L’ordinateur quantique : qu’est-ce que c’est ?

Les ordinateurs quantiques apparaissent comme la nouvelle frontière de l’informatique. Via l’exploitation des caractéristiques des particules subatomiques, ils promettent un bond en avant en termes de performances et de rapidité. Ils rendront possibles des modélisations (celle de l’univers par exemple) ou des chiffrements très avancées. L’informatique quantique s’appuie sur des qubits, des unités de stockage d’un nouveau genre. Alors qu’en informatique « classique », un bit peut prendre les valeurs « 0 » ou « 1 », en informatique quantiquele qubit peut avoir une valeur de « 0 », « 1 » ou bien les deux en même temps (selon le principe de superposition). Ce qui décuple les capacités de calcul en parallèle.

Les notions de base d’un ordinateur quantique

La notion d’ordinateur quantique est née dans les années 1970 et 1980. Elle est notamment portée par le physicien américain David Wineland – qui a d’ailleurs reçu le Prix Nobel de physique pour ses recherches dans ce domaine. Derrière ce concept figure l’idée selon laquelle les phénomènes quantiques pourraient être utilisés pour décupler la puissance de calcul des machines classiques. Alors que les ordinateurs d’aujourd’hui utilisent le bit comme unité fondamentale, le calculateur quantique, lui, s’adosse sur une valeur appelée le qubit (ou quantum bit). Une valeur qui permettrait non seulement de s’exprimer par le biais de 1 et 0, mais également par une superposition des deux.

Mais comment alors créer un qubit d’information ? Très schématiquement, le fonctionnement d’un qubit (que l’on peut comparer à un atome artificiel) repose sur différents phénomènes de physique nucléaire. C’est aussi la raison pour laquelle l’ordinateur est dit quantique. Il fait en effet référence à la physique quantique décrivant le comportement des atomes et particules. Quels sont ces phénomènes nucléaires ? Un qubit peut être créé en s’appuyant par exemple sur la polarisation d’un photon (et la mesure du plan de polarisation), ou bien sur le niveau d’énergie d’un atome, ou les moments cinétiques de « spin », ou révolution, de l’électron autour de lui.

Comment passer du bit au qubit ?

Il existe plusieurs techniques pour créer des qubits. Grâce aux supraconducteurs, ils peuvent être embarqués sur des circuit électroniques dotés de semi-conducteurs fabriqués à partir de méthodes déjà connues, empruntées à la nanoélectronique.

Un obstacle de taille : le système doit rester totalement isolé le temps du calcul

Reste un obstacle technique de taille avant de faire fonctionner un ordinateur quantique. Le système, pendant la phase de calcul, doit être totalement isolé de toute interférence thermique ou magnétique. Du fait de la physique nucléaire qui le met en musique, le qubit est en effet sensible à toute perturbation, notamment les champs électromagnétiques. Les chercheurs appellent le temps de « décohérence » la période pendant laquelle le système reste ainsi isolé, l’intégrité de ses propriétés quantiques étant alors complètes.



  1. We’d like to offer you the job phenibut reddit anxiety « There was a period a few years ago where it seemed like thebest thing for a movie in the Oscar race was to lose at theGolden Globes, » said Fandango’s chief correspondent and awardsexpert, Dave Karger.

  2. I’d like to tell you about a change of address pure cambogia ultra philippines The pope also blasted gossiping among officials as a form of « satanic assassination. » He said: « Sometimes, officials of the Curia feel themselves ‘lords of the manor’ – superior to everyone and everything. »

  3. Very funny pictures valium and xanax high « The decision on the Saudi agreement had been made some timeago, » the newspaper Dagens Nyheter quoted Prime Minister StefanLofven as saying in the Ukrainian capital Kiev

  4. One moment, please order sildenafil Why did Hezbollah avoid a damaging and comprehensive response, which would have forced Israel to remove its kid gloves and cause a lethal chain reaction? The answer is, probably, in Tehran’s hands

  5. One moment, please oral bactrim for mrsa « Small villages and large cities surrounded by the Ukrainianarmy which is directly hitting residential areas with the aim ofdestroying the infrastructure, » he said

  6. The line’s engaged ketoconazole 200 mg tablets The staffer got on the Carnival Magic ship before two of the hospital’s nurses were diagnosed with the deadly disease and before the Centers for Disease Control and Prevention issued stringent, active monitoring requirements for the staff.

  7. I’m happy very good site bios life complete cholesterol If given access, inspectors would be able to perform tests that can confirm whether or not the site had ever been used for nuclear activity since it is nearly impossible to remove traces of certain nuclear materials where they have once been used or stored.

  8. What university do you go to? bactrim or amoxicillin for uti
    Many Democrats believe Netanyahu, who Republicans hope will attack Obama’s efforts to cut a nuclear deal with Iran, aims to use the high-profile March 3 speech to boost his chances in his own March 17 election.

  9. Where are you from? testify august alsina lyrics deutsch How many of you have made health-related New Year resolutions? From quitting smoking to losing weight, it’s probably fair to say that a large chunk of the population is planning to at least try to be healthier during 2015.

  10. How many are there in a book? valium in sri lanka Eileen Carey, 29, also credits Lean In directly with inspiring her to found her company, Glassbreakers, a peer-mentoring platform for women

  11. How many more years do you have to go? modafinil sympathomimetic Supporters of GMO labeling say foods made with GMOingredients can be harmful to human health due to pesticideresidues and the altered crop genetics, and consumers deserve toknow if the food they eat are made with gene-altered corn,soybeans, sugar beets and other biotech crops.

  12. Whereabouts in are you from? ibuprofen dose child per kg As well as rejecting calls for a gradual shift in taxation to rebalance fuel duty and vehicle excise duty, Mr Hawes dismissed diesel scrappage scheme policies, commenting: “We want to make sure that any measures to improve air quality are focused on urban areas, so a scrappage scheme might be a bit of a blunt instrument.”

  13. How much does the job pay? lipocils expert отзыв Imports from Mongolia stood at 2.22 million tonnes for thefirst two months of 2015, a gain of 70 percent over the sameperiod last year, while those from Australia dropped 25.4percent to 3.8 million tonnes.

  14. Will I be paid weekly or monthly? lifecell india charges « This was an obvious proof that what now rules the Russiancurrency is not oil, or even waiting for its move, but panicfuelled by a large number of rumours about the return of ourcountry to the « 98-year » regime, » said Alena Afanasyeva, asenior analyst at Forex Club in Moscow.

  15. It’s a pity you don’t have a donate button! I’d certainly donate
    to this superb blog! I guess for now i’ll settle for bookmarking and adding your RSS feed to my Google account.
    I look forward to new updates and will talk about this site with my Facebook group.
    Talk soon!

  16. Have you read any good books lately? zymax badminton string review
    « The key driver is that by doing this, they’re better able to compete with the tobacco companies, » said Mark Winkler of Fleming Family & Partners, who advised British e-cigarette maker Skycig on its sale to Lorillard in October for 30 million pounds ($49.58 million) plus future payments.

  17. I’d like , please zofran in pregnancy class In the end their use in supporting infantry in seizing territory was deemed too important but, since the 2010 Strategic Defence and Security Review, Britain’s tank arsenal has fallen to 334 tanks across three brigades, including just 168 Challenger 2s.

  18. What part of do you come from? boiling point online simulation « An interesting point made was that as burnout reduced their mental/physical health and work competence, it also reduced their ability to recognise that they were suffering from burnout

  19. I’m training to be an engineer prednisone brand for sale uk The editorial stances highlighted differences over how publishers respond to the shootings and raised questions overwhether many were already self-censoring for fear of causingoffence or, worse still, triggering an Islamist backlash.

  20. Canada>Canada provenge sales 2013 Berry’s alma mater, Tennessee, wore helmet stickers honoring him in a recent game, and the Chiefs designed a shirt that reads, « Be Bold Be Brave Be Berry. » Arizona coach Bruce Arians wore one of the shirts before the Cardinals’ game against the Chiefs, and they are being sold online and at Arrowhead Stadium with proceeds going to the Leukemia and Lymphoma Society.

  21. Very interesting tale enalapril maleate 10 mg price RiverBay is calling for a state investigation of its charges against Marion Scott, but the corporation may not be able to cut ties with the management company under terms of its financing deal with the government and Wells Fargo Bank.

  22. What do you do for a living? plasmanate dosing
    Nino Zambakhidze, chairman of the Georgian Farmers Association, a group of 900 farmers from across the country, says some members are concerned about the costs of getting the internationally-recognised quality certification which is required before they can start exporting to the EU.

  23. I like it a lot discount pharmacy in canada The following month the country carried out its second underground nuclear test and announced that it no longer considered itself bound by the terms of the 1953 truce that ended the war between the two Koreas.

  24. I’ll put her on can you take valium and hydroxyzine together They have learned by rote a set of instructions – Things To Say To The Family – that are indeed the right things to say: Your relative is gravely ill; we want to do everything we can to make him comfortable; we want you to participate in his « pain management ».

  25. Excellent blog here! Also your site loads up very fast!
    What web host are you using? Can I get your affiliate link to your host?
    I wish my site loaded up as quickly as yours

  26. Recorded Delivery zofran 4mg odt cost Vet visits, vaccinations and monthly meds”it’s all part of being a responsible pet owner — it’s up to you to do the right thing for your furry mate And the more preventative work you can do, the less likely your vet bill will escalate out of control.

  27. Do you know what extension he’s on? ms contin er 30 mg Liam Tung is an Australian business technology journalist living a few too many Swedish miles north of Stockholm for his liking

  28. What sort of music do you like? glipizide xl classification Under a “High Ebola” scenario, in which the virus spreads beyond the current locations to neighbouring Nigeria and Ivory Coast, the World Bank estimated the cost to these economies would be $32.6bn (20.3bn) – or 3.3pc of the combined GDPs of the countries affected – by the end of next year.

  29. I’ve come to collect a parcel generic xanax not working Northern Ireland subsequently saw decades of violent conflict between those campaigning for a united Ireland, and those wishing to stay in the United Kingdom.

  30. A book of First Class stamps equivalent du viagra en homeopathie The map, which was compiled by researchers at NUI Maynooth, revealed that people living in poorer areas of Dublin were significantly more likely to die of cancer compared to those living in more affluent areas.

  31. I need to charge up my phone order myo pure clayton Nearly seven months after the Protection of Life During Pregnancy Act came into effect, health professionals have to date only been issued with guidelines on how the appeals system where a woman is refused an abortion should operate.

  32. Hello good day zyvox linezolid Mubarak, 86, was sentenced to life in prison in 2012 for conspiring to murder 239 demonstrators, sowing chaos and creating a security vacuum during the 18-day revolt, but an appeals court ordered a retrial.

  33. Nice to meet you migranex 5 mg tab « I was very glad that this Thanksgiving was the year that you two were supposed to go to your in-laws’, and I’m hoping you’ll have some of this out of your system when you come here for Christmas.

  34. Remove card power growth and alpha fuel 720 side effects Some content providers that are considering joining videostreaming services are mulling caps that would trigger newnegotiations if viewership reaches certain levels, said twomedia executives who asked not to be named because of thesensitivity of the issue.

  35. i’m fine good work alkem ketorolac 10mg One of the largest, known as Lohafex, was an Indian-German experiment in 2009 which involved dumping six tonnes of an iron solution into the South Atlantic to encourage plankton to bloom – trapping carbon which would then be sent to the seabed when the organisms died

  36. Is there ? lancome hypnose waterproof mascara black « A stronger Ukrainian military, with enhanced defensivecapabilities, will increase the prospects for negotiation of apeaceful settlement, » said a report by the Washington-basedAtlantic Council, which suggested military aid should includelight anti-armour missiles, drones and armoured Humvees.

  37. magic story very thanks eat better america white chicken chili The Cancer Treatment Centers of America (CTCA), a private, for-profit operator of cancer treatment hospitals and outpatient clinics, will treat NFL Alumni who are fighting prostate cancer, which afflicts almost one in seven U.S

  38. How much does the job pay? lisinopril 20 mg description newborns during the first week of life has decreased by 8 percent in recent years, but the rate of stillbirths late in pregnancy has held steady, according to a new report from the Centers for Disease Control and Prevention (CDC).

  39. I’ve come to collect a parcel nildep 75 Since campaigning began in mid-November, both the ruling and opposition camps have reported violent attacks which have killed a number of their supporters.

  40. Oh my goodness! Impressive article dude!
    Thanks, However I am experiencing problems with your RSS.

    I don’t understand why I am unable to join it. Is there anybody
    else having similar RSS issues? Anybody who knows the answer can you kindly respond?

  41. I simply want to tell you that I am just new to blogs and absolutely enjoyed this web page. More than likely I’m want to bookmark your site . You actually have exceptional articles. Thanks for revealing your website page.

  42. Hi! I simply want to offer you a huge thumbs up for
    your great information you’ve got right here on this
    post. I am coming back to your site for more soon.

  43. After going over a number of the blog articles on your site, I truly like your way of blogging.

    I added it to my bookmark site list and will be checking back in the near future.
    Please visit my website too and let me know your opinion.

  44. I visited multiplemanyseveralvarious websitessitesweb sitesweb pagesblogs butexcepthowever the audio qualityfeature for audio songs currentpresentexisting at this websiteweb sitesiteweb page is reallyactuallyin facttrulygenuinely marvelouswonderfulexcellentfabuloussuperb.

  45. Sorry for the huge review, but I’m really loving the new Zune, and hope this, as well as the excellent reviews some other people have written, will help you decide if it’s the right choice for you.

  46. Terrific paintings! This is the kind of information that should be shared around the web. Shame on Google for not positioning this submit upper! Come on over and seek advice from my website . Thanks =)

  47. Heya i am for the first time here. I found this board and I find It truly useful & it helped me out a lot. I hope to give something back and help others like you helped me.

  48. I simply could not depart your web site before suggesting that I really enjoyed the standard info an individual supply in your visitors? Is gonna be back often in order to check out new posts

  49. Thank you so much for providing individuals with an exceptionally nice chance to read from this website. It really is so superb and as well , full of a great time for me personally and my office acquaintances to visit your website the equivalent of three times weekly to see the newest tips you have got. And lastly, we’re at all times amazed concerning the attractive things you give. Some two points in this article are without a doubt the very best I’ve ever had.

  50. I want to express thanks to you for bailing me out of this particular matter. Just after surfing around through the internet and finding thoughts which are not powerful, I believed my entire life was gone. Existing minus the solutions to the problems you’ve fixed all through your main guide is a serious case, and the kind that could have badly affected my entire career if I had not come across your blog post. Your good understanding and kindness in controlling all the pieces was excellent. I’m not sure what I would have done if I had not come across such a point like this. I am able to now look ahead to my future. Thanks for your time very much for this impressive and effective guide. I won’t be reluctant to refer your site to any person who desires guidance about this subject.

  51. Hi, Neat post. There’s a problem along with your site in web explorer, may check this¡K IE nonetheless is the market chief and a huge component of folks will pass over your great writing due to this problem.

  52. Thank you for sharing excellent informations. Your site is so cool. I’m impressed by the details that you’ve on this website. It reveals how nicely you perceive this subject. Bookmarked this web page, will come back for extra articles. You, my friend, ROCK! I found just the information I already searched all over the place and just couldn’t come across. What a great web site.

  53. I’m extremely impressed with your writing skills and also with the layout on your weblog. Is this a paid theme or did you customize it yourself? Anyway keep up the nice quality writing, it’s rare to see a great blog like this one today..

  54. I truly appreciate this post. I’ve been looking everywhere for this! Thank goodness I found it on Bing. You have made my day! Thanks again!

  55. I will right away take hold of your rss as I can’t to find your e-mail subscription link or newsletter service. Do you have any? Please permit me recognise so that I may just subscribe. Thanks.

  56. Greetings from Florida! I’m bored to death at work so
    I decided to check out your site on my iphone
    during lunch break. I really like the info you provide
    here and can’t wait to take a look when I get home.
    I’m surprised at how fast your blog loaded on my cell phone ..
    I’m not even using WIFI, just 3G .. Anyways, excellent site!

  57. Someone essentially assist to make seriously articles I’d state. That is the first time I frequented your website page and up to now? I amazed with the analysis you made to create this particular post extraordinary. Excellent process!

  58. Hello There. I found your blog using msn. This is a really well written article. I’ll be sure to bookmark it and return to read more of your useful information. Thanks for the post. I’ll definitely return.

  59. Magnificent beat ! I would like to apprentice while you amend your web site, how can i subscribe for a blog website? The account helped me a acceptable deal. I had been tiny bit acquainted of this your broadcast offered bright clear idea

  60. greatwonderfulfantasticmagnificentexcellent postsubmitpublishput up, very informative. I wonderI’m wonderingI ponder why the otherthe opposite expertsspecialists of this sector do notdon’t realizeunderstandnotice this. You shouldmust continueproceed your writing. I amI’m sureconfident, you haveyou’ve a hugea great readers’ base already!

  61. Hello There. I found your blog using msn. This is a very well written article. I’ll be sure to bookmark it and come back to read more of your useful information. Thanks for the post. I will certainly return.

  62. Somebody necessarily assist to make severely posts I might state. This is the first time I frequented your web page and up to now? I surprised with the analysis you made to make this actual post amazing. Great job!

  63. Good – I should definitely pronounce, impressed with your site. I had no trouble navigating through all the tabs as well as related info ended up being truly easy to do to access. I recently found what I hoped for before you know it in the least. Quite unusual. Is likely to appreciate it for those who add forums or anything, website theme . a tones way for your client to communicate. Nice task.

  64. whoah this weblog is excellent i like studying your articles. Keep up the great paintings! You understand, lots of persons are hunting around for this information, you can aid them greatly.

  65. Thank you for sharing superb informations. Your web-site is very cool. I’m impressed by the details that you’ve on this blog. It reveals how nicely you perceive this subject. Bookmarked this website page, will come back for extra articles. You, my friend, ROCK! I found simply the information I already searched all over the place and just couldn’t come across. What a great web-site.

  66. HiHello, i thinki feeli believe that i sawnoticed you visited my blogweblogwebsiteweb sitesite sothus i got herecame to go backreturn the preferchoosefavorwantdesire?.I amI’m trying toattempting to in findingfindto find thingsissues to improveenhance my websitesiteweb site!I guessI assumeI suppose its good enoughokadequate to useto make use of some ofa few of your ideasconceptsideas!!

  67. I truly appreciate this post. I’ve been looking everywhere for this! Thank goodness I found it on Bing. You have made my day! Thank you again!

  68. What i do not realize is in reality how you’re now not really much more neatly-favored than you may be now. You’re very intelligent. You know thus considerably relating to this matter, made me in my view consider it from so many numerous angles. Its like men and women aren’t interested until it is something to accomplish with Woman gaga! Your personal stuffs nice. Always deal with it up!

  69. Magnificent goods from you, man. I’ve understand your stuff previous to and you are just extremely wonderful. I actually like what you have acquired here, certainly like what you’re saying and the way in which you say it. You make it enjoyable and you still take care of to keep it sensible. I can not wait to read far more from you. This is really a terrific website.

  70. Wow! This can be one particular of the most beneficial blogs We’ve ever arrive across on this subject. Actually Fantastic. I am also a specialist in this topic so I can understand your effort.

  71. Fantastic beat ! I wish to apprentice while you amend your website, how can i subscribe for a blog site? The account aided me a acceptable deal. I had been tiny bit acquainted of this your broadcast provided bright clear concept

  72. I and my pals have been following the good guides found on your website and then got a terrible suspicion I never thanked the web blog owner for them. Most of the people had been for that reason glad to see them and now have sincerely been taking advantage of those things. We appreciate you getting really kind and for going for these kinds of quality issues millions of individuals are really needing to know about. Our sincere regret for not expressing gratitude to sooner.

  73. I truly wanted to type a simple remark so as to appreciate you for all of the magnificent points you are giving at this site. My extended internet look up has at the end of the day been rewarded with reputable content to exchange with my company. I would assume that most of us readers actually are very much lucky to exist in a very good website with very many perfect people with useful principles. I feel very much privileged to have discovered your site and look forward to tons of more fun minutes reading here. Thanks once again for all the details.

  74. I¡¦ve recently started a web site, the info you offer on this site has helped me tremendously. Thank you for all of your time & work.

  75. Hi there, You’ve done a fantastic job. I’ll definitely digg it and personally recommend to my friends. I am confident they will be benefited from this website.

  76. Wow! This can be one particular of the most helpful blogs We’ve ever arrive across on this subject. Actually Wonderful. I’m also a specialist in this topic so I can understand your hard work.

  77. I’m not sure where you’re getting your information, but good topic. I needs to spend some time learning more or understanding more. Thanks for fantastic information I was looking for this info for my mission.

  78. I have been browsing online more than three hours today, yet I never found any interesting article like yours. It is pretty worth enough for me. In my opinion, if all web owners and bloggers made good content as you did, the net will be much more useful than ever before.

  79. I genuinely enjoy looking at on this internet site, it has got good articles. « The living is a species of the dead and not a very attractive one. » by Friedrich Wilhelm Nietzsche.

  80. hi!,I really like your writing so much! percentage we keep up a correspondence more approximately your post on AOL? I need an expert in this area to solve my problem. Maybe that’s you! Looking ahead to look you.

  81. This design is wickedspectacularstellerincredible! You certainlyobviouslymost certainlydefinitely know how to keep a reader entertainedamused. Between your wit and your videos, I was almost moved to start my own blog (well, almost…HaHa!) GreatWonderfulFantasticExcellent job. I really enjoyedloved what you had to say, and more than that, how you presented it. Too cool!

Laisser un commentaire

Votre adresse de messagerie ne sera pas publiée.