MEKhANIKAI KVANTI

MEKhANIKAI KVANTI (mekhanikai mavji), nazariyaest, ki tariqi tavsif va qonuniyathoi harakati mikrozarrahoro dar maydoni berunai fiziki muqarrar mekunad; yake az faslhoi nazariyai kvantist. Mahz Mekhanikai kvanti bud, ki zimni tavsif dodani sokhti atom no sirishti fizikii spektrhoi onhoro muqarrar kardaast, tabiati bandi khimiyaviro oshkor sokhtaast, sistemai davrii Mendelsevro tafsifu tavzeh namudaast va g.

Qonunhoi Mekhanikai kvanti asosi omuzishi sokhti modda meboshad. Dar zaminai onho sokhti atom omukhta meshavad, tabiati bandhoi khimiyavi muqarrar megardad, sistemai davrii elementho tabir meyobad, sokhti yadroi atomho manidod meshavad, khosiyati zarpahoi elementari mavridi tadqiqu omuzish qaror megirad. Azbaski khosiyati qismhoi makroskopi az rui harakat va tasiri mutaqobili zarrahoi tarkibii onho muayyan karda meshavand, qonunhoi Mekhanikai kvanti baroi fahmidani aksari hodisahoi makroskopi asos meyoband. Mas., bo yorii M. k. vobastagii garmigunjoish ba harorat va hisob kardani buzurgii garmigujuoishi gazu jismhoi sakht manidod karda shudand, sokht va bisyor khosiyathoi jismhoi sakht (metallho, dielektrho, nimnoqilho) sharqu tabir yoftand. Faqat dar zaminai Mekhanikai kvanti aniqu daqiq sharh dodani hodisahoi ferromagnetizm, favquljorishavi va favqunnoqiliyat, fahmidani tabiati fizikii rezasitorahoi safed va sitorahoi neytroni, nihoyat oshkor namudani mekhanizmi jorishavii reaksiyai termoyadroi dar Oftobu sitoraad muyassar shud.

Yak qator komyobihoi kalontarini tekhnikai asri 20 mohiyatan ba qonunhoi khosi Mekhanikai kvanti asos yoftaand. Chunonchi, kori reaktori yadroi ba qonunhoi mekhanikai kvanti asos yoftaast; olimon inchunin rohhoi dar laboratoriya ba amal barovardani reaksiyahoi termoyadroiro dar zimni in qonunho tadqiq karda istodaand. Gayr az in yak qator hodisahoi fizikiero ki dar metallhovu nimnoqilho (onho dar tekhnikai navtarin istifoda meshavand) ruy medihand, berun az Mekhanikai kvanti manidod kardan mumkin nest. Guftan kofist, ki bunyodi nazarii elektronikai kvanti barin sohai muhimu taraqqikardaistodai fizikayu tekhnikaro nazariyai kvantai afkanishot tashkil medihad. Qonunhoi Mekhanikai kvantiro hamchunin hangomi justuju va sokhtusozi masolehi nav (alalkhusus, masolehi magniti, nimnoqili va favqunnoqil) istifoda mebarand. Ba hamin tariq, Mekhanikai kvanti to darajai muayyan ilmi «tekhniki» meboshad va omukhtani on na tanho baroi fizikhoi muhaqqiq, balki baroi injeneron niz zarur ast.

Goyai asosii Mekhanikai kvanti on ast, ki har yak zarra (elektron, yadro, atom, molekula va g.) ham ba khosiyathoi korpuskulavi va ham ba khosiyathoi mavji sohib ast, yane dualizmi korpuskulavi mavji joy dorad. In khususiyati umumi bo sobitai Plank (h 6,626 10—54 J.son) ifoda karda meshavad. Dar tashakkul va ravnaqi M. k. tadqiqothoi M. Plank, N. Bor, L. de-Broyl, 9. Shryodinger, V. Geyzenberg, P. Dirak, M. Born, V. Fok, Erenfest barin olimon masomi buzurg dorad.

Olimon qonunhoi fizikai klassikiro hangomi ba harakati zarrahoi massaashon nihoyat khurd tatbiq namudan ba khulosa omadand, ki tasavvurothoi peshinai fiziki ba kor nameoyand. Dar voqe, muvofiqi in tasavvurot energiyai shuoafkanii zarra muttasil tagyir yofta metavonad. Va hol on ki dar olami mikrozarraho in tavr nest. Chunon ki M. Plank (1909) oshkor kardeast, nurafkani faqat ba qimathoi munfasil (kvantonida) sohib buda, evergiyai har yak afkanishi judogonae = Av meboshad (v — basomadi mavji elektromagnitii khorid 8 furuburd). Yane har yak zarra kandanandae reza-reza (rezai afkanishotro kvant menomand) shuo meafkanad va shuo furu mebarad.

L. Eynshteyn goyai Plankro inkishof doda, nishon dod, ki diskreti (reza-reza) budani nurafkani az khudi tabnati afkanishoti elektromagniti barmeoyad. Afkanishoti elektromagniti (az jumla nuri rushnoi) az chunin kvantho — ba istiloh fotonho «iborat» ast. N. Bor nazariyai kvantii rushnoiro ba problemai sokhti atom tatbiq namuda (1913) nishon dod, ki elektronhoi atom dar girdi yadroi on az rui madorhoe charkh mezanand, ki ba qonunhoi mekhanikai klassiki itoat namekunand. Dar har yaki in madorho elektron dar holati muayyani energetiki, dar holati stasionari meboshad; atom faqat dar vaqti az yak mador ba madori dig. guzashtani elektronho shuo meafkanad yo furu mebarad. Energiyai afkanish bo formulai h\iK = — ej ifoda meshavad. Nazariyai Bor khosiyathoi shuoafkanii atomi soddatarin — a tomi gidrogenro sharh dod, ammo onro ba atomu molekulahoi murakkab tatbiq kardan mumkin nashud. Soli 1924 L. de-Broyl pai manidodi fizikii takhminoti Bor kushida, dar bobati ba hamai navhoi materiya khos budani dualizmi korpuskulaviyu mandifaravi peshnihod kard. Muvofiqi adadii u, har yak zarrai modda, sarfi nazar az sirishti fizikii vay, dar barobari khosiyati korpuskulavi khosiyati mandi niz dorad. Darozii mavj (X) va impulsi zarrai mazkur (r) boshad, az rui formulai asrii aloqamandand: A

Khosiyathoi mandii zarraho meboist dar hodisahoi difraksioni zohir meshud. Dar haqiqat ham soli 1927 K. Devisson va L. fermer bori nakhust difraksiyai elektronhoro mushohida kardand va bo hama in aqidai de-Broylro dar tajriba isbot namudand. s. 1926 E. Shryodinger muodilaero tahiya kard, ki raftori «mavj»-hoi de-Broylro dar maydoni quvvagii beruna tavsif mekard. Ana hamin tavr, mekhanikai mandi nom sohai fizikai nazari tashakkul, yoft, Muodilai stasionarii (az vaqt novobasta) Shryodangerro, ki az jumlai muodilahoi asosii Mekhanikai kvanti hisob meshavad, ba shakli zerin menavisand:

Dar in jo  — funksiyai mandi; E — energiyai zarrai massaash m; V(x)— energiyai potensialii maydoni berunai stasionari (nig. niz Muodilai Shryodinger).

Garchande durustii muodilai Shryodanger dar tajriba isbot shud, ammo dar bobi manidodi fiziki funksiyai mandi dar bayni fizikho bahsu munozirahoi domanadore ba amal omad. M. Born (1927) bori nakhust manidodi statistii funksiyai mandiro peshnihod kard. Manoi statistii funksiyai mandi, yane ehtimoli dar yagon vohidi hajm mavjud budani zarra bo kvadrati moduli, funksiyai mandi ifoda meyobad. Pas, dar Mekhanikai kvanti dar yak vaqt ham impuls va ham koordinatai zarraro aniq muayyan kardan imkoniopazir meboshad; in az tanosubi nomuayyani barmeoyad, ki onro Geyzenberg (1927) muqarrar kardaast. Dinamikai sistemai kvanti, yane bo mururi zamon tagyir yoftani holati vay, dar zimni muodilai stasionarii Shryodanger tavsifnopazir ast. Baroi halli in masala ba muodilai umumii Shryodinger ru ovardan lozim ast, ki ba in shakl navishta meshavad:

In muodila, ki onro dar Mekhanikai kvanti muodilai harakat menomand, dar surati az vaqt vobasta budani energiyai potensiali [K = (kh, ()] niz istifoda burdan mumkin ast. Az in muodila istifoda burda, baroi vaqthoi gunogun (t) funksiyai mandi Ch^kh, u, g, 0~ro muayyan kardan mumkin ast. Pas, agar holati avvalai sistemai kvanti malum boshad holathoi badinai vayro ham yoftan mumkin megardad. Ba in mani dar Mekhanikai kvanti prinsipi sababiyat yake az qonunhoi asosi ba hisob meravad.

Dar Mekhanikai kvanti buzurgihoi fiziki va vobastagii bayni onho ba vositai operatorho ifoda meyoband. Yak qator qimathoi yagon buzurgiro slektri hamon buzurgi menomand. Dar Mekhanikai kvanti muodilai asosii sistemae, ki holatash bo mururi vaqt tagyir meyobad.

chunin ast: (p = Ya^, dar in jo operatori N gamiltonian nom dorad. Agar sistema dar tahti tasiri maydoni potensiali boshad, ni muodila namudi muodilai umumii Shryodingerro megirad.

Dar atrofi prinsipho, mafhumhoi umumi va qonunhoi asosii Mekhanikai kvanti hanuz ham bahsu munozirahoi falsafi idoma dorand, ki in hargiz besabab nest. Mekhanikai kvanti yake az komyobihoi benaziri ilmi muosir ba hisob meravad. Ba tufayli Mekhanikai kvanti zarra, mavj, harakat, holat, sababiyat barin mafhumotu tasavvuroti fizikai klassiki ba kulli tagyir yoftand.

Ad.: Blokhinsev D. I. Osnovi kvantovoy mekhaniki, 5 nas., M., 1976; Landau L. D., L i f sh i s E. M., Kvantovaya mekhanika, 3 izd., M., 1976 (Teoreticheskaya fizika t. 3); Feynman R.. Leyton R., Svnds M., Feynmanovskie leksii po fizike, per. s angl., vip. 8—9, M., 1977—78.

A. Ashurov, Sh. Shakirov.