A quantum point contact (QPC) is a narrow constriction between two wide electrically conducting regions, of a width comparable to the electronic wavelength (nano- to micrometer). Quantum point contacts were first reported in 1988 by a Dutch group (Van Wees et al.) and, independently, by a British group (Wharam et al.). They are based on earlier work by the British group which showed how split gates could be used to convert a two-dimensional electron gas into one-dimension, first in silicon (Dean and Pepper) and then in gallium arsenide (Thornton et al., Berggren et al.)
Read more about Quantum Point Contact: Fabrication, Properties, Applications
Famous quotes containing the words quantum, point and/or contact:
“A personality is an indefinite quantum of traits which is subject to constant flux, change, and growth from the birth of the individual in the world to his death. A character, on the other hand, is a fixed and definite quantum of traits which, though it may be interpreted with slight differences from age to age and actor to actor, is nevertheless in its essentials forever fixed.”
—Hubert C. Heffner (1901–1985)
“A point of view can be a dangerous luxury when substituted for insight and understanding.”
—Marshall McLuhan (1911–1980)
“My profession brought me in contact with various minds. Earnest, serious discussion on the condition of woman enlivened my business room; failures of banks, no dividends from railroads, defalcations of all kinds, public and private, widows and orphans and unmarried women beggared by the dishonesty, or the mismanagement of men, were fruitful sources of conversation; confidence in man as a protector was evidently losing ground, and women were beginning to see that they must protect themselves.”
—Harriot K. Hunt (1805–1875)