Lidar Mai Ƙarfafa Quantum: Tsayayyar Auna Nisa Daga Garkuwar Al'ada

1. Gabatarwa & Bayyani

Wannan takarda ta gabatar da wani nunin gwaji mai ban mamaki na tsarin Lidar (Gano Haske da Auna Nisa) mai ƙarfafa quantum. Babban sabon abu shine tsayayyarsa a kan garkuwar al'ada da aka yi niyya—wata muhimmiyar rauni ga lidar na al'ada da ake amfani da shi a cikin motocin cin gashin kansu, sa ido, da zana taswira. Tsarin yana amfani da tushen nau'i-nau'i na haske mai ci gaba da bugawa da kuma bincike mai zurfi na ƙididdiga don samun gano manufa tare da ƙarancin haske mai nuni har zuwa -52 dB kuma yana kiyaye aiki a cikin babban amo na baya.

Aikin ya cika gibin tsakanin fa'idar quantum na ka'idar da fasahar hankali mai aiwatarwa, yana motsawa fiye da yanayin dakin gwaji da aka sarrafa don magance yanayin adawa na ainihi.

2. Ka'idoji na Tsakiya & Hanyoyin Aiki

2.1 Tsarin Hasashen Quantum

Ba kamar lidar na al'ada ba wanda ke amfani da ƙararrakin laser masu haske da daidaitawa, wannan tsarin ya dogara ne akan ka'idar Hasashen Quantum (QI). QI tana amfani da alaƙar quantum, musamman haɗin kai, tsakanin nau'i-nau'i na haske. Ana aika wani haske ("sigina") don bincika manufa, yayin da abokin tarayya ("mai zaman kansa") ake ajiye shi a cikin gida. Ko da hasken sigina mai dawowa ya nutsar da amo, alaƙarsa da mai zaman kansa tana ba da damar ƙin amo mai inganci sosai ta hanyar gano daidaituwa.

Matsakaicin fa'idar quantum na ka'idar don jihohin Gaussian yana iyakance a 6 dB fiye da mafi kyawun dabarun al'ada, kamar yadda S. Lloyd ya kafa kuma daga baya S. Guha da J. H. Shapiro suka gyara. Wannan aikin yana aiwatar da wani tsari mai amfani, mai samun ma'auni wanda ke kusanci wannan iyaka.

2.2 Tsarin Tsarin & Tushen Nau'i-nau'i na Haske

Tsarin gwajin ya ta'allaka ne akan tushen ci gaba da gudu (CW) na raguwar ƙima ta kwatsam (SPDC). Wannan yana haifar da nau'i-nau'i na haske masu alaƙa na lokaci. Amfani da tushen CW, sabanin bugun jini, yana sauƙaƙa tsarin kuma yana guje wa lokacin lokaci wanda mai garkuwa zai iya amfani da shi.

Muhimman Abubuwan:

Crystal SPDC: Yana haifar da nau'i-nau'i na haske masu haɗin kai (misali, sigina a 1550 nm, mai zaman kansa a 810 nm).
Na'urar Gano Shela: Tana gano hasken mai zaman kansa, "shela" kasancewar abokin tarayya na sigina.
Hanyar Manufa & Kayan Gani na Tattarawa: Yana aika hasken sigina zuwa manufa kuma yana tattara ƙarancin dawowa.
Na'urar Gano Sigina & Da'irar Daidaituwa: Yana auna hasken dawowa kuma yana gano daidaituwa tare da shela a cikin ƙaramin taga na lokaci ($\Delta \tau$).

3. Aiwal da Bincike na Fasaha

3.1 Tsarin Binciken Log-Likelihood

Ana siffanta aikin tsarin ta amfani da gwajin rabon log-likelihood (LLR), kayan aiki mai ƙarfi na ƙididdiga don gwajin hasashe. Wannan yana motsawa fiye da ƙidayar daidaituwa mai sauƙi.

Tushen Lissafi: Ga kowane rukunin lokacin gano, ana kwatanta hasashe guda biyu:

$H_0$: Babu manufa (amo na baya kawai ke nan).
$H_1$: Manufa tana nan (sigina + amo na baya).

Ana ƙididdige LLR, $\Lambda$, daga yuwuwar abubuwan gano da aka lura a ƙarƙashin kowane hasashe:

$\Lambda = \log\left(\frac{P(\text{bayanai} | H_1)}{P(\text{bayanai} | H_0)}\right)$

Ana yanke shawara ta hanyar kwatanta $\Lambda$ zuwa wani bakin kofa. Wannan tsarin yana bambanta sigina daga amo da kyau, yana haɓaka yuwuwar gano don wani ƙimar faɗuwar ƙarya (ma'aunin Neyman-Pearson).

3.2 Ka'idar Bin Diddigin Bayan Gida Mai Sauyi

Wani sabon abu mai mahimmanci shine sabuwar ka'ida don sarrafa garkuwar al'ada mai saurin jinkiri (misali, hasken yanayi mai saurin canzawa) yayin da yake ci gaba da kariya daga garkuwa mai sauri (misali, bugun amo da aka yi niyya don cika na'urar gano).

Ka'idar tana ƙididdige ƙimar hasken baya a ainihin lokaci ta hanyar nazarin rukunoni na lokaci inda ba a gano shela ba (don haka ba a sa ran sigina na gaske). Ana amfani da wannan ƙima don daidaita bakin kofa na LLR ko sigogin ƙira, yana "bin diddigin" canjin baya yadda ya kamata. Wannan yana kiyaye hankalin tsarin ba tare da makantar da shi ta hanyar jinkirin adawa ko canje-canjen muhalli ba.

4. Sakamakon Gwaji & Aiki

Ƙarancin Haske na Manufa

-52 dB

Mafi ƙarancin iya gano

Haɓaka SNR

30 dB

Sama da ma'aunin al'ada

Ƙudurin Sarari

11 cm

An iyakance ta girgizar na'urar gano

Sigina/Baya

> 10⁵:1

Rarrabe da aka yi aiki a ƙarƙashinsa

4.1 Haɓaka Sigina-zuwa-Amo

Tsarin ya nuna aiki tare da ƙarar baya sama da sau 100,000 mafi girma fiye da ƙimar dawowar sigina. Idan aka kwatanta da tsarin lidar na al'ada mai kyau ta amfani da matsakaicin adadin haske iri ɗaya, tsarin quantum ya ba da haɓaka har zuwa 30 dB a cikin rabo na sigina-zuwa-amo (SNR). A madadin, zai iya samun ƙimar kuskure iri ɗaya da tsarin al'ada sau 17 da sauri.

4.2 Gwaje-gwajen Tsayayya da Garkuwa

An sanya tsarin ga duka garkuwar al'ada mai jinkiri da mai sauri.

Garkuwa Mai Jinkiri: Ka'idar bin diddigin baya mai sauyi ta yi nasarar rama ƙarar hasken baya yana ƙara sannu a hankali, yana hana lalacewar aiki. Idan ba tare da wannan ka'ida ba, ƙimar faɗuwar ƙarya na tsarin da zai tashi sosai.
Garkuwa Mai Sauri: Dogaron tsarin na asali akan alaƙar lokaci a cikin ƙaramin taga na daidaituwa ($\sim$ns) ya sa ya zama mai kariya ta dabi'a ga bugun amo marasa alaƙa mai girma. Hasken mai garkuwa da wuya ya faɗi cikin taga na daidaituwa na ainihin lamarin shela.

4.3 Daidaiton Auna Nisa

Ya wuce gano kawai, tsarin ya yi auna nisa a cikin yanayin garkuwa. Ta hanyar auna jinkirin lokaci tsakanin shela da daidaituwar dawowar sigina, an ƙayyade nisa zuwa manufa tare da ƙudurin sarari na 11 cm. Wannan ƙudurin ya iyakance ta hanyar girgizar lokaci na na'urorin gano haske guda ɗaya, ba ta hanyar ka'idar quantum kanta ba, yana nuna wurin haɓakawa tare da mafi kyawun na'urori masu gano.

5. Tsarin Bincike & Misalin Lamari

Misalin Lamari: Bambanta Sigina daga Amo a cikin Rukunin Lokaci Guda

Yi la'akari da wani sauƙaƙan yanayi don kwatanta tsarin yanke shawara na log-likelihood. Yi zaton ƙarancin ƙidayar baya ($\lambda_b = 0.01$) da ɗan ƙaramin ƙidayar lokacin da manufa ta kasance ($\lambda_{s+b} = 0.02$), saboda ƙarancin sigina na quantum.

Lura: Na'urar gano ta yi rajistar ƙidayar haske ɗaya a cikin takamaiman rukunin lokaci.

Yuwuwar (ta amfani da ƙididdiga na Poisson):

$P(1 | H_0) = \lambda_b e^{-\lambda_b} \approx 0.0099$
$P(1 | H_1) = \lambda_{s+b} e^{-\lambda_{s+b}} \approx 0.0196$

Rabon Log-Likelihood: $\Lambda = \log(0.0196 / 0.0099) \approx 0.68$

Idan bakin kofa da aka saita shine 0.5, wannan lura ($\Lambda=0.68>0.5$) zai kai ga yanke shawarar "manufa tana nan." A cikin tsarin al'ada ba tare da shela ba, wannan ƙidayar guda ɗaya ba za a iya bambanta ta da amo na baya ba. Tsarin quantum, ta hanyar la'akari da ƙidaya kawai a cikin rukunoni na lokaci masu alaƙa da shela, yana rage amo mai tasiri wanda aka yanke wannan shawara a kansa.

6. Bincike Mai Zurfi & Fassarar Kwararru

Fahimta ta Tsakiya: Wannan ba wani abin sha'awa ne kawai na dakin gwaji ba; yana da mahimmancin dabarun zuwa ga hankalin quantum mai amfani. Marubutan sun yi nasarar amfani da alaƙar quantum a kan babbar barazana a yaƙin lantarki: garkuwa. Ta hanyar mai da hankali kan tushen CW da bin diddigin baya mai sauyi, sun kai tsaye ƙirƙira don magance iyakoki (aikin bugun jini, daidaitawar tsayayye) waɗanda suka kiyaye nunin QI na baya a cikin ginshiƙin kimiyyar lissafi.

Kwararar Hankali: Hujjar takardar tana da ban sha'awa: 1) Lidar na al'ada ya gaza a ƙarƙashin amo/garkuwa. 2) Alaƙar quantum tana ba da fa'idar SNR ta asali (ka'idar). 3) Gwaje-gwajen da suka gabata sun kasance masu rauni ga yanayin amo na ainihi. 4) Ga tsarin mu wanda ke ƙarfafa fa'idar quantum tare da algorithms masu daidaitawa. 5) Yana aiki, har ma don auna nisa daidai. Kwararar tana haɗa ka'idar, injiniyanci, da aikace-aikace ba tare da katsewa ba.

Ƙarfi & Kurakurai:

Babban Ƙarfi: Ka'idar "bin diddigin baya mai sauyi" wani babban nasara ne. Ta yarda cewa muhalli (da maƙiya) ba su tsaya tsayin daka ba, suna motsawa fiye da ƙirar amo na tsayayye da aka saba da su a cikin wallafe-wallafen. Wannan wani sharadi ne ga kowane tsarin da za a iya aiwatarwa.
Babban Ƙarfi: Nuna auna nisa, ba kawai gano ba, yana da mahimmanci. Yana amsa "to me?" ta hanyar tabbatar da tsarin yana ba da bayanai masu aiki (nisa), wanda shine ainihin abin da masu amfani ke buƙata.
Yuwuwar Kuskure / Tsallakewa: Giwa a cikin daki shine hasken tushe da haɗa-haɗa na bakan wuta. Duk da yake SNR kowace haske yana da kyau, ainihin ƙimar samar da nau'i-nau'i na haske na CW SPDC yana da ƙasa. Don hankali mai nisa, wannan har yanzu wani maƙalli ne. Takardar ta yi ishara da haɗa-haɗa amma ba ta nuna shi a nan ba. Abokan hamayya da ke aiki tare da tsarin bugun jini ko guntuwar hoto na quantum (kamar bincike a MIT ko Bristol) na iya samun mafi girman ƙimar samun bayanai, ko da yake tare da ciniki daban-daban akan garkuwa.
Kuskuren Mahallin: Fa'idar 30 dB tana da ban sha'awa amma dole ne a sanya ta cikin mahallin. An auna shi da takamaiman ma'aunin al'ada (kyakkyawan hasashen jihar haɗin kai). A wasu yanayin lidar na al'ada na ainihi tare da tacewa na lokaci ko bakan wuta mai ci gaba, amfanin fa'idar tazara na iya zama mafi kunkuntar. Takardar za ta iya ƙara shiga tare da dabarun yaki da garkuwa na al'ada na zamani don kwatanta mai zurfi.

Fahimta Mai Aiki:

Ga Tsaro/Masu Ba da Kudade na R&D: Ƙara ƙarfafa ka'idoji waɗanda ke magance barazanar daidaitawa. Wannan takarda tana nuna ƙimar haɗa kayan aikin quantum tare da software mai hankali. Ya kamata kuɗi ya mayar da hankali kan tsarin haɗin kai waɗanda ke magance haske (ta hanyar haɗa-haɗa kamar yadda yake a cikin PRX Quantum 3, 020308 (2022)) da ƙarfin algorithm lokaci guda.
Ga Injiniyoyi: Gaba shine gauraye. Babban darasi shine amfani da alaƙar quantum a matsayin madaidaicin matakin tacewa maimakon kawai tushen haske. Haɗa wannan "tacewa" na quantum tare da tsarin gine-ginen lidar na al'ada da ci gaba da sarrafa sigina (misali, koyon na'ura don gane tsari a cikin bayanan daidaituwa) don mafi kyawun na'urar gani na duniya biyu.
Ga Fannin: Wannan aikin ya kafa sabon ma'auni: takardar hankali ta quantum dole ne ta nuna ƙarfi a kan yanayi masu sauyi, na adawa don a yi la'akari da aikace-aikace masu mahimmanci. Zamanin ba da rahoton fa'idar quantum kawai a cikin dakin gwaji mai shiru, da aka sarrafa ya ƙare.

7. Aikace-aikace na Gaba & Ci Gaba

Hanyar daga wannan nunin zuwa aiwatarwa tana bayyana kuma tana da bangarori da yawa:

Sa Ido na Sirri & Tsaro: Babban aikace-aikacen shine a cikin amintaccen, auna nisa da kariya daga garkuwa da hoto don dandamali masu cin gashin kansu (jukuna, jiragen ruwa) da tsaron kewaye a cikin yanayin da ake takaddama a kan lantarki.
Hoton Likita & Biophotonics: Ana iya daidaita dabaru don yin hoto ta hanyar kafofin watsawa masu yawa (misali, nama na halitta) inda amo na baya (haske mai kai da kansa) ke da babban kalubale, yana iya inganta zurfi da bambanci a cikin dabaru kamar tomography na gani mai watsawa.
Lidar na Ƙarƙashin Ruwa & Yanayi: Haɓaka quantum zai iya tsawaita kewayon aiki da daidaiton sa ido na yanayi na lidar a cikin yanayi tare da babban watsawa na barbashi, wanda ke haifar da watsawa mai amo.
Muhimman Hanyoyin Ci Gaba:
1. Haske na Tushe & Haɗawa: Canzawa daga manyan kayan gani zuwa da'irori na hoto na quantum da aka haɗa don ƙirƙirar tushen nau'i-nau'i na haske masu haske, mafi kwanciyar hankali, da ma'auni na guntu.
2. Haɗa-haɗa na Bakan Wuta & Sarari: Amfani da tashoshi masu yawa na tsawon raƙuman ruwa ko hanyoyin sarari (kamar yadda aka fara a cikin ayyuka kamar J. M. Lukens et al., Optica 7, 2020) don ƙara ƙimar bayanai da samar da ƙarin digiri na 'yanci a kan garkuwa.
3. Bincike Mai Haɓaka AI: Haɗa koyon na'ura tare da tsarin log-likelihood don rarraba manufa, ba kawai gano su ba, da kuma hasashen da hana dabarun garkuwa masu rikitarwa.
4. Aikin Tsakiyar Raƙuman Infrared (MWIR): Haɓaka tushe da na'urori masu gano don bakan MWIR ("yankin sawun yatsa") don hankali na musamman na sinadarai tare da hankali mai haɓaka quantum.

8. Nassoshi

S. Lloyd, "Haɓaka hankali na gano hoto ta hanyar hasashen quantum," Kimiyya, 2008.
S. Guha da B. I. Erkmen, "Masu karɓar hasashen quantum-jihar Gaussian don gano manufa," Phys. Rev. A, 2009.
J. H. Shapiro, "Labarin hasashen quantum," IEEE Aerospace da Mujallar Tsarin Lantarki, 2020. (Muhimmin labarin bita)
Z. Zhang et al., "Hasashen quantum na tushen haɗin kai tare da tushen nau'i-nau'i na haske da aka haɗa," PRX Quantum, 2022. (A kan haske ta hanyar haɗa-haɗa)
J. M. Lukens da R. C. Pooser, "Sarrafa siffar kowane lokaci na gani na quantum a cikin yanayin sarari guda ɗaya," Optica, 2020. (A kan haɗa-haɗa na bakan wuta)
M. G. Raymer da I. A. Walmsley, "Hanyoyin lokaci a cikin gani na quantum: sannan kuma yanzu," Physica Scripta, 2020. (Mahallin kan hanyoyin lokaci/bakan wuta)
DARPA, "Shirin Quantum Apertures (QA)". (Misalin babban kuɗin tsaro a cikin hankali na quantum)
Wannan Takarda: M. P. Mrozowski, R. J. Murchie, J. Jeffers, da J. D. Pritchard, "Nunin auna nisa mai haɓaka quantum mai tsayayya da garkuwar al'ada," [Sunan Mujalla], [Shekara].