Hatewe intambwe mu bushakashatsi ku mikorere yihuse ya Weil quasiparticles igenzurwa naimirasire ya laser
Mu myaka ya vuba aha, ubushakashatsi bushingiye ku nyigisho no ku bushakashatsi ku miterere ya quantum mu isanzure n'ibikoresho bya quantum mu isanzure bwabaye ingingo ikomeye mu bijyanye na fiziki y'ibintu bivanze. Nk'igitekerezo gishya cyo gushyira ibintu mu byiciro, gahunda y'ibintu bivanze, kimwe n'uburinganire, ni igitekerezo cy'ibanze muri fiziki y'ibintu bivanze. Gusobanukirwa byimbitse topology bifitanye isano n'ibibazo by'ibanze muri fiziki y'ibintu bivanze, nk'imiterere y'ibanze ya elegitoronikiibyiciro bya kwantumu, impinduka za phase ya quantum no gukurura ibintu byinshi bidakora mu byiciro bya quantum. Mu bikoresho bya topological, guhuza hagati y’urwego rwinshi rw’ubwisanzure, nka electrons, phonons na spin, bigira uruhare rukomeye mu gusobanukirwa no kugenzura imiterere y’ibintu. Gukurura urumuri bishobora gukoreshwa mu gutandukanya imikoranire itandukanye no guhindura imiterere y’ibintu, kandi amakuru yerekeye imiterere y’ibanze y’ibintu, impinduka z’imiterere y’imiterere, n’imiterere mishya ya quantum ashobora kuboneka. Kuri ubu, isano iri hagati y’imyitwarire ya macroscopic y’ibikoresho bya topological bitwarwa n’urumuri n’imiterere ya atome ya microscopic n’imiterere ya elegitoroniki yabaye intego y’ubushakashatsi.
Imyitwarire y’ibikoresho bya topological mu gusubiza amashanyarazi ifitanye isano rya bugufi n’imiterere yabyo ya elegitoroniki ntoya. Ku byuma bya topological, gushyuha kwa carrier hafi y’aho ihuriro ry’imirongo rihurira birakomeye ku miterere y’imikorere y’imiraba y’urusobe rw’amashanyarazi. Inyigo y’ibintu bitagaragara mu byuma bya topological bishobora kudufasha gusobanukirwa neza imiterere y’imiterere y’urusobe rw’amashanyarazi, kandi byitezwe ko izi ngaruka zishobora gukoreshwa mu gukoraibikoresho by'urumurin'igishushanyo mbonera cy'uturemangingo tw'izuba, bigatanga uburyo bufatika bwo gukoresha mu gihe kizaza. Urugero, muri Weyl semi-metal, kwinjiza fotoni y'urumuri rufite uruziga bizatuma urumuri ruzunguruka, kandi kugira ngo ruhuze no kubungabunga umuvuduko w'inguni, electron excitation ku mpande zombi za Weyl cone izakwirakwizwa mu buryo bungana mu cyerekezo cy'urumuri rufite uruziga, ari byo byitwa chiral selection rule (Ishusho ya 1).
Inyigo y’inyigo ku bintu bitagaragara mu buryo bw’izuba (nonlinear optical phenomenals) by’ibikoresho bya topological ubusanzwe ikoresha uburyo bwo guhuza imibare y’imiterere y’ubutaka n’isesengura ry’ubusumbane. Ariko, ubu buryo bufite inenge zimwe na zimwe: budafite amakuru ajyanye n’igihe nyacyo y’ibintu bishyushye mu mwanya w’ingufu n’umwanya nyawo, kandi ntibushobora kugaragaza igereranya ritaziguye n’uburyo bwo gupima bwakozwe mu gihe. Guhuza electron-phonens na foton-phonens ntibishobora kwitabwaho. Kandi ibi ni ingenzi kugira ngo habeho impinduka zimwe na zimwe mu byiciro. Byongeye kandi, ubu buryo bw’inyigo bushingiye ku nyigisho y’ihungabana ntibushobora guhangana n’imikorere y’umubiri munsi y’urumuri rukomeye. Inyigo y’impinduka mu mikorere y’ingufu za molekile (TDDFT-MD) ishingiye ku mahame ya mbere ishobora gukemura ibibazo byavuzwe haruguru.
Vuba aha, bayobowe n'umushakashatsi Meng Sheng, umushakashatsi wa postdoctoral Guan Mengxue n'umunyeshuri wa doctorat Wang En wo muri SF10 Group of the State Key Laboratory of Surface Physics of the Institute of Physics of the Chinese Academy of Sciences/Beijing National Research Center for Concentrated Matter Physics, bafatanyije na Porofeseri Sun Jiatao wo muri Beijing Institute of Technology, bakoresheje porogaramu ya TDAP yo kwiyitirira excited state dynamics simulation. Ibimenyetso by'uburyo quastiparticle excitation ikora kuri ultrafast laser muri Weyl semi-metal WTe2 birasuzumwa.
Byagaragaye ko uburyo bwo gukurura ibintu mu buryo butoranijwe hafi y’aho Weyl iherereye bugenwa n’itegeko ryo guhitamo ibintu mu buryo busanzwe no guhitamo ibintu mu buryo bunyuranyije n’uburyo ibintu bigenda bihinduka, bitandukanye n’itegeko risanzwe ryo guhitamo ibintu mu buryo buhindagurika mu buryo bufata intera, kandi inzira yabyo ishobora kugenzurwa no guhindura icyerekezo cya polarization y’urumuri rwa polarized linearly na photon energy (ISHUSHO YA 2).
Gushyushya kw'ibinyabiziga bidafite aho bihuriye bitera imiyoboro y'amashanyarazi mu byerekezo bitandukanye mu kirere nyacyo, ibyo bigira ingaruka ku cyerekezo no ku busumbane bw'ihindagurika ry'urwego rw'isi. Kubera ko imiterere y'ubutaka ya WTe2, nk'umubare w'ingingo za Weyl n'urwego rwo gutandukana mu mwanya w'umuvuduko, bishingiye cyane ku busumbane bw'iyi sisitemu (Ishusho ya 3), gushyushya kw'ibinyabiziga bidafite aho bihuriye bizazana imyitwarire itandukanye ya Weyl quastiparticles mu mwanya w'umuvuduko n'impinduka zijyanye n'imiterere y'ubutaka bw'iyi sisitemu. Bityo, ubushakashatsi butanga ishusho isobanutse y'impinduka z'urwego rw'ubusumbane (Ishusho ya 4).
Ibisubizo bigaragaza ko imiterere y’uruhererekane rw’ibintu bitwara hafi y’aho Weyl iherereye igomba kwitabwaho, kandi imiterere y’imikorere y’umuraba mu buryo bwa atome irasa ariko uburyo bwo kuyikora buratandukanye, ibyo bikaba bitanga ishingiro ry’inyigisho mu gusobanura imiterere y’ingingo za Weyl. Byongeye kandi, uburyo bwo kubara bwakoreshejwe muri ubu bushakashatsi bushobora gusobanukirwa byimbitse imikoranire ikomeye n’imyitwarire ihindagurika ku rwego rwa atome na elegitoroniki mu gihe cyihuse cyane, bukagaragaza uburyo bwazo bwa microphysical, kandi byitezwe ko buzaba igikoresho gikomeye cy’ubushakashatsi bw’ejo hazaza ku bintu bitagaragara mu buryo bw’amajwi mu bikoresho bya topological.
Ibisubizo biri mu kinyamakuru Nature Communications. Ubu bushakashatsi bushyigikiwe na Gahunda y'Igihugu y'Ubushakashatsi n'Iterambere ry'Ingenzi, Ikigo cy'Igihugu cy'Ubumenyi bw'Inyamaswa n'Umushinga w'Igerageza ry'Ingamba (Icyiciro cya B) cy'Ishuri Rikuru ry'Ubumenyi ry'Abashinwa.
ISHUSHO YA 1.a. Itegeko ryo guhitamo imiterere y'urumuri ku ngingo za Weyl zifite ikimenyetso cya imiterere y'urumuri (χ=+1) munsi y'urumuri rwazungurutse; Gushishikaza gutoranya bitewe n'uburinganire bwa atome ku gice cya Weyl cya b. χ=+1 mu rumuri rwazungurutse ruri kuri interineti
ISHUSHO YA 2. Ishusho y'imiterere ya atomu ya a, Td-WTe2; b. Imiterere y'umugozi hafi y'ubuso bwa Fermi; (c) Imiterere y'umugozi n'uruhare rw'imirongo ya atomu ikwirakwijwe ku mirongo miremire ingana mu gace ka Brillouin, imyambi (1) na (2) zigaragaza gushyuha hafi cyangwa kure y'ingingo za Weyl, uko bikurikirana; d. Kongera imiterere y'umugozi ku cyerekezo cya Gamma-X
ISHUSHO YA 3.ab: Inzira y'uruhererekane rw'icyerekezo cy'urumuri rwa polarized light linearly polarized ku murongo wa A-axis na B-axis wa kristale, hamwe n'uburyo bwo kugenda bujyanye nabyo biragaragazwa; C. Igereranya hagati yo kwigana inyigisho n'igerageza; de: Ihindagurika ry'uburyo bwo guhuza ibintu n'umwanya, umubare n'urwego rwo gutandukana kw'ingingo ebyiri zegereye za Weyl mu ndege ya kz=0
ISHUSHO YA 4. Impinduka mu cyiciro cya fototopolojia muri Td-WTe2 ku ngufu za fotoni y'urumuri rwa polarized linearly (?) ω) n'icyerekezo cya polarization (θ) bishingiye ku gipimo
Igihe cyo kohereza ubutumwa: 25 Nzeri 2023