"Ama-Invisibility Caps" awabonakali

Okwakamuva ochungechungeni lwe "izingubo zokungabonakali" yilowo ozelwe eNyuvesi yaseRochester (1), esebenzisa uhlelo olufanele lwe-optical. Nokho, abangabazayo bakubiza ngokuthi uhlobo oluthile lweqhinga lokukhohlisa noma umphumela okhethekile, lapho isimiso se-lens esihlakaniphile sihlanza ukukhanya futhi sidukise umbono womuntu obukele.

Kukhona izibalo ezithuthuke kakhulu ngemuva kwakho konke—ososayensi badinga ukuzisebenzisa ukuze bathole indlela yokusetha amalensi amabili ukuze ukukhanya kukhanye ngendlela yokuthi bakwazi ukufihla into ngemva kwawo. Lesi sixazululo asisebenzi kuphela uma ubheka ngqo kuma-lens - i-angle ye-degrees engu-15 noma enye yanele.

1. "Invisibility Cap" evela eNyuvesi yaseRochester.

Ingasetshenziswa ezimotweni ukuze kususwe izindawo ezingaboni emehlweni ezibukweni noma emakamelweni okuhlinza, okuvumela odokotela abahlinzayo ukuba babone ngezandla zabo. Lokhu kungenye ochungechungeni olude lwezambulo mayelana ubuchwepheshe obungabonakaliezifike kithi eminyakeni yamuva.

Ngo-2012, sesivele sezwa nge-"Cap of Invisibility" evela e-American Duke University. Okwakufundeka kakhulu ngaleso sikhathi ukuthi kwakumayelana nokungabonakali kwesilinda esincane esiqeshini esincane se-microwave spectrum. Ngonyaka odlule, izikhulu zikaDuke zabika ngobuchwepheshe be-sonar stealth obungase bubonakale buthembisa kweminye imibuthano.

Ngeshwa, kwaba ukungabonakali kuphela ngombono othile kanye nobubanzi obuncane, okwenza ubuchwepheshe bungasetshenziswa kancane. Ngo-2013, onjiniyela abangakhathali e-Duke bahlongoza idivayisi ephrintiwe ye-3D eyafihla into ebekwe ngaphakathi enezimbobo ezincane esakhiweni (2). Nokho, futhi, lokhu kwenzeka ebangeni elilinganiselwe lamagagasi futhi kuphela ngombono othile.

Ezithombeni ezishicilelwe ku-inthanethi, i-cape yenkampani yaseCanada i-Hyperstealth yayibukeka ithembisa, okwathi ngo-2012 yakhangiswa ngegama elithakazelisayo elithi Quantum Stealth (3). Ngeshwa, ama-prototypes asebenzayo awakaze aboniswe, futhi akukaze kuchazwe ukuthi kusebenza kanjani. Inkampani icaphuna izinkinga zokuphepha njengesizathu futhi ibika ngokufihlekile ukuthi ilungiselela amasosha izinguqulo eziyimfihlo zomkhiqizo.

Imonitha yangaphambili, ikhamera yangemuva

Okokuqala yesimanjeukungabonakali cap» Yethulwe eminyakeni eyishumi edlule ngunjiniyela waseJapan uProf. Susumu Tachi waseNyuvesi yaseTokyo. Wasebenzisa ikhamera ebekwe ngemuva kwendoda egqoke ijazi nayo eyayiyimonitha. Isithombe esivela kukhamera engemuva sakhishelwa kuyo. Indoda egqoke ingubo "yayingabonakali". Iqhinga elifanayo lisetshenziswa idivayisi yokufihla imoto ye-Adaptiv eyethulwe eshumini leminyaka eledlule yi-BAE Systems (4).

Ibonisa isithombe se-infrared "ngemuva" kuzikhali zethangi. Umshini onjalo awubonakali emishinini yokubona. Umqondo wokufihla izinto wavela ngo-2006. UJohn Pendry wase-Imperial College London, uDavid Schurig noDavid Smith baseDuke University bashicilele inkolelo-mbono "ye-transformation optics" kumagazini iSayensi futhi bethula indlela esebenza ngayo endabeni yama-microwave (amaza amade amaza kunokukhanya okubonakalayo).

2. "Ikepisi elingabonakali" eliphrintwe ngezinhlangothi ezintathu.

Ngosizo lwe-metamatadium efanele, igagasi kazibuthe lingagotshwa ngendlela yokuthi lidlule into ezungezile bese libuyela endleleni yalo yamanje. Ipharamitha ekhombisa ukusabela okujwayelekile kokubona kwendawo okumaphakathi inkomba ye-refractive, enquma ukuthi kuhamba kancane kangaki kune-vacuum, ukukhanya kuhamba kule medium. Sibala njengempande yomkhiqizo wokufinyeleleka okuhlobene kukagesi kanye nozibuthe.

amandla kagesi ahambisanayo; inquma ukuthi amandla okusebenzelana kagesi entweni ethile angaphansi kangaki amandla okusebenzelana aku-vacuum. Ngakho-ke, isilinganiso sokuthi amashaji kagesi ngaphakathi kwento asabela aqine kangakanani endaweni kagesi yangaphandle. Izinto eziningi zinemvume evumayo, okusho ukuthi inkambu eshintshwe into isenencazelo efanayo neyenkambu yangaphandle.

Ukungena kukazibuthe okuhlobene m kunquma ukuthi inkambu kazibuthe ishintsha kanjani endaweni egcwele into ethile, uma kuqhathaniswa nendawo kazibuthe engaba khona endaweni engenalutho enomthombo ofanayo wangaphandle uzibuthe. Kuzo zonke izinto ezenzeka ngokwemvelo, amandla kazibuthe ahlobene alungile. Kumidiya ebonisa ngale njengengilazi noma amanzi, womathathu amanani aqondile.

Khona-ke ukukhanya, okudlula ku-vacuum noma emoyeni (amapharamitha omoya ahluke kancane kuphela ku-vacuum) kuya endaweni ephakathi, kuyaphikiswa ngokuvumelana nomthetho wokuphikiswa kanye nesilinganiso se-sine ye-angle yesigameko kuya ku-sine ye-engeli ye-refraction. ilingana nenkomba ye-refractive yalesi sisetshenziswa. Inani lingaphansi kukaziro; futhi m kusho ukuthi ama-electron angaphakathi kwendawo ephakathi ahamba aye ohlangothini oluphambene namandla adalwe yinkundla kagesi noma kazibuthe.

Yilokhu kanye okwenzeka ezinsimbi, lapho igesi ye-electron yamahhala ingena khona ngokuzungeza kwayo. Uma i-frequency ye-electromagnetic wave ingeqi imvamisa yalawa ma-oscillation emvelo ama-electron, khona-ke lawa ma-oscillations ahlola insimu kagesi yegagasi ngokuphumelelayo kangangokuthi awakuvumeli ukuba kungene ekujuleni kwensimbi futhi kudale ngisho nenkundla eqondiswe ngokuphambene. ensimini yangaphandle.

Ngenxa yalokho, imvume yezinto ezinjalo ayilungile. Ayikwazi ukungena ekujuleni kwensimbi, imisebe ye-electromagnetic ibonakala ebusweni bensimbi, futhi insimbi ngokwayo ithola ukukhazimula kwesici. Kuthiwani uma zombili izinhlobo zemvume bezingezinhle? Lo mbuzo wabuzwa ngo-1967 isazi sesayensi yemvelo saseRussia uViktor Veselago. Kuvela ukuthi inkomba ye-refractive ye-medium enjalo inegethivu futhi ukukhanya kunqanyuliwe ngendlela ehluke ngokuphelele kunokulandelayo emthethweni ojwayelekile wokuphikisa.

5. I-refraction engalungile ebusweni be-metamaterial - ukubona ngeso

Khona-ke amandla egagasi kazibuthe kagesi adluliselwe phambili, kodwa ubukhulu begagasi kazibuthe bunyakaza bubheke kolunye uhlangothi kuya ekumiseni komfutho namandla adlulisiwe. Izinto ezinjalo azikho emvelweni (azikho izinto ezinokungena okungalungile kazibuthe). Kuphela ekushicilelweni kwe-2006 okukhulunywe ngenhla nakwezinye izincwadi eziningi ezakhiwe eminyakeni eyalandela, kwakungenzeka ukuchaza futhi, ngakho-ke, ukwakha izakhiwo zokwenziwa nge-negative refractive index (5).

Abizwa ngokuthi ama-metamatadium. Isiqalo sesiGreki esithi "meta" sisho "ngemuva", okungukuthi, lezi yizakhiwo ezenziwe ngezinto zemvelo. I-Metamatadium ithola izici ezizidingayo ngokwakha amasekhethi kagesi amancane alingisa izici zikazibuthe noma zikagesi zento esebenzayo. Izinsimbi eziningi zinokungena kahle kukagesi, ngakho kwanele ukushiya indawo yezinto ezinikeza impendulo engalungile kazibuthe.

Esikhundleni sensimbi ye-homogeneous, izintambo eziningi zensimbi ezincanyana ezihlelwe ngendlela yegridi ye-cubic zinamathiselwe epuleti lezinto zokuvikela. Ngokushintsha ububanzi bezintambo kanye nebanga eliphakathi kwazo, kungenzeka ukulungisa amanani wemvamisa lapho isakhiwo sizoba nokungena kahle kukagesi. Ukuze uthole ukungasebenzi kahle kazibuthe esimweni esilula, umklamo uqukethe izindandatho ezimbili eziphukile ezenziwe ngomqhubi omuhle (isibonelo, igolide, isiliva noma ithusi) futhi ihlukaniswe ungqimba wenye into.

Uhlelo olunjalo lubizwa ngokuthi i-split ring resonator - efushanisiwe njenge-SRR, kusukela esiNgisini. I-resonator yokuhlukanisa indandatho (6). Ngenxa yezikhala emasongweni kanye nebanga eliphakathi kwabo, ine-capacitance ethile, njenge-capacitor, futhi njengoba izindandatho zenziwe ngezinto eziqhutshwayo, nazo zine-inductance ethile, i.e. ikhono lokukhiqiza imisinga.

Izinguquko endaweni yamagnetic yangaphandle evela ku-electromagnetic wave zibangela ukuthi i-current igeleze emasongweni, futhi lokhu kwamanje kudala insimu kazibuthe. Kuvela ukuthi ngomklamo ofanelekile, inkambu kazibuthe eyenziwe uhlelo iqondiswe ngokuphambene nensimu yangaphandle. Lokhu kuphumela ekungeneni kazibuthe okunegethivu kwento equkethe izakhi ezinjalo. Ngokusetha amapharamitha wesistimu ye-metamaterial, umuntu angathola impendulo kazibuthe engalungile ebangeni elibanzi lamaza wamaza.

Isakhiwo se-meta

Iphupho labaklami liwukwakha isimiso lapho amagagasi ayezogeleza kahle azungeze into (7). Ngo-2008, ososayensi eNyuvesi yaseCalifornia, eBerkeley, ngokokuqala ngqa emlandweni, bakha izinto ezinezinhlangothi ezintathu ezinenkomba ye-refractive engalungile yokukhanya okubonakalayo nokuseduze kwe-infrared, ukugoba ukukhanya kubheke ohlangothini oluphambene nesiqondiso salo semvelo. Bakha i-metamaterial entsha ngokuhlanganisa isiliva ne-magnesium fluoride.

Bese isikwa ibe yi-matrix ehlanganisa izinaliti ezincane. Ukwenzeka kwe-refraction engalungile kubonwe kumaza wamaza we-1500 nm (eduze kwe-infrared). Ekuqaleni kuka-2010, u-Tolga Ergin we-Karlsruhe Institute of Technology kanye nozakwabo e-Imperial College London wadala. engabonakali ikhethini elikhanyayo. Abacwaningi basebenzise izinto ezitholakala emakethe.

Basebenzise amakristalu e-photonic abekwe phezulu ukuze amboze i-microscopic protrusion epuleti legolide. Ngakho i-metamaterial idalwe kusuka kumalensi akhethekile. Amalensi abhekene ne-hump epulatifeni atholakala ngendlela yokuthi, ngokuphambukisa ingxenye yamaza okukhanya, aqede ukuhlakazeka kokukhanya eqhumeni. Ngokubheka ipuleti ngesibonakhulu, besebenzisa ukukhanya okunobude beza obuseduze nokukhanya okubonakalayo, ososayensi babona ipuleti eliyisicaba.

Kamuva, abacwaningi abavela eDuke University nase-Imperial College London bakwazi ukuthola ukubonakaliswa okungekuhle kwemisebe ye-microwave. Ukuze uthole lo mphumela, izakhi zomuntu ngamunye zesakhiwo se-metamaterial kufanele zibe ngaphansi kobude begagasi lokukhanya. Ngakho-ke kuyinselelo yobuchwepheshe edinga ukukhiqizwa kwezakhiwo ezincane kakhulu ze-metamaterial ezifana nobude begagasi lokukhanya okufanele zibuphendukise.

Ukukhanya okubonakalayo (violet kuya kokubomvu) kunobude obungamaza angama-380 kuya ku-780 nanometer (i-nanometer iyingxenye yesigidigidi semitha). Izazi zeNanotechnology zaseScottish University of St. Andrews zasiza. Bathole isendlalelo esisodwa se-metamaterial eminyene ngokwedlulele. Amakhasi e-New Journal of Physics achaza i-metaflex ekwazi ukugoba ubude beza obungama-nanometers angaba ngu-620 (ukukhanya okubomvu okuwolintshi).

Ngo-2012, iqembu labacwaningi baseMelika eNyuvesi yaseTexas e-Austin leza neqhinga elihluke ngokuphelele lisebenzisa ama-microwave. Isilinda esinobubanzi obuyi-18 cm sasimbozwe ngezinto ezingezinhle ze-plasma, ezivumela ukuxhashazwa kwezakhiwo. Uma inezinto ezibonakalayo eziphambene nalokho ezifihliwe, idala uhlobo "lwe-negative".

Ngakho, amagagasi amabili ayadlulana futhi into ingabonakali. Njengomphumela, okokusebenza kungagoba izigaba eziningana ezihlukene zefrikhwensi yegagasi ukuze ligeleze lizungeze into, lihlangane ngakolunye uhlangothi lwayo, okungenzeka lungabonakali kumuntu obukele ngaphandle. Imiqondo ethiyori iyaphindaphindeka.

Cishe ezinyangeni eziyishumi nambili ezedlule, i-Advanced Optical Materials yashicilela i-athikili mayelana nocwaningo olungase lube yisisekelo olwenziwe ngososayensi eNyuvesi yaseCentral Florida. Kwazi bani uma behlulekile ukunqoba imikhawulo ekhona "izigqoko ezingabonakali» Yakhiwe nge-metamatadium. Ngokolwazi abalushicilele, ukunyamalala kwento ebangeni lokukhanya elibonakalayo kungenzeka.

7. Izindlela zethiyori zokugoba ukukhanya entweni engabonakali

U-Debashis Chanda kanye nethimba lakhe bachaza ukusetshenziswa kwe-metamaterial enesakhiwo esinezinhlangothi ezintathu. Kwakungenzeka ukuyithola ngenxa yalokho okuthiwa. ukuphrinta kwe-nanotransfer (NTP), okukhiqiza amateyipu ensimbi-dielectric. Inkomba ye-refractive ingashintshwa ngezindlela ze-nanoengineering. Indlela yokusabalalisa ukukhanya kufanele ilawulwe esakhiweni sobuso obunezinhlangothi ezintathu sezinto kusetshenziswa indlela ye-electromagnetic resonance.

Ososayensi baqaphe kakhulu eziphethweni zabo, kodwa encazelweni yobuchwepheshe babo kucace bha ukuthi ukumbozwa kwento enjalo kuyakwazi ukuphambukisa amagagasi kagesi ngezinga elikhulu. Ngaphezu kwalokho, indlela izinto ezintsha ezitholakala ngayo ivumela ukukhiqizwa kwezindawo ezinkulu, okuholele ekutheni abanye baphuphe ama-fighters ambozwe ngale ndlela yokucasha ezobahlinzeka. ukungabonakali ephelele, kusukela ku-radar kuze kube semini.

Amadivaysi okufihla asebenzisa ama-metamatadium noma amasu optical awabangeli ukunyamalala kwangempela kwezinto, kodwa kuphela ukungabonakali kwabo kumathuluzi okuthola, futhi maduzane, mhlawumbe, emehlweni. Nokho, sekuvele kunemibono eqinile. U-Jeng Yi Lee no-Ray-Kuang Lee abavela eNyuvesi ye-National Taiwan Tsing Hua bahlongoze umqondo wethiyori we-quantum "cap of invisibility" engasusa izinto hhayi kuphela emkhakheni wokubuka, kodwa futhi kusukela eqinisweni lonke.

Lokhu kuzosebenza ngokufana nalokhu okuxoxwe ngakho ngenhla, kodwa kuzosetshenziswa isibalo sikaSchrödinger esikhundleni sezibalo zikaMaxwell. Iphuzu liwukwelula inkambu yamathuba ento ukuze ilingane noziro. Ngokwethiyori, lokhu kungenzeka ku-microscale. Kodwa-ke, kuzothatha isikhathi eside ukulinda amathuba ezobuchwepheshe okukhiqiza isembozo esinjalo. Njenganoma yini"ukungabonakali cap“Okungashiwo ukuthi kukhona abesifihlela kona ngempela.