Ib txoj kev tshawb nrhiav tshiab uas coj los ntawm cov kws tshawb fawb ntawm University of Chicago thiab Argonne National Laboratory tau txheeb xyuas cov txheej txheem microscopic uas cov pob zeb diamond nto cuam tshuam rau quantum coherence ntawm nitrogen-vacancy (NV) centres- tsis xws luag hauv pob zeb diamond uas underpin qee qhov niaj hnub no quantum sensors. Txoj kev tshawb no tau tshwm sim hauvCov ntaub ntawv txheeb xyuas lub cevthiab tau raug xaiv los ua Cov Ntawv Qhia Cov Lus Qhia.
Giulia Galli, tus xibfwb ntawm University of Chicago Pritzker Lub Tsev Kawm Ntawv ntawm Molecular Engineering (Uchicago PME) thiab tus kws tshawb fawb laus ntawm Argonne National Laboratory tau hais tias "Ib qhov kev sib tw ntev ntev tau nkag siab tias vim li cas cov chaw ntiav NV poob kev sib koom ua ke sai heev. "Los ntawm kev sib txuas ua ntej- cov qauv ntog qauv nrog quantum dynamics simulations, peb nkag siab tias qhov ua txhaum ntawm decoherence tsis yog qhov uas spin nyob rau ntawm pob zeb diamond nto, tab sis yuav ua li cas lawv txav: nto suab nrov yog dynamical."
Cov kev tshawb pom ntawm txoj kev tshawb fawb qhia meej, physics -raws li cov lus qhia rau engineering pob zeb diamond nto uas pab khaws cia quantum coherence, ib qho tseem ceeb yuav tsum tau rau quantum sensing thiab quantum ntaub ntawv technologies.
NV cov chaw yog atomic- nplai qhov tsis xws luag hauv pob zeb diamond uas nws lub xeev quantum spin tuaj yeem pib, tswj tau, thiab nyeem tawm qhov pom ntawm chav tsev kub. Thaum muab tso rau ze rau ntawm pob zeb diamond nto, NV cov chaw tuaj yeem ntes cov hlau nplaum thiab hluav taws xob tsis muaj zog los ntawm cov khoom siv, cov khoom siv, thiab cov kab mob lom. Txawm li cas los xij, qhov sib thooj no tseem nthuav tawm lawv mus rau saum npoo - lub suab nrov, xws li hloov pauv qhov tsis xws luag thiab kev them nqi lossis hluav taws xob- suab nrov, uas ua rau lawv cov quantum coherence sai thiab txwv kev ua haujlwm ntawm lub sensor.
"Hauv cov ntaub ntawv, lub hauv paus pib ntawm lub suab nrov nrov feem ntau hu ua 'X spin' los yog ' tsaus nti spin,' vim hais tias qhov tseeb microscopic xwm ntawm lub suab tsis to taub, thiab nws tej zaum yuav stems los ntawm optically inactive sites," said UChicago PME Ph.D. Tus neeg sib tw Jonah Nagura, tus thawj coj ntawm txoj kev tshawb no. "Peb txoj kev tshawb fawb pab txheeb xyuas qhov tsis zoo ntawm qhov chaw thiab teeb tsa txoj hauv kev rau kev tshem tawm cov suab nrov kom ib tus tuaj yeem tsim ntau dua, muaj zog quantum sensors."
In this work, the researchers combined density functional theory-based atomistic models of diamond surfaces with advanced quantum decoherence simulations to identify and isolate the dominant surface noise mechanisms.
Nagura tau hais tias "thaum lub sijhawm tsim cov txheej txheem ntawm pob zeb diamond nto rau kev paub txog daim ntawv thov, qhov tsis zoo ntawm qhov chaw yuav raug tsim, suav nrog qhov peb hu ua dangling bonds," Nagura tau hais. "Qee qhov tsis xws luag tuaj yeem tuav cov khoom siv hluav taws xob tsis sib xws, paramagnetic spins uas hloov pauv lub sijhawm thiab tsim cov suab nrov sib nqus uas cuam tshuam rau NV chaw.
Txoj kev tshawb no qhia tau hais tias txoj kev ntawm qhov chaw raug tshem tawm, muaj kev cuam tshuam loj heev rau NV coherence. Nagura qhov kev xam pom tau pom tias cov pa oxygen- thiab nitrogen- tshem tawm qhov chaw feem ntau khaws cia ze ntawm - kev sib koom ua ke ntau txawm rau NV cov chaw tsuas yog ob peb nanometers hauv qab ntawm qhov chaw. Los ntawm qhov sib txawv, hydrogen- thiab fluorine-tawm qhov chaw nthuav tawm ntau qhov chaw muaj zog dua- hais txog cov suab nrov sib nqus, uas ua rau luv luv lub sij hawm coherence.
"Txawm li cas los xij, thaum txiav tawm chemistry thiab kev taw qhia facet tseem ceeb, peb pom tias nws yog qhov chaw -electron so thiab hopping uas yog tus thawj coj ntawm kev sib koom ua ke ntawm ntiav NVs," Nagura tau hais.
"Lub tshuab hluav taws xob tam sim no nyob rau ntawm qhov chaw cuam tshuam nrog tib lub laser pulses uas siv los tswj thiab nyeem tawm ntawm NV chaw. Lub teeb laser tuaj yeem tsav cov kev hloov pauv hauv lub xeev tus nqi, ua rau cov hluav taws xob tsis sib xws kom plam ntawm qhov sib txawv atomic. Cov lus tsa suab no ua rau lub sijhawm ntxiv - sib txawv magnetic teb uas ua rau muaj suab nrov ntxiv."
Los ntawm kev txheeb xyuas cov suab nrov nrov microscopic channel, txoj kev tshawb no muab ib txoj hauv kev rau kev txhim kho NV- raws li quantum li, nrog rau qhov cuam tshuam ncaj qha rau quantum sensing thiab cov ntaub ntawv ua.
Nagura tau hais tias "Ib zaug peb suav txog kev txav hluav taws xob ntawm qhov chaw, kev xav thiab kev sim thaum kawg," Nagura hais.
