PHOTON MILIYAN 100 A DAƘIƘA DAGA MOLECULE ƊAYA

Sadarwar quantum, hanyoyin sadarwa na quantum da kwamfutocin quantum na haske duk sun dogara ne ga wani muhimmin sashi guda: tushen photon ɗaya, na’urar da ke fitar da haske photon ɗaya a lokaci guda, idan an buƙata, kuma kowane photon yana kama da na gaba.

Akwai zaɓuɓɓuka da yawa: atom guda-guda, ions da aka kama, ɗigon quantum na semiconductor (quantum dots) — waɗanda suka fi girma a fasaha — da lahani a cikin lu’u-lu’u ko silicon. Molecule na kwayoyin halitta (organic) wata hanya ce daban. Ilimin sinadarai ne ke tsara su, atom bayan atom, kuma ana iya sake samar da su daidai; ana iya zaɓar launinsu ta hanyar tsara molecule ɗin. Ƙanana ne kuma masu araha wajen ƙera su. Idan aka sanyaya su kusa da sifili cikakke (absolute zero) a cikin crystal mai masauki, suna fitar da haske mafi tsarki da zai yiwu a bakan launi kuma kusan ba sa taɓa lalacewa.

Matsalar: rasa hasken

Mai fitar da haske yana aika haske ta kowace alƙibla, kuma yawancinsa yana maƙalewa a cikin kayan saboda cikakken komawar haske a ciki (total internal reflection). Photon da ya kauce wa ruwan tabarau na farko ya tafi kenan har abada. Hanyoyin magance wannan da aka saba — ƙananan kogo (microcavities), siraran wayoyi na nano (nanowires) — suna buƙatar sassaka kayan. A nan hakan ba zai yiwu ba: crystal na kwayoyin halitta da ke ba da haske mafi kyau masu rauni ne kuma ba sa tsira daga hanyoyin ƙera su.

Madubi, kubba da shimfiɗa ta nanometre 140

Ƙungiyar Stephan Götzinger a Cibiyar Max Planck ta Kimiyyar Haske da ke Erlangen ta yi amfani da eriya mai faɗi (planar antenna) maimakon haka. Madubin azurfa yana ƙarƙashin shimfiɗar silica. A sama, wani rabin ƙwallo na zirconium oxide — “ruwan tabarau mai nutsewa mai ƙarfi” (solid immersion lens) — an manna shi kai tsaye a kan tushe, yana barin wata hanya mai kaurin nanometre 140 kawai. Ana cika wannan hanya da crystal na kwayoyin halitta da aka narkar (1,4-dichlorobenzene) wanda ke ɗauke da ’yan molecule na dibenzoterrylene, sannan ya daskare.

Ana karkatar da hasken zuwa kubba mai babban ma’aunin lanƙwasa haske; madubin kuma yana mayar da abin da zai kuɓuta ta ɗaya gefen. Mafi muhimmanci, ba a taɓa sassaka crystal ɗin kansa ba: dukkan tsarawar tana cikin tushen. Eriyar ba ta dogara ga wani ƙunƙuntaccen amsa-kuwwa (resonance) ba, don haka tana aiki a kan launuka masu yawa kuma da ƙyar ta dogara ga yadda molecule ɗin ya fuskanta. Ana sanyaya samfurin zuwa kelvin 1.4 (−271.75 °C).

Lambobin

Ingancin tattarawa: 97 ± 2 % na hasken yana isa ga ruwan tabarau na farko.
Kusan photon miliyan 100 a daƙiƙa ana tattarawa daga molecule ɗaya a kan dukkan bakan launinsa — a cewar marubutan, mafi girman adadin da aka taɓa bayar da rahoto ga kowane tushen photon ɗaya mai tsananin sanyi (cryogenic), komai dandalin. Adadin da aka gano, ƙidaya miliyan 21.3 a daƙiƙa, ya ninka sau goma na tushen molecule masu tsananin sanyi na baya.
Tsarki: fiye da 97.5 % — photon ɗin lallai suna fitowa ɗaya bayan ɗaya, ko da a ƙarƙashin tunzurawa mai ƙarfi.
Rashin bambantuwa (indistinguishability): 91.2 ± 2.3 % — yadda photon masu bin juna suke kama da juna, wanda ɗan ƙaramin rashin daidaituwa (coherence) da ya rage ke iyakancewa.
Photon biyu da aka fitar da tazarar nanosecond 170.7 har yanzu suna tsoma baki da juna (interference) a fili sosai.
A matsayin ƙarin sakamako, ƙungiyar ta auna cewa molecule ɗin yana mayar da kusan 90 % na tunzurawarsa zuwa haske — ƙiyasi na farko kai tsaye a ƙaramin zafi ga wannan molecule.

Molecule na kwayoyin halitta sun shiga gasar

Sakamakon ya sanya molecule na kwayoyin halitta cikin dandamali masu gasa don photon ɗaya: masu haske, tsarkakakku kuma masu daidaituwa a lokaci guda. Tun da eriyar ba ta buƙatar a daidaita ta ga wani molecule na musamman, marubutan suna sa ran za ta yi aiki da wasu nau’i-nau’i na molecule da crystal, don haka a wasu launuka ma. Burinsu na gaba: daidaita molecule da yawa maƙwabta zuwa mita (frequency) ɗaya don samar da yanayin quantum na haske masu sarƙaƙiya — mataki zuwa hanyoyin sadarwa na quantum photonic na gaba.