well, and a simple estimate showed that if the active layer of the heterostructure is as thin as several tens of nanometres, the electron levels would be split apart by tens of milli-electron volts, which should be observable. This structure is now called a quantum well.
Henry then calculated how this quantization would alter the optical absorption edge of the semiconductor. His conclusion was that instead of the optical absorption increasing smoothly, the absorption edge of a thin heterostructure would appear as a series of steps.
In addition to Henry's contributions, the quantum well (or double-heterostructure laser, as it was originally known) was actually first proposed in 1963 by Herber Kroemer in Proceedings of the IEEE and simultaneously (in 1963) in the U.S.S.R by Zh. I. Alferov and R.F. Kazarinov. Alferov and Kroemer shared a Nobel Prize in 2000 for their work in semiconductor heterostructures.
Read more about this topic: Quantum Well Laser
Famous quotes containing the words origin of the, origin of, origin, concept, quantum and/or wells:
“The real, then, is that which, sooner or later, information and reasoning would finally result in, and which is therefore independent of the vagaries of me and you. Thus, the very origin of the conception of reality shows that this conception essentially involves the notion of a COMMUNITY, without definite limits, and capable of a definite increase of knowledge.”
—Charles Sanders Peirce (1839–1914)
“The real, then, is that which, sooner or later, information and reasoning would finally result in, and which is therefore independent of the vagaries of me and you. Thus, the very origin of the conception of reality shows that this conception essentially involves the notion of a COMMUNITY, without definite limits, and capable of a definite increase of knowledge.”
—Charles Sanders Peirce (1839–1914)
“High treason, when it is resistance to tyranny here below, has its origin in, and is first committed by, the power that makes and forever re-creates man.”
—Henry David Thoreau (1817–1862)
“I think that Richard Nixon will go down in history as a true folk hero, who struck a vital blow to the whole diseased concept of the revered image and gave the American virtue of irreverence and skepticism back to the people.”
—William Burroughs (b. 1914)
“But how is one to make a scientist understand that there is something unalterably deranged about differential calculus, quantum theory, or the obscene and so inanely liturgical ordeals of the precession of the equinoxes.”
—Antonin Artaud (1896–1948)
“Yes, that’s what I needed. Living flesh from humans for my experiments. What difference did it make if a few people had to die? Their flesh taught me how to manufacture arms, legs, faces that are human. I’ll make a crippled world whole again.”
—Robert Tusker, and Michael Curtiz. Wells (Preston Foster)