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Photonic topological insulator
Physicsch: /* Background */
'''Photonic topological insulators''' are artificial electromagnetic materials that support topologically non-trivial, unidirectional states of light.<ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref>Photonic topological phases are classical electromagnetic wave analogies of electronic [[topological phase]]s studied in [[condensed matter physics]], and similar to their electronic counterparts, they, can provide robust unidirectional channels for light propagation. <ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref>
The field that studies these phases of light is referred to as '''topological photonics''', even though the working frequency of these ''electromagnetic'' topological insulators may fall in other parts of the electromagnetic spectrum such as the microwave range.<ref name="khanikaev" />
== History ==
Topological order in solid state systems has been studied in condensted matter physics since the discovery of [[quantum Hall effect|integer quantum Hall effect]]. But they attracted considerable interest from the physics community after the proposals for possible observation of symmetry-protected topological phases (or the so-called ''[[toplogical insulator]]s'') in [[graphene]]<ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref>, and experimental observation of a 2D topological insulator in CdTe/HgTe/CdTe quantum wells in 2007.<ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref><ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref>
In 2008, [[Haldane]] and Raghu proposed that unidirectional electromagnetic states analogous to (integer) quantum Hall states can be realized in nonreciprocal magnetic [[photonic crystal]]s. <ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref> This was followed by the proposals for analogous [[Quantum spin Hall effect|quantum spin Hall state]]s of electromagnetic waves that are now known as photonic topological insulators.<ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref><ref name="khanikaev">Liquid error: wrong number of arguments (given 1, expected 2)</ref>
== See also ==
* [[Symmetry-protected topological order]]
* [[Metamaterial]]
== References ==
[[Category:Photonics]]
[[Category:Electromagnetism]]
The field that studies these phases of light is referred to as '''topological photonics''', even though the working frequency of these ''electromagnetic'' topological insulators may fall in other parts of the electromagnetic spectrum such as the microwave range.<ref name="khanikaev" />
== History ==
Topological order in solid state systems has been studied in condensted matter physics since the discovery of [[quantum Hall effect|integer quantum Hall effect]]. But they attracted considerable interest from the physics community after the proposals for possible observation of symmetry-protected topological phases (or the so-called ''[[toplogical insulator]]s'') in [[graphene]]<ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref>, and experimental observation of a 2D topological insulator in CdTe/HgTe/CdTe quantum wells in 2007.<ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref><ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref>
In 2008, [[Haldane]] and Raghu proposed that unidirectional electromagnetic states analogous to (integer) quantum Hall states can be realized in nonreciprocal magnetic [[photonic crystal]]s. <ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref> This was followed by the proposals for analogous [[Quantum spin Hall effect|quantum spin Hall state]]s of electromagnetic waves that are now known as photonic topological insulators.<ref>Liquid error: wrong number of arguments (given 1, expected 2)</ref><ref name="khanikaev">Liquid error: wrong number of arguments (given 1, expected 2)</ref>
== See also ==
* [[Symmetry-protected topological order]]
* [[Metamaterial]]
== References ==
[[Category:Photonics]]
[[Category:Electromagnetism]]
October 05, 2019 at 04:02PM
