Peb puas yuav paub txhua lub xeev ntawm teeb meem? Hloov peb, tsib puas
Xyoo tas los, cov xov xwm tshaj tawm cov ntaub ntawv hais tias "ib hom teeb meem tau tshwm sim," uas tuaj yeem hu ua superhard lossis, piv txwv li, yooj yim dua, txawm tias tsawg dua Polish, superhard. Los ntawm lub chaw soj nstuam ntawm cov kws tshawb fawb ntawm Massachusetts lub koom haum thev naus laus zis, nws yog ib hom kev tsis sib haum xeeb uas sib txuas cov khoom ntawm cov khib nyiab thiab superfluids - i.e. kua nrog xoom viscosity.
Cov kws tshawb fawb yav dhau los tau kwv yees qhov muaj nyob ntawm supernatant, tab sis tam sim no tsis muaj dab tsi zoo sib xws tau pom hauv chav kuaj. Cov txiaj ntsig ntawm kev tshawb fawb los ntawm cov kws tshawb fawb ntawm Massachusetts Institute of Technology tau luam tawm hauv phau ntawv journal Nature.
"Ib yam khoom uas ua ke nrog superfluidity thiab cov khoom muaj zog tiv thaiv kev nkag siab zoo," pab pawg thawj coj Wolfgang Ketterle, tus xibfwb ntawm physics ntawm MIT thiab 2001 Nobel nqi zog, tau sau rau hauv daim ntawv.
Txhawm rau kom nkag siab txog qhov tsis sib xws ntawm qhov teeb meem no, Ketterle pab pawg tau tswj hwm cov lus tsa suab ntawm atoms hauv lub xeev supersolid hauv lwm hom teeb meem hu ua Bose-Einstein condensate (BEC). Ketterle yog ib tus neeg nrhiav pom ntawm BEC, uas tau txais nws qhov Nobel nqi zog hauv Physics.
"Qhov kev sib tw yog ntxiv ib yam dab tsi rau lub condensate uas yuav ua rau nws hloov mus rau hauv daim ntawv sab nraud ntawm 'atomic ntxiab' thiab tau txais cov yam ntxwv ntawm cov khoom, "Ketterle piav qhia.
Pab pawg tshawb fawb tau siv cov kab teeb ci laser hauv lub tshuab nqus tsev ultra-siab los tswj kev txav ntawm cov atoms hauv condensate. Thawj txheej ntawm lasers tau siv los hloov ib nrab ntawm BEC atoms mus rau qhov sib txawv spin lossis quantum theem. Yog li, ob hom BECs tau tsim. Kev hloov ntawm atoms ntawm ob lub condensates nrog kev pab los ntawm cov kab teeb laser ntxiv ua rau muaj kev hloov pauv.
Ketterle tau hais tias "Ntxiv cov lasers tau muab cov atoms nrog lub zog ntxiv rau kev sib txuas ntawm lub voj voog sib txuas," Ketterle tau hais. Cov khoom uas tshwm sim, raws li kev kwv yees ntawm physicists, yuav tsum yog "superhard", txij li thaum condensates nrog conjugated atoms nyob rau hauv ib tug spin orbit yuav characterized los ntawm spontaneous "density modulation". Hauv lwm lo lus, qhov ntom ntawm cov teeb meem yuav tsum tsis tu ncua. Hloov chaw, nws yuav muaj cov qauv theem zoo ib yam li cov khoom siv crystalline.
Kev tshawb fawb ntxiv rau hauv cov ntaub ntawv superhard yuav ua rau kom nkag siab zoo dua ntawm cov khoom ntawm superfluids thiab superconductors, uas yuav yog qhov tseem ceeb rau kev hloov hluav taws xob zoo. Superhards kuj tseem yog tus yuam sij rau kev tsim cov hlau nplaum zoo dua thiab cov sensors.
Tsis yog lub xeev ntawm aggregation, tab sis theem
Puas yog lub xeev superhard yog ib yam khoom? Cov lus teb muab los ntawm niaj hnub physics tsis yog li ntawd yooj yim. Peb nco ntsoov los ntawm tsev kawm ntawv tias lub cev lub cev ntawm cov teeb meem yog daim ntawv tseem ceeb uas cov khoom nyob rau hauv thiab txiav txim siab nws cov yam ntxwv ntawm lub cev. Cov khoom ntawm ib yam khoom yog txiav txim los ntawm kev npaj thiab tus cwj pwm ntawm nws cov molecules constituent. Cov kev faib ib txwm muaj ntawm cov xeev ntawm cov teeb meem ntawm lub xyoo pua XNUMXth txawv peb lub xeev: khoom (khoom), kua (kua) thiab gaseous (gas).
Txawm li cas los xij, tam sim no, theem ntawm cov teeb meem zoo li yog qhov tseeb dua txhais ntawm cov qauv ntawm qhov muaj teeb meem. Cov khoom ntawm lub cev nyob rau hauv ib lub xeev nyob ntawm seb qhov kev npaj ntawm cov molecules (los yog atoms) uas lub cev yog tsim. Los ntawm qhov kev xav no, kev faib qub rau hauv xeev ntawm kev sib sau ua ke tsuas yog muaj tseeb rau qee yam khoom, txij li kev tshawb fawb tshawb fawb tau pom tias qhov uas yav tas los suav tias yog ib lub xeev ntawm kev sib sau ua ke tuaj yeem muab faib ua ntau theem ntawm cov khoom sib txawv. particle configuration. Muaj txawm tias muaj xwm txheej thaum molecules nyob rau tib lub cev tuaj yeem npaj sib txawv tib lub sijhawm.
Tsis tas li ntawd, nws tau muab tawm tias cov khoom muaj zog thiab cov kua hauv lub xeev tuaj yeem pom tau hauv ntau txoj hauv kev. Tus naj npawb ntawm cov theem ntawm cov teeb meem nyob rau hauv lub system thiab tus naj npawb ntawm intensive variables (piv txwv li, siab, kub) uas yuav hloov tau yam tsis muaj ib tug zoo hloov nyob rau hauv lub system yog piav los ntawm lub Gibbs theem txoj cai.
Ib qho kev hloov hauv theem ntawm cov khoom yuav xav tau cov khoom siv lossis kev txais lub zog - tom qab ntawd tus nqi ntawm lub zog ntws tawm yuav yog proportional rau qhov loj ntawm cov khoom uas hloov cov theem. Txawm li cas los xij, qee qhov kev hloov pauv tau tshwm sim yam tsis muaj lub zog nkag los yog tso tawm. Peb kos ib qho kev txiav txim siab txog cov theem hloov ntawm lub hauv paus ntawm ib kauj ruam hloov hauv qee qhov ntau uas piav txog lub cev no.
Hauv qhov kev faib tawm ntau tshaj plaws uas luam tawm rau hnub tim, muaj txog tsib puas lub xeev. Ntau yam tshuaj, tshwj xeeb tshaj yog cov sib xyaw ntawm cov tshuaj sib txawv, tuaj yeem tshwm sim ib txhij hauv ob lossis ntau theem.
Niaj hnub nimno physics feem ntau lees txais ob theem - kua thiab khoom - nrog rau theem roj yog ib kis ntawm cov kua theem. Cov tom kawg suav nrog ntau hom ntshav plasma, theem uas twb tau hais txog supercurrent, thiab ntau lub xeev ntawm cov teeb meem. Cov theem khoom yog sawv cev los ntawm ntau cov ntaub ntawv crystalline, nrog rau daim ntawv amorphous.
Topological tshuaj
Cov ntawv ceeb toom ntawm "cov xeev sib sau ua ke" tshiab lossis nyuaj-rau-txhais cov theem ntawm cov ntaub ntawv tau ua ib ntus ntawm cov xov xwm tshawb fawb nyob rau xyoo tas los no. Nyob rau tib lub sijhawm, muab cov kev tshawb pom tshiab rau ib qho ntawm pawg tsis yog ib txwm yooj yim. Cov tshuaj supersolid tau piav qhia ua ntej yog tej zaum yog ib theem khoom, tab sis tej zaum physicists muaj kev xav txawv. Ob peb xyoos dhau los hauv ib lub tsev kawm ntawv kuaj sim
Nyob rau hauv Colorado, piv txwv li, ib tug dropleton tau tsim los ntawm cov khoom ntawm gallium arsenide - ib yam kua, ib yam khoom. Nyob rau hauv 2015, ib pab neeg thoob ntiaj teb ntawm cov kws tshawb fawb coj los ntawm chemist Cosmas Prasides ntawm Tohoku University hauv Nyij Pooj tau tshaj tawm qhov kev tshawb pom ntawm lub xeev tshiab ntawm cov teeb meem uas sib txuas cov khoom ntawm insulator, superconductor, hlau, thiab hlau nplaum, hu ua Jahn-Teller hlau.
Kuj tseem muaj atypical "hybrid" xeev ntawm kev sib sau. Piv txwv li, iav tsis muaj cov qauv crystalline thiab yog li qee zaum muab faib ua "supercooled" kua. Tom ntej no yog cov kua siv lead ua kua, siv rau hauv qee qhov kev qhia; putty - silicone polymer, yas, elastic los yog nkig, nyob ntawm seb tus nqi ntawm deformation; super nplaum, nws tus kheej ntws kua (ib zaug pib, cov dej ntws mus ntxiv kom txog thaum cov kua hauv lub khob sab saum toj tas lawm); Nitinol, npib tsib xee-titanium alloy nrog lub cim xeeb - thaum khoov, nws yuav ncaj rau hauv cov kwj ntawm huab cua sov lossis hauv cov kua.
Kev faib tawm yog nce zuj zus. Cov thev naus laus zis niaj hnub no ua rau pom kev ciam teb ntawm cov xwm txheej. Kev tshawb pom tshiab tau raug ua. 2016 Nobel Prize winners - David J. Thouless, F. Duncan, M. Haldane thiab J. Michael Kosterlitz - txuas ob lub ntiaj teb: teeb meem, uas yog kev kawm ntawm physics, thiab topology, uas yog ib ceg ntawm kev ua lej. Lawv pom tau hais tias muaj cov kev hloov pauv uas tsis yog ib txwm muaj cuam tshuam nrog cov teeb meem topological thiab cov theem tsis zoo ntawm cov teeb meem - cov theem topological. Qhov no ua rau muaj kev kub ntxhov ntawm kev sim thiab kev ua haujlwm theoretical. Lub avalanche no tseem ntws nrawm heev.
Qee cov neeg rov pom XNUMXD cov ntaub ntawv ua ib qho tshiab, tshwj xeeb hauv lub xeev. Peb tau paub hom nanonetwork no - phosphate, stanene, borophene, los yog, thaum kawg, nrov graphene - tau ntau xyoo. Cov neeg tau txais txiaj ntsig Nobel tau hais los saum toj no tau koom nrog, tshwj xeeb, hauv kev tshuaj xyuas topological ntawm cov ntaub ntawv ib txheej.
Cov kev tshawb fawb qub ntawm cov xeev ntawm cov teeb meem thiab theem ntawm cov teeb meem zoo li tau los ntev. Tshaj dhau qhov peb tseem tuaj yeem nco tau los ntawm cov lus qhia physics.
