I-Superconductivity iyinto ebonakalayo lapho ukumelana kukagesi kwezinto kwehla khona kuye ku-zero ekushiseni okuthile okubucayi. Ithiyori ye-Bardeen-Cooper-Schrieffer (BCS) iyincazelo ephumelelayo, echaza i-superconductivity ezintweni eziningi. Iveza ukuthi ama-Cooper electron pair akhiwa ku-crystal lattice ekushiseni okuphansi ngokwanele, nokuthi i-BCS superconductivity ivela ekujiya kwawo. Nakuba i-graphene ngokwayo ingumqhubi kagesi omuhle kakhulu, ayibonisi i-BCS superconductivity ngenxa yokucindezelwa kokuxhumana kwe-electron-phonon. Yingakho iningi labaqhubi “abahle” (njengegolide nethusi) beyi-superconductor “ababi”.
Abacwaningi e-Center for Theoretical Physics of Complex Systems (PCS) e-Institute of Basic Science (IBS, South Korea) babike indlela entsha ehlukile yokufeza i-superconductivity ku-graphene. Bafeze lokhu ngokuphakamisa uhlelo oluhlanganisiwe olwakhiwe nge-graphene kanye ne-Bose-Einstein condensate (BEC) enezinhlangothi ezimbili. Ucwaningo lushicilelwe kumagazini i-2D Materials.
Uhlelo oluhlanganisiwe oluqukethe igesi yama-electron (ungqimba oluphezulu) ku-graphene, oluhlukaniswe ne-Bose-Einstein condensate enezinhlangothi ezimbili, emelelwa ama-exciton angaqondile (izendlalelo eziluhlaza okwesibhakabhaka nezibomvu). Ama-electron nama-exciton ku-graphene ahlanganiswe ngamandla e-Coulomb.
(a) Ukuncika kwezinga lokushisa kwegebe le-superconducting enqubweni eqondiswa yi-bogolon ngokulungiswa kwezinga lokushisa (umugqa onamachashazi) nangaphandle kokulungiswa kwezinga lokushisa (umugqa oqinile). (b) Izinga lokushisa elibucayi lokuguqulwa kwe-superconducting njengomsebenzi wobuningi be-condensate ekusebenzelaneni okuqondiswa yi-bogolon nokulungiswa kwezinga lokushisa (umugqa obomvu onechashazi) nangaphandle (komugqa omnyama oqinile). Umugqa onamachashazi aluhlaza okwesibhakabhaka ubonisa izinga lokushisa lokuguquka kwe-BKT njengomsebenzi wobuningi be-condensate.
Ngaphezu kokusebenzisa amandla amakhulu, i-BEC ingenye into eyenzeka emazingeni okushisa aphansi. Yisimo sesihlanu sento esibikezelwe okokuqala ngu-Einstein ngo-1924. Ukwakheka kwe-BEC kwenzeka lapho ama-athomu anamandla aphansi ehlangana ndawonye futhi engena esimweni esifanayo samandla, okuwumkhakha wocwaningo olunzulu ku-physics yezinto ezihlanganisiwe. Uhlelo lwe-hybrid Bose-Fermi empeleni lumelela ukusebenzisana kwengqimba yama-electron enengqimba yama-boson, njenge-excitons engaqondile, i-exciton-polaron, njalo njalo. Ukusebenzisana phakathi kwezinhlayiya ze-Bose ne-Fermi kwaholela ezimweni ezahlukahlukene ezintsha nezithakazelisayo, ezavusa isithakazelo samaqembu womabili. Umbono oyisisekelo nogxile ekusetshenzisweni.
Kulo msebenzi, abacwaningi babike indlela entsha yokwenza i-superconducting ku-graphene, okubangelwa ukusebenzisana phakathi kwama-electron nama-"bogolon" esikhundleni sama-phononi ohlelweni olujwayelekile lwe-BCS. Ama-Bogolon noma ama-Bogoliubov quasiparticles ayizici ku-BEC, anezici ezithile zezinhlayiya. Ngaphakathi kwezigaba ezithile zamapharamitha, le ndlela ivumela izinga lokushisa elibucayi le-superconducting ku-graphene ukuthi lifinyelele ku-70 Kelvin. Abacwaningi bathuthukise futhi inkolelo entsha ye-BCS encane egxile kakhulu ezinhlelweni ezisekelwe ku-graphene entsha ehlanganisiwe. Imodeli abayiphakamisile iphinde ibikezele ukuthi izakhiwo ze-superconducting zinganda ngokushisa, okuholela ekuncikeni kokushisa okungeyona i-monotonic kwegebe le-superconducting.
Ngaphezu kwalokho, izifundo zibonise ukuthi ukusabalala kwe-graphene nge-Dirac kugcinwe kulolu hlelo oluqondiswa yi-bogolon. Lokhu kubonisa ukuthi le ndlela yokwenza i-superconducting ihilela ama-electron anokusabalala okuhlobene, futhi lesi simo asikahlolwa kahle ku-condensed matter physics.
Lo msebenzi wembula enye indlela yokufeza i-superconductivity yokushisa okuphezulu. Ngesikhathi esifanayo, ngokulawula izakhiwo ze-condensate, singalungisa i-superconductivity ye-graphene. Lokhu kubonisa enye indlela yokulawula amadivayisi e-superconductivity esikhathini esizayo.
Isikhathi sokuthunyelwe: Julayi-16-2021 
