Khác biệt giữa bản sửa đổi của “Vật lý vật chất ngưng tụ”

 

==Thực nghiệm==

 

===Tán xạ===

Several condensed matter experiments involve scattering of an experimental probe, such as [[X-ray]], optical [[photon]]s, [[neutron]]s, etc., on constituents of a material. The choice of scattering probe depends on the observation energy scale of interest.<ref name=chaikin-lubensky>{{cite book|last=Chaikin|first=P. M.|last2=Lubensky|first2=T. C.|title=Principles of condensed matter physics|year=1995|publisher=Cambridge University Press|isbn=0-521-43224-3}}</ref> [[Visible light]] has energy on the scale of 1 [[electron volt|eV]] and is used as a scattering probe to measure variations in material properties such as [[dielectric constant]] and [[refractive index]]. X-rays have energies of the order of 10 [[electron volt|keV]] and hence are able to probe atomic length scales, and are used to measure variations in electron charge density. [[Neutron]]s can also probe atomic length scales and are used to study scattering off nuclei and electron [[Spin (physics)|spins]] and magnetization (as neutrons themselves have spin but no charge).<ref name=chaikin-lubensky/> Coulomb and [[Mott scattering]] measurements can be made by using electron beams as scattering probes,<ref>{{cite book|last=Riseborough|first=Peter S.|title=Condensed Matter Physics I|year=2002|url=http://www.scribd.com/doc/74216869/179/Electron-Scattering-Experiments}}</ref> and similarly, [[positron]] annihilation can be used as an indirect measurement of local electron density.<ref name=siegel-1980>{{cite journal|last=Siegel|first=R. W.|title=Positron Annihilation Spectroscopy|journal=Annual Review of Materials Science|year=1980|volume=10|pages=393–425|doi=10.1146/annurev.ms.10.080180.002141|bibcode = 1980AnRMS..10..393S }}</ref> [[Laser spectroscopy]] is used as a tool for studying phenomena with energy in the range of [[visible light]], for example, to study [[non-linear optics]] and [[forbidden transition]]s in media.<ref name=nap-cmp />