"Kwayoyin Invisibility" har yanzu ba a ganuwa

Sabuwar a cikin jerin "hanyoyin ganuwa" ɗaya ne daga Jami'ar Rochester (1), wanda ke amfani da tsarin gani mai dacewa. Duk da haka, masu shakka suna kiran wannan wani nau'i na yaudara ko tasiri na musamman, wanda tsarin ruwan tabarau mai wayo ya hana haske kuma ya yaudari hangen nesa na mai kallo.

Akwai wasu kyawawan lissafi na ci gaba a bayansa duka-masana kimiyya suna amfani da shi don gano yadda ake daidaita ruwan tabarau biyu ta yadda hasken ya karye ta yadda abin da ke bayansu zai iya ɓoye. Wannan bayani yana aiki ba kawai lokacin kallon kai tsaye a kan ruwan tabarau ba - kusurwar digiri 15 ko wani ya isa.

1. "Cap of Invisibility" daga Jami'ar Rochester.

Ana iya amfani da shi a cikin motoci don kawar da makafi a cikin madubai ko a cikin dakunan aiki ta hanyar barin likitocin su gani ta hannunsu. Wannan shi ne wani a cikin dogon jerin wahayi game da fasaha mara ganuwawadanda suka zo mana a cikin 'yan shekarun nan.

A cikin 2012, mun riga mun ji labarin "Cap of Invisibility" daga Jami'ar Duke ta Amurka. Sai dai wanda ya fi bincike a lokacin cewa ya kasance game da rashin ganuwa na ƙaramin silinda a cikin ɗan ƙaramin juzu'i na bakan microwave. Shekara guda da ta gabata, jami'an Duke sun ba da rahoton fasahar satar fasaha don sonar wanda zai iya zama alama mai ban sha'awa a wasu da'irori.

Abin baƙin ciki, shi ne game da ganuwa kawai daga wani ra'ayi da kuma a cikin kunkuntar ikon yinsa, wanda ya sa fasahar ba ta da amfani. A cikin 2013, injiniyoyi marasa gajiyawa a Duke sun ba da shawarar na'urar da aka buga ta 3D wacce ta rufe wani abu da aka sanya a ciki tare da ƙananan ramuka a cikin tsarin (2). Duk da haka, kuma, wannan ya faru a cikin iyakacin iyaka kuma daga wani ra'ayi kawai.

A cikin hotunan da aka buga a Intanet, cape na kamfanin Kanada Hyperstealth, wanda a cikin 2012 aka tallata a ƙarƙashin sunan mai ban sha'awa Quantum Stealth (3), ya yi kyau. Abin takaici, ba a taɓa nuna samfuran aiki ba kuma ba a taɓa bayyana yadda yake aiki ba. Kamfanin ya bayyana matsalolin tsaro a matsayin dalili kuma a asirce ya bayar da rahoton cewa yana shirya nau'ikan samfurin na sirri ga sojoji.

Duban gaba, kyamarar baya

Na farko na zamanihular ganuwa» Injiniya dan kasar Japan Prof. Susumu Tachi daga Jami'ar Tokyo. Ya yi amfani da kyamarar da aka ajiye a bayan wani mutum sanye da riga, wanda kuma ya ninka a matsayin abin dubawa. Hoto daga kyamarar baya an zana shi. Mutumin da ke cikin alkyabbar "ba a ganuwa". Irin wannan dabarar ana amfani da ita ta na'urar Adaptiv don kama motocin yaƙi, wanda BAE Systems (4) ya gabatar a cikin shekaru goma da suka gabata.

Yana nuna hoton infrared "daga baya" akan sulke na tanki. Irin wannan motar ba za a iya gani kawai a cikin na'urorin gani ba. Tunanin masking abubuwa ya kasance a cikin 2006. John Pendry na Kwalejin Imperial London da David Schurig da David Smith na Jami'ar Duke sun buga ka'idar "Tsarin gani" a cikin mujallar Kimiyya kuma sun gabatar da yadda yake aiki a cikin yanayin microwaves (tsawon tsayi fiye da haske mai gani).

2. "Hat ɗin Invisibility" da aka buga a cikin girma uku.

Tare da taimakon metamaterials masu dacewa, za a iya lankwasa igiyar lantarki ta hanyar da za a ketare wani abu da ke kewaye da kuma komawa hanyar da yake yanzu. Ma'aunin da ke nuna cikakkiyar amsawar gani na matsakaici shine ma'anar refractive, wanda ke ƙayyade sau nawa a hankali fiye da a cikin haske mai motsi a cikin matsakaici. Muna ƙididdige shi azaman tushen samfurin ƙarancin wutar lantarki da ƙarfin maganadisu.

Izinin lantarki dangi; yana ƙayyade sau nawa ƙarfin hulɗar lantarki a cikin wani abu da aka ba shi ya kasa da ƙarfin hulɗar a cikin vacuum. Saboda haka, ma'auni ne na yadda ƙarfin cajin lantarki a cikin wani abu ke amsawa ga filin lantarki na waje. Yawancin abubuwa suna da tabbataccen dielectric akai-akai, wanda ke nufin cewa filin da aka gyara ta hanyar abu har yanzu yana da ma'ana ɗaya da filin waje.

Iyakar maganadisu na dangi m yana ƙayyade yadda filin maganadisu ke canzawa a cikin sarari da ke cike da abu da aka bayar idan aka kwatanta da filin maganadisu wanda zai wanzu a cikin injin da yake da tushen filin maganadisu na waje. Ga duk abubuwan da ke faruwa a zahiri, ƙarfin maganadisu yana da inganci. Don kafofin watsa labarai masu gaskiya kamar gilashi ko ruwa, duk nau'ikan guda uku suna da inganci.

Sa'an nan haske, wucewa daga injin ko iska (ma'auni na iska sun ɗan bambanta da vacuum) zuwa cikin matsakaici, an rushe shi bisa ga ka'idar refraction da rabo daga sine na kusurwar abin da ya faru zuwa sine na kusurwar. refraction daidai yake da fihirisar refractive don matsakaicin da aka ba. Darajar bai kai sifili ba; kuma m yana nufin cewa electrons da ke cikin matsakaita suna tafiya ta hanyar da ta saba da ƙarfin da filin lantarki ko maganadisu ya haifar.

Wannan shi ne ainihin abin da ke faruwa a cikin karafa, wanda iskar gas na lantarki kyauta ke jujjuyawa nasa. Idan mitar igiyar wutar lantarki ba ta wuce mitar waɗannan motsin motsin na'urorin lantarki ba, to waɗannan motsin suna duba filin wutar lantarkin yadda ya kamata ta yadda ba za su ƙyale shi ya shiga zurfin ƙarfe ba har ma ya haifar da filin da aka nufa. kishiyar filin waje.

A sakamakon haka, dielectric akai-akai na irin wannan abu ne mara kyau. Rashin iya shiga zurfin cikin karfen, hasken lantarki na lantarki yana nunawa daga saman karfen, kuma karfen da kansa yana samun haske mai mahimmanci. Menene idan duka nau'ikan dielectric akai-akai sun kasance mara kyau? An yi wannan tambayar a shekara ta 1967 ta masanin kimiyyar lissafi na Rasha Viktor Veselago. Ya bayyana cewa ma'anar refractive na irin wannan matsakaici ba shi da kyau kuma haske yana raguwa gaba ɗaya fiye da abin da ya biyo baya daga ka'idar da aka saba.

5. Ragewa mara kyau akan saman ma'auni - gani

Sa'an nan kuma ƙarfin wutar lantarki na lantarki yana canjawa zuwa gaba, amma maɗaukakin igiyoyin lantarki suna motsawa zuwa alkiblar da ta saba da siffar bugun jini da makamashin da aka canjawa. Irin waɗannan kayan ba su wanzu a cikin yanayi (babu abubuwan da ke da ƙarancin magnetic). Abubuwan da aka ambata na 2006 da aka ambata kawai da sauran wallafe-wallafen da aka ƙirƙira a cikin shekaru masu zuwa ne kawai suka iya kwatantawa don haka gina gine-ginen wucin gadi tare da maƙasudi mara kyau (5).

An kira su metamaterials. Ma'anar kalmar Helenanci "meta" tana nufin "bayan", wato, waɗannan sifofi ne da aka yi daga kayan halitta. Metamaterials suna samun kaddarorin da suke buƙata ta hanyar gina ƙananan da'irori na lantarki waɗanda ke kwaikwayi halayen maganadisu ko lantarki na kayan. Yawancin karafa suna da ƙarancin wutar lantarki mara kyau, don haka ya isa ya bar ɗakin don abubuwan da ke ba da amsawar maganadisu mara kyau.

Maimakon ƙarfe mai kama da juna, yawancin siraran wayoyi na ƙarfe da aka tsara a cikin grid mai cubic ana manne da farantin kayan rufewa. Ta hanyar canza diamita na wayoyi da nisa tsakanin su, zaku iya daidaita ƙimar mitar wanda tsarin zai sami ƙarancin wutar lantarki mara kyau. Don samun ƙarancin ƙarfin maganadisu mara kyau a cikin mafi sauƙi, ƙirar ta ƙunshi zobba biyu da aka karye waɗanda aka yi da mai jagora mai kyau (alal misali, zinariya, azurfa ko jan ƙarfe) kuma an raba shi da wani Layer na wani abu.

Wannan tsarin ana kiransa resonator mai raba zobe - an gajarta shi da SRR. Resonator mai raba zobe (6). Saboda gibin da ke cikin zoben da tazarar da ke tsakanin su, yana da wani capacitance, kamar capacitor, kuma tun da zoben an yi su ne da kayan aiki, shi ma yana da wani inductance, watau. iya samar da igiyoyin ruwa.

Canje-canje a filin maganadisu na waje daga igiyoyin lantarki suna haifar da halin yanzu yana gudana a cikin zoben, kuma wannan halin yanzu yana haifar da filin maganadisu. Ya bayyana cewa tare da ƙirar da ta dace, filin maganadisu da tsarin ya haifar yana karkata zuwa filin waje. Wannan yana haifar da ƙarancin maganadisu mara kyau na kayan da ke ɗauke da irin waɗannan abubuwan. Ta hanyar saita ma'auni na tsarin metamaterial, yana yiwuwa a sami amsawar maganadisu mara kyau a cikin kewayon mitoci masu faɗin gaske.

Meta - gini

Mafarkin masu zanen shine gina tsarin da raƙuman ruwa zasu gudana a kusa da wani abu (7). A shekara ta 2008, masana kimiyya a Jami'ar California, Berkeley, sun ƙirƙiri kayan aiki na farko na farko masu girma uku waɗanda ke da maƙasudi mara kyau don bayyane da haske na kusa da infrared, suna lanƙwasa haske a kishiyar alkiblarsa. Sun ƙirƙiri sabon metamaterial ta hanyar haɗa azurfa da magnesium fluoride.

Sa'an nan kuma a yanka a cikin matrix wanda ya ƙunshi ƙananan allura. An lura da abin da ya faru na raƙuman raƙuman raƙuman raƙuman raƙuman raƙuman raƙuman ruwa na 1500 nm (kusa da infrared). A farkon 2010, Tolga Ergin daga Cibiyar Fasaha ta Karlsruhe da abokan aikinsa daga Kwalejin Imperial ta London suka kirkiro. marar ganuwa low katako labule. Masu binciken sun yi amfani da kayan da ake samu a kasuwa.

Sun yi amfani da lu'ulu'u na photonic da aka shimfiɗa a saman ƙasa don rufe wani ɗan ƙaramin haske a kan farantin zinariya. Wannan shine yadda aka ƙirƙirar metamaterial daga ruwan tabarau na musamman. Gilashin ruwan tabarau da ke gaban hump a kan farantin yana samuwa a cikin hanyar da, ta hanyar karkatar da wani ɓangare na raƙuman haske, suna kawar da watsawar haske a kan kullun. Ta hanyar lura da farantin a ƙarƙashin na'urar hangen nesa, ta yin amfani da haske mai tsayi kusa da na hasken da ake iya gani, masana kimiyya sun ga farantin lebur.

Daga baya, masu bincike daga Jami'ar Duke da Kwalejin Imperial ta Landan sun sami nasarar samun mummunan ra'ayi na radiation na microwave. Don cimma wannan tasirin, ɗayan abubuwan da ke cikin tsarin metamaterial dole ne su kasance ƙasa da tsawon haske. Don haka wannan aiki ne mai ƙalubale a fasaha, yana buƙatar samar da ƙananan sifofin metamaterial waɗanda suka dace da tsawon hasken da suke buƙatar ja da baya.

Hasken bayyane (violet zuwa ja) yana da tsawon nanometer 380 zuwa 780 (nanometer shine biliyan ɗaya na mita). Kwararru a fannin fasahar Nanotechnology daga Jami’ar Scotland ta St. Andrews ne suka kawo dauki. Sun sami Layer guda ɗaya na metamaterial tare da raga mai yawa. The New Journal of Physics ya bayyana metaflex wanda zai iya lanƙwasa tsawon raƙuman ruwa a kusa da nanometer 620 (hasken orange-ja).

A cikin 2012, ƙungiyar masu bincike na Amurka daga Jami'ar Texas a Austin sun gabatar da wata dabara ta daban ta amfani da microwaves. An lulluɓe silinda mai diamita na 18 cm tare da kayan plasma tare da rashin ƙarfi mara kyau, yana ba da damar yin amfani da kaddarorin. Idan yana da daidai kishiyar kayan gani na gani zuwa abu mai ɓoye, yana haifar da wani nau'in "mara kyau".

Don haka, raƙuman ruwa biyu suna haɗuwa kuma abin ya zama marar ganuwa. Sakamakon haka, kayan na iya lanƙwasa jeri daban-daban na igiyoyin igiyar ruwa don su gudana a kusa da abin, suna haɗuwa a ɗayan gefensa, wanda zai iya zama alama ga mai kallo na waje. Ka'idodin ka'idoji suna haɓaka.

Kimanin watanni goma sha biyu da suka gabata, wata kasida ta bayyana a cikin Advanced Optical Materials game da wani binciken da masana kimiyya suka yi a Jami'ar Central Florida. Wanene ya san idan sun kasa shawo kan ƙuntatawa na yanzu akan "huluna marasa ganuwa»Gina daga metamaterials. Dangane da bayanan da suka buga, yana yiwuwa wani abu ya ɓace a cikin kewayon hasken da ake gani.

7. Hanyoyi na ka'ida na lankwasa haske akan abu marar ganuwa

Debashis Chanda da tawagarsa sun bayyana yadda ake amfani da na'urar metamaterial tare da tsari mai girma uku. Mun yi nasarar samun ta godiya ga abin da ake kira. nanotransfer bugu (NTP), samar da karfe-dielectric kaset. Za'a iya canza ma'anar refractive ta amfani da hanyoyin nanoengineering. Dole ne a sarrafa hanyar yaɗa hasken a cikin tsari mai girma uku na kayan ta amfani da fasahar resonance electromagnetic.

Masana kimiyya sun yi taka tsantsan a cikin abin da suka yanke, amma daga bayanin fasaharsu ya bayyana sarai cewa rufin da aka yi daga irin wannan abu yana da ikon karkatar da igiyoyin lantarki da muhimmanci. Bugu da ƙari, hanyar samun sabon kayan yana ba da damar samar da manyan wurare, wanda ya sa wasu sun riga sun yi mafarki na mayakan da aka rufe da irin wannan kama da za su samar da su. ganuwa cikakke, daga radar zuwa hasken rana.

Rufe na'urori masu amfani da metamaterials ko dabarun gani ba sa haifar da ainihin bacewar abubuwa, amma rashin ganinsu kawai yana nufin ganowa, kuma nan da nan, maiyuwa, ga ido. Koyaya, an riga an sami ƙarin ra'ayoyi masu tsattsauran ra'ayi. Jeng Yi Lee da Ray-Kuang Lee daga Jami'ar Tsing Hua ta Taiwan sun ba da shawarar ra'ayi na kididdigar kididdigar "wurin ganuwa" wanda zai iya kawar da abubuwa ba kawai daga gani ba, har ma daga gaskiya gaba ɗaya.

Wannan zai yi aiki kama da abin da aka tattauna a sama, amma maimakon ma'aunin Maxwell, za a yi amfani da lissafin Schrödinger. Manufar ita ce a shimfiɗa filin yuwuwar abu don ya zama daidai da sifili. Wannan a ra'ayi yana yiwuwa akan microscale. Duk da haka, zai ɗauki lokaci mai tsawo don jira damar fasaha na kera irin wannan murfin. Kama da kowane"hular ganuwa", game da abin da za mu iya cewa da gaske ta boye wani abu daga gare mu.