History
The integer quantization of the Hall conductance was originally predicted by Ando, Matsumoto, and Uemura in 1975, on the basis of an approximate calculation which they themselves did not believe to be true. Several workers subsequently observed the effect in experiments carried out on the inversion layer of MOSFETs. It was only in 1980 that Klaus von Klitzing, working with samples developed by Michael Pepper and Gerhard Dorda, made the unexpected discovery that the Hall conductivity was exactly quantized. For this finding, von Klitzing was awarded the 1985 Nobel Prize in Physics. The link between exact quantization and gauge invariance was subsequently found by Robert Laughlin. Most integer quantum Hall experiments are now performed on gallium arsenide heterostructures, although many other semiconductor materials can be used. In 2007, the integer quantum Hall effect was reported in graphene at temperatures as high as room temperature, and in the oxide ZnO-MgxZn1-xO.
Read more about this topic: Quantum Hall Effect
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“I am ashamed to see what a shallow village tale our so-called History is. How many times must we say Rome, and Paris, and Constantinople! What does Rome know of rat and lizard? What are Olympiads and Consulates to these neighboring systems of being? Nay, what food or experience or succor have they for the Esquimaux seal-hunter, or the Kanaka in his canoe, for the fisherman, the stevedore, the porter?”
—Ralph Waldo Emerson (1803–1882)
“The history of mankind interests us only as it exhibits a steady gain of truth and right, in the incessant conflict which it records between the material and the moral nature.”
—Ralph Waldo Emerson (1803–1882)
“Universal history is the history of a few metaphors.”
—Jorge Luis Borges (1899–1986)