Ukuphixana kohoyana
Ukuphixana kohoyana yisimongotho seqembu lezinhlayiyana eziphehlwayo, ezinananayo, noma ezihlanganyela ukusondelana ngendawo ngendlela eyenza ubunjalo bohoyana benhlayiyana ngayinye yeqembu bungachaziseki ngokuhlukile kubunjalo bezinye, kuhlanganisa nalapho izinhlayiyana zihlukaniswe ngebanga elikhulu. Isihloko sokuphixana kohoyana sisekujuleni komehluko phakathi komchazandalo omdala nomchazandalo wohoyana: ukuphixana kuyisici esiyinhloko sokuguxaza kohoyana esingatholakali kwezokuguxazela ezindala.
Izilinganiso zezigubo zoqobo ezifana nesikhundla, umjijeyane, ukumpimpiliz nokuluthuzeka okwenziwa izinhlayiyana eziphixene, kwezinye izimo, kulula ukuthola ukuthi zihlobene. Ngokwesibonelo, uma umbhangqwana wezinhlayiyana ziphehlwa ngendlela eyenza ukumpimpiliza kwazo sibe ize, futhi inhlayiyana eyodwa kutholakala ukuthi impimpiliza ishwilelemuva (clockwise) ngamachopho wokuqala, khona ukumpimpiliza kwenhlayiyana yesibili, lapho kulinganiswa ngamachopho afanayo, kuzoshwilelaphoko (anticlockwise). Lokhu kucondoza kuletha imithelela eyinkiyankiya.
Lesi simongotho kwakuyisihlokondaba sephepha langowe-1935 lika-Albert Einstein, uBoris Podolsky, noNathan Rosen, namaphepha kaErwin Schrödinger kamuva. UEinstein wafunga ukuthi lokhu kucondoza akunakwenzeka, futhi kwephula imithetho yembangela futhi waphika wathi umbono wamukelwe wokuguxazela kohoyana kusho ukuthi awuphelele.