Iterambere ryakozwe mubushakashatsi bwibikorwa bya ultrafast ya Weil quasiparticles iyobowe nalaseri
Mu myaka ya vuba aha, ubushakashatsi bwibanze nubushakashatsi kuri topum ya topologiya hamwe nibikoresho bya topologiya byahindutse ingingo ishyushye mubijyanye na fiziki yibintu.Nkigitekerezo gishya cyo gutondekanya ibintu, gahunda ya topologiya, kimwe nuburinganire, nigitekerezo cyibanze muri fiziki yegeranye.Gusobanukirwa byimbitse kuri topologiya bifitanye isano nibibazo byibanze muri fiziki yibintu bifatika, nkuburyo bwibanze bwa elegitoroniki yaicyiciro cya kwant, kwant kwinzibacyuho no gushimishwa nibintu byinshi byimibilisitiya mubice bya kwant.Mubikoresho bya topologiya, guhuza hagati yinzego nyinshi zubwisanzure, nka electron, fonone na spin, bigira uruhare runini mugusobanukirwa no kugenzura ibintu bifatika.Ibyishimo byumucyo birashobora gukoreshwa mugutandukanya imikoranire itandukanye no gukoresha imiterere yibintu, kandi amakuru ajyanye nibintu byingenzi bifatika bifatika, inzibacyuho yimiterere, hamwe na leta nshya ya kwant irashobora kuboneka.Kugeza ubu, isano iri hagati yimyitwarire ya macroscopique yibikoresho bya topologiya itwarwa numurima wumucyo nuburyo bwa atome ya microscopique hamwe nibintu bya elegitoronike byabaye intego yubushakashatsi.
Imyitwarire ya fotoelectric yibikoresho bya topologiya bifitanye isano ya hafi na microscopique ya elegitoroniki.Kuri topologiya igice cya metero, ibyishimo byabatwara hafi yisangano ryumutwe byunvikana cyane kumikorere yibikorwa bya sisitemu.Ubushakashatsi bwibintu bidafite umurongo wa optique mubintu bya topologiya igice cya metero birashobora kudufasha kumva neza imiterere yumubiri yibihugu byishimye bya sisitemu, kandi biteganijwe ko izo ngaruka zishobora gukoreshwa mugukoraibikoresho byizanigishushanyo mbonera cyizuba, gitanga ibishoboka mubikorwa bizaza.Kurugero, mugice cya kabiri cya Weyl, gukuramo foton yumucyo uzengurutse uruziga bizatera kuzunguruka, kandi kugirango hubahirizwe kubungabunga imbaraga zinguni, umunezero wa electron kumpande zombi za Weyl uzagabanywa hamwe. icyerekezo cyo gukwirakwiza urumuri ruzengurutse urumuri, rwitwa itegeko ryo guhitamo chiral (Ishusho 1).
Ubushakashatsi bwibanze bwibintu bidafite umurongo wibikoresho bya topologiya mubisanzwe bifata uburyo bwo guhuza ibarwa ryimiterere yibintu bya leta hamwe nisesengura ryuzuye.Nyamara, ubu buryo bufite inenge zimwe: ntibubura amakuru nyayo-yingirakamaro yamakuru yabatwara bashimishijwe mumwanya wihuse hamwe nu mwanya nyawo, kandi ntishobora gushiraho igereranya ritaziguye nuburyo bwakemuwe bwo kugerageza ubushakashatsi.Guhuza hagati ya electron-fonone na foton-fonone ntibishobora gutekerezwa.Kandi ibi nibyingenzi kugirango inzibacyuho zimwe zibeho.Byongeye kandi, iri sesengura ryibanze rishingiye kubitekerezo bya perturbation ntishobora guhangana nuburyo bugaragara munsi yumucyo ukomeye.Ingero zishingiye ku gihe cyimikorere ya molekulari ikora (TDDFT-MD) kwigana ishingiye kumahame ya mbere irashobora gukemura ibibazo byavuzwe haruguru.
Vuba aha, iyobowe n’umushakashatsi Meng Sheng, umushakashatsi w’iposita Guan Mengxue n’umunyeshuri wa dogiteri Wang En wo mu itsinda rya SF10 rya Laboratoire ya Leta y’ibanze ya fiziki y’ubushakashatsi bw’ikigo cya fiziki cya siyansi y’ubushinwa / Ikigo cy’ubushakashatsi cy’ubushakashatsi cya Beijing. Fizika, ku bufatanye na Porofeseri Sun Jiatao wo mu Ishuri Rikuru ry’ikoranabuhanga rya Beijing, bakoresheje porogaramu ishimishije ya leta ya dinamike yigana TDAP.Harakurikiranwa ibimenyetso biranga ibisubizo bya kwastiparticle kuri ultrafast laser muburyo bwa kabiri bwa Weyl semi-metal WTe2.
Byerekanwe ko gushimisha guhitamo abatwara hafi ya Weyl point bigenwa na atomic orbital symmetry hamwe n amategeko yo gutoranya inzibacyuho, ibyo bikaba bitandukanye nuburyo busanzwe bwo gutoranya kuzenguruka kwishimisha chiral, kandi inzira yo kwishima irashobora kugenzurwa no guhindura icyerekezo cya polarisiyasi. y'umucyo utandukanijwe n'umucyo na fotone (FIG. 2).
Ibyishimo bya asimmetricike yabatwara bitera fotokoreri mubyerekezo bitandukanye mumwanya nyawo, bigira ingaruka kumyerekezo no guhuza kunyerera ya sisitemu.Kubera ko imiterere ya topologiya ya WTe2, nkumubare wamanota ya Weyl hamwe nurwego rwo gutandukana mumwanya wihuta, biterwa cyane nuburinganire bwa sisitemu (Ishusho 3), gushimisha asimmetrike yabatwara bizazana imyitwarire itandukanye ya Weyl quastiparticles mumwanya wihuta hamwe nimpinduka zijyanye nimiterere ya topologiya ya sisitemu.Rero, ubushakashatsi butanga igishushanyo mbonera cyerekana icyiciro cya fotopopologiya (Ishusho 4).
Ibisubizo byerekana ko chirality yibyishimo byabatwara hafi ya Weyl point igomba kwitabwaho, kandi imiterere ya atomic orbital yibikorwa byumuraba igomba gusesengurwa.Ingaruka zombi zirasa ariko uburyo biragaragara ko butandukanye, butanga urufatiro rwo gusobanura ubuke bwingingo za Weyl.Byongeye kandi, uburyo bwo kubara bwakoreshejwe muri ubu bushakashatsi burashobora gusobanukirwa byimazeyo imikoranire igoye hamwe nimyitwarire yingirakamaro kurwego rwa atome na elegitoronike mugihe cyihuta cyane, bikerekana uburyo bwabo bwa microphysical, kandi biteganijwe ko ari igikoresho gikomeye cyubushakashatsi buzaza kuri ibintu bitari byiza bya optique mubikoresho bya topologiya.
Ibisubizo biri mu kinyamakuru Itumanaho rya Kamere.Ibikorwa byubushakashatsi bishyigikiwe na gahunda yingenzi y’ubushakashatsi n’iterambere ry’igihugu, Fondasiyo y’igihugu y’ubumenyi bw’ibinyabuzima n’umushinga w’icyitegererezo (Icyiciro B) cy’ishuri ry’ubumenyi ry’Ubushinwa.
FIG.1.a.Ihitamo rya chirality kuri point ya Weyl hamwe nikimenyetso cyiza cya chirality (χ = + 1) munsi yumucyo uzengurutse uruziga;Ibyishimo byatoranijwe kubera guhuza atomike ya orbital kuri Weyl point ya b.χ = + 1 kumurongo wumucyo
FIG.2. Igishushanyo mbonera cya atome ya a, Td-WTe2;b.Imiterere ya bande hafi yubuso bwa Fermi;.d.Kongera imbaraga za bande kumurongo wa Gamma-X
FIG.3.ab.C. Kugereranya hagati yo kwigana no kureba ubushakashatsi;de: Ubwihindurize bwa Symmetry ya sisitemu n'umwanya, umubare n'urwego rwo gutandukanya ingingo ebyiri zegeranye Weyl mu ndege ya kz = 0
FIG.4. Inzibacyuho ya Photopopologique muri Td-WTe2 kumashanyarazi ya fotone yumucyo (?) Ω) hamwe nicyerekezo cya polarisiyasi (θ) igishushanyo cyicyiciro
Igihe cyo kohereza: Nzeri-25-2023