Editing Mach–Zehnder interferometer (section)

{{Short description|Device to determine relative phase shift}}
[[File:Mach–Zehnder interferometer.gif|thumb|Light in Mach–Zehnder interferometer produces interference (wave-like behavior) even when being detected one photon at a time (particle-like behavior)]]
{{Quantum mechanics|cTopic=Experiments}}

The '''Mach–Zehnder interferometer''' is a device used to determine the relative [[Phase (waves)|phase shift]] variations between two [[collimated]] beams derived by splitting light from a single source. The [[interferometer]] has been used, among other things, to measure phase shifts between the two beams caused by a sample or a change in length of one of the paths. The apparatus is named after the physicists [[Ludwig Mach]] (the son of [[Ernst Mach]]) and [[Ludwig Zehnder]]; Zehnder's proposal in an 1891 article<ref>{{cite journal|last=Zehnder|first=Ludwig|title=Ein neuer Interferenzrefraktor|journal=Zeitschrift für Instrumentenkunde|date=1891|volume=11|pages=275&ndash;285|url=https://archive.org/details/zeitschriftfrin11gergoog}}</ref> was refined by Mach in an 1892 article.<ref>{{cite journal|last=Mach|first=Ludwig|title=Ueber einen Interferenzrefraktor|journal=Zeitschrift für Instrumentenkunde | volume = 12 | date = 1892 | pages = 89–93|url=https://archive.org/details/zeitschriftfrin14gergoog}}</ref> Mach–Zehnder [[interferometry]] has been demonstrated with electrons as well as with light.<ref>{{Cite journal|last1=Ji|first1=Yang|last2=Chung|first2=Yunchul|last3=Sprinzak|first3=D.|last4=Heiblum|first4=M.|last5=Mahalu|first5=D.|last6=Shtrikman|first6=Hadas|date=March 2003|title=An electronic Mach–Zehnder interferometer | url = http://www.nature.com/articles/nature01503|journal=[[Nature (journal)|Nature]] | language = en | volume = 422 | issue = 6930 | pages = 415–418 | doi = 10.1038/nature01503 | pmid = 12660779 | issn=0028-0836 | arxiv = cond-mat/0303553 |bibcode=2003Natur.422..415J|s2cid=4425291}}</ref> The versatility of the Mach–Zehnder configuration has led to its being used in a  range of research topics efforts especially in fundamental quantum mechanics.