Editing Quantum well (section)

{{Short description|Concept in quantum mechanics}}
[[File:quantum well.svg|400px|thumb|Quantum well. Scheme of heterostructure of nanometric dimensions that gives rise to quantum effects. The shaded part with length ''L'' shows the region with constant (discrete) [[valence band]].<ref>{{Cite web|url=http://www.ir-nova.se/qwip/|title=Quantum Well Infrared Photon Detectors {{!}} IRnova|website=www.ir-nova.se|language=en-US|access-date=2018-09-04}}</ref>]]

A '''quantum well''' is a [[potential well]] with only discrete energy values.

The classic model used to demonstrate a quantum well is to confine particles, which were initially free to move in three dimensions, to two dimensions, by forcing them to occupy a planar region. The effects of [[quantum confinement]] take place when the quantum well thickness becomes comparable to the [[de Broglie wavelength]] of the carriers (generally [[electron]]s and [[electron hole|holes]]), leading to energy levels called "energy subbands", i.e., the carriers can only have discrete energy values.

The concept of quantum well was proposed in 1963 independently by [[Herbert Kroemer]] and by [[Zhores Alferov]] and R.F. Kazarinov.<ref name="kroemer">{{cite journal | last=Kroemer | first=H. | title=A proposed class of hetero-junction injection lasers | journal=Proceedings of the IEEE | publisher=Institute of Electrical and Electronics Engineers (IEEE) | volume=51 | issue=12 | year=1963 | issn=0018-9219 | doi=10.1109/proc.1963.2706 | pages=1782–1783}}</ref><ref name="alferov">Zh. I. Alferov and R.F. Kazarinov, Authors Certificate 28448 (U.S.S.R) 1963.</ref>