Ua holomua ka noiʻi ʻana i ka neʻe wikiwiki loa o nā quasiparticles Weil i kāohi ʻia e nā lasers.

Ua holomua ka noiʻi ʻana i ka neʻe wikiwiki loa o nā quasiparticles Weil i kāohi ʻia enā lasers

I nā makahiki i hala iho nei, ua lilo ka noiʻi kumumanaʻo a me ka hoʻokolohua ma nā kūlana quantum topological a me nā mea quantum topological i kumuhana wela ma ke kahua o ka physics condensed matter. Ma ke ʻano he manaʻo hou o ka hoʻokaʻawale ʻana i nā mea, ʻo ke kauoha topological, e like me ka symmetry, he manaʻo nui ia i ka physics condensed matter. ʻO ka hoʻomaopopo hohonu ʻana i ka topology e pili ana i nā pilikia kumu i ka physics condensed matter, e like me ke ʻano uila kumu onā pae quantum, nā hoʻololi pae quantum a me ka hoʻonāukiuki ʻana o nā mea he nui i hoʻopaʻa ʻia i nā pae quantum. I nā mea topological, ʻo ka hoʻopili ʻana ma waena o nā kekelē he nui o ke kūʻokoʻa, e like me nā electrons, phonons a me ka spin, e pāʻani i kahi kuleana koʻikoʻi i ka hoʻomaopopo ʻana a me ka hoʻoponopono ʻana i nā waiwai o nā mea. Hiki ke hoʻohana ʻia ka hoʻonāukiuki māmā e hoʻokaʻawale ma waena o nā pilina like ʻole a hoʻoponopono i ke kūlana o ka mea, a hiki ke loaʻa ka ʻike e pili ana i nā waiwai kino kumu o ka mea, nā hoʻololi pae hoʻonohonoho, a me nā kūlana quantum hou. I kēia manawa, ua lilo ka pilina ma waena o ke ʻano macroscopic o nā mea topological i hoʻokele ʻia e ke kahua māmā a me ko lākou ʻano atomic microscopic a me nā waiwai uila i pahuhopu noiʻi.

ʻO ke ʻano pane photoelectric o nā mea topological e pili pono ana i kona ʻano uila microscopic. No nā semi-metala topological, ʻo ka hoʻonāukiuki lawe kokoke i ke kihi band he mea koʻikoʻi loa ia i nā ʻano hana nalu o ka ʻōnaehana. ʻO ke aʻo ʻana i nā hanana optical nonlinear i nā semi-metala topological hiki ke kōkua iā mākou e hoʻomaopopo maikaʻi i nā waiwai kino o nā kūlana hoʻonāukiuki o ka ʻōnaehana, a manaʻo ʻia e hiki ke hoʻohana ʻia kēia mau hopena i ka hana ʻana onā mea hana makaa me ka hoʻolālā ʻana o nā cell solar, e hāʻawi ana i nā noi kūpono i ka wā e hiki mai ana. No ka laʻana, i loko o kahi semi-metal Weyl, ʻo ka omo ʻana i kahi photon o ke kukui polarized circular e hoʻohuli i ka wili, a i mea e hoʻokō ai i ka mālama ʻana o ka momentum angular, e hoʻolaha like ʻole ʻia ka hoʻonāukiuki electron ma nā ʻaoʻao ʻelua o ka cone Weyl ma ke kuhikuhi o ka hoʻolaha ʻana o ke kukui polarized circular, i kapa ʻia ʻo ke kānāwai koho chiral (Kiʻi 1).

ʻO ke aʻo ʻana i nā hanana optical nonlinear o nā mea topological e hoʻohana pinepine i ke ʻano o ka hoʻohui ʻana i ka helu ʻana o nā waiwai o ka mokuʻāina honua a me ka nānā ʻana i ka symmetry. Eia nō naʻe, aia kekahi mau hemahema o kēia ʻano hana: nele ia i ka ʻike dynamic manawa maoli o nā mea lawe i hoʻonāukiuki ʻia i ka wahi momentum a me ka wahi maoli, a ʻaʻole hiki iā ia ke hoʻokumu i kahi hoʻohālikelike pololei me ke ʻano ʻike hoʻokolohua i hoʻoholo ʻia i ka manawa. ʻAʻole hiki ke noʻonoʻo ʻia ka hoʻopili ʻana ma waena o nā electron-phonons a me nā photon-phonons. A he mea koʻikoʻi kēia no kekahi mau hoʻololi pae. Eia kekahi, ʻaʻole hiki i kēia loiloi theoretical e pili ana i ke kumumanaʻo perturbation ke hana me nā kaʻina hana kino ma lalo o ke kahua mālamalama ikaika. ʻO ka simulation time-dependent density functional molecular dynamics (TDDFT-MD) e pili ana i nā loina mua hiki ke hoʻoponopono i nā pilikia i luna.

I kēia mau lā aku nei, ma lalo o ke alakaʻi ʻana a ka mea noiʻi ʻo Meng Sheng, ka mea noiʻi postdoctoral ʻo Guan Mengxue a me ka haumāna doctoral ʻo Wang En o ka SF10 Group o ka State Key Laboratory of Surface Physics o ka Institute of Physics o ka Chinese Academy of Sciences/Beijing National Research Center for Concentrated Matter Physics, me ka laulima ʻana me Polofesa Sun Jiatao o ka Beijing Institute of Technology, ua hoʻohana lākou i ka polokalamu hoʻohālike dynamics excited state TDAP i hoʻomohala ponoʻī ʻia. Ua noiʻi ʻia nā ʻano pane o ka quastiparticle excitation i ka laser ultrafast ma ke ʻano ʻelua o Weyl semi-metal WTe2.

Ua hōʻike ʻia ua hoʻoholo ʻia ka hoʻonāukiuki koho o nā mea lawe kokoke i ka kiko Weyl e ka symmetry orbital atomic a me ke kānāwai koho hoʻololi, kahi ʻokoʻa mai ke kānāwai koho wili maʻamau no ka hoʻonāukiuki chiral, a hiki ke hoʻomalu ʻia kona ala hoʻonāukiuki ma ka hoʻololi ʻana i ke kuhikuhi polarization o ka mālamalama linearly polarized a me ka ikehu photon (FIG. 2).

ʻO ka hoʻonāukiuki asymmetric o nā mea lawe e hoʻoulu ai i nā photocurrents i nā ʻaoʻao like ʻole ma ka lewa maoli, kahi e hoʻopilikia ai i ke kuhikuhi a me ka symmetry o ka interlayer slip o ka ʻōnaehana. ʻOiai ʻo nā waiwai topological o WTe2, e like me ka helu o nā kiko Weyl a me ke kekelē o ka hoʻokaʻawale ʻana ma ka wahi momentum, e hilinaʻi nui ʻia i ka symmetry o ka ʻōnaehana (Kiʻi 3), ʻo ka hoʻonāukiuki asymmetric o nā mea lawe e lawe mai i nā ʻano hana like ʻole o nā quastiparticles Weyl ma ka lewa momentum a me nā loli e pili ana i nā waiwai topological o ka ʻōnaehana. No laila, hāʻawi ke aʻo ʻana i kahi kiʻikuhi pae maopopo no nā hoʻololi pae phototopological (Kiʻi 4).

Hōʻike nā hopena e pono e nānā ʻia ke chirality o ka hoʻonāukiuki ʻana o ka mea lawe ma kahi kokoke i ka wahi ʻo Weyl, a pono e kālailai ʻia nā waiwai orbital atomic o ka hana nalu. Ua like nā hopena o nā mea ʻelua akā ʻokoʻa ke ʻano hana, kahi e hāʻawi ai i kahi kumu kumumanaʻo no ka wehewehe ʻana i ka singularity o nā wahi ʻo Weyl. Eia kekahi, hiki i ke ʻano helu i hoʻohana ʻia ma kēia haʻawina ke hoʻomaopopo hohonu i nā pilina paʻakikī a me nā ʻano dynamical ma nā pae atomic a me nā uila i kahi manawa wikiwiki loa, e hōʻike i kā lākou mau ʻano hana microphysical, a manaʻo ʻia he mea hana ikaika no ka noiʻi e hiki mai ana ma nā hanana optical nonlinear i nā mea topological.

Aia nā hualoaʻa ma ka puke pai ʻo Nature Communications. Kākoʻo ʻia ka hana noiʻi e ka National Key Research and Development Plan, ka National Natural Science Foundation a me ka Strategic Pilot Project (Category B) o ka Chinese Academy of Sciences.

FIG.1.a. ʻO ke kānāwai koho chirality no nā kiko Weyl me ka hōʻailona chirality maikaʻi (χ = + 1) ma lalo o ke kukui polarized circular; Hoʻonāukiuki koho ma muli o ka symmetry orbital atomic ma ke kiko Weyl o b. χ = + 1 ma ka mālamalama polarized pūnaewele

KII. 2. Kiʻikuhi hoʻonohonoho ʻātoma o a, Td-WTe2; b. Hoʻonohonoho ʻana o ka hui kokoke i ka ʻili Fermi; (c) Hoʻonohonoho ʻana o ka hui a me nā haʻawina pili o nā orbitals atomic i hoʻolaha ʻia ma nā laina symmetric kiʻekiʻe ma ka ʻāpana Brillouin, hōʻike nā pua (1) a me (2) i ka hoʻonāukiuki kokoke a mamao paha mai nā kiko Weyl, kēlā me kēia; d. Hoʻonui ʻia o ka hoʻonohonoho ʻana o ka hui ma ke kuhikuhi Gamma-X

FIG.3.ab: Ua hōʻike ʻia ka neʻe ʻana o ka papa kuhikuhi polarization mālamalama linearly polarized ma ke axis A a me ke axis B o ke kristal, a me ke ʻano neʻe like; C. Hoʻohālikelike ma waena o ka simulation theoretical a me ka nānā ʻana i ka hoʻokolohua; de: Ka ulu ʻana o ka symmetry o ka ʻōnaehana a me ke kūlana, ka helu a me ke kekelē o ka hoʻokaʻawale ʻana o nā kiko Weyl kokoke loa ʻelua ma ka mokulele kz=0

Kiʻi 4. Hoʻololi pae phototopological ma Td-WTe2 no ka ikehu photon māmā polarized linearly (?) ω) a me ke kiʻikuhi pae e pili ana i ke kuhikuhi polarization (θ)