Tsis ntev los no, cov kws tshawb fawb txawv teb chaws tau ua tiav ib qho tshiablaser txiasthiab cov txheej txheem xa khoom uas compresses ntau ntawm cov molecules rau hauv qhov chaw kaw thaum tswj supercooling.
Justin Burau, tus kws tshawb fawb ntawm University of Colorado ntawm Boulder, Tebchaws Asmeskas, tau txias ib pawg ntawm cov molecules kom qis dua Doppler kub los ntawm kev siv lub cuab yeej magneto-optical.
Kev txias huab cua molecular rau quantum degeneracy yuav tsum muaj txheej txheem uas muaj ntau theem. Ua ntej, cov huab cua molecular raug kaw thiab laser-txias rau kaum ntawm μK hauv lub magneto-optical trap (MOT), qhov twg peb khub ntawm counter-propagating laser beams converge ntawm xoom point ntawm lub quadrupole magnetic teb. Cov pawg molecular yog tom qab ntawd xa mus rau lub cuab (CT) rau kev cia, qhov twg evaporative txias tuaj yeem txo lawv qhov kub mus rau kaum ntawm nK.
Qhov teeb meem nrog rau txoj hauv kev no yog tias cov lasers feem ntau siv rau molecular MOT yog "liab detuned" nrog rau kev sib haum xeeb ntawm molecular resonance thiab tsis tuaj yeem poob qis dua Doppler txias txwv, yog li ua kom sov thiab diffuse molecular pawg. Yog li ntawd, tus naj npawb ntawm cov molecules hloov mus rau CT feem ntau yog tsawg heev.
Burau thiab nws cov npoj yaig siv cov txheej txheem hu ua "grey molasses cooling" kom txias yttrium oxide molecules. Cov txheej txheem siv lub xiav detuned laser tsav lub molecules mus rau ib tug "tsaus" hauv av xeev, qhov chaw uas lawv nres absorbing xwm txheej photons.
Thaum kawg, los ntawm kev siv lub teeb nrog ib qho tshwj xeeb polarization configuration thiab MOT's quadrupole teb, lawv ua tiav sub-Doppler txias thiab tsim ib txoj hauj lwm-dependent quab yuam uas compresses cov molecular pawg. Cov kws tshawb fawb hais tias qhov ntim compression no yuav pab txhim kho kev thauj mus los ntawm cov molecules rau hauv CT (tam sim no nws tsuas yog ob peb feem pua).
