{"id":1065,"date":"2005-09-15T19:12:16","date_gmt":"2005-09-16T02:12:16","guid":{"rendered":"http:\/\/dabacon.org\/pontiff\/?p=1065"},"modified":"2005-09-15T19:12:16","modified_gmt":"2005-09-16T02:12:16","slug":"quantum-dot-qubits","status":"publish","type":"post","link":"https:\/\/dabacon.org\/pontiff\/2005\/09\/15\/quantum-dot-qubits\/","title":{"rendered":"Quantum Dot Qubits"},"content":{"rendered":"<p>I had seen these results in a previous talk, but now the <a href=\"http:\/\/www.sciencemag.org\/lookup\/resid\/1116955v1?view=abstract&amp;uritype=cgi&amp;view=abstract\">paper<\/a> is out in <del datetime=\"2005-09-16T11:31:26-08:00\">Nature<\/del> Science.  Charles Marcus&#8217;s group at Harvard has been working on building a qubit from a semiconductor quantum dot.  One of the difficulties for this type of qubit is that the qubit couples via a hyperfine interaction to surrounding nuclei.  If you don&#8217;t do anything about this hyperfine interaction, this causes a typical Rabi flopping experiment to exhibit decoherence rates of 10 nanoseconds.  Way to short to make a useful quantum computer!  But what is nice about the hyperfine decoherence mechanism, is that it is a constant coupling which can be overcome by doing a spin echo experiment.  In the above paper, Marcus and colleagues show that with appropriate spin echo techniques, they get lifetimes of 1 microseconds.  Nothing like that many orders of magnitude improvement, no?<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I had seen these results in a previous talk, but now the paper is out in Nature Science. Charles Marcus&#8217;s group at Harvard has been working on building a qubit from a semiconductor quantum dot. One of the difficulties for this type of qubit is that the qubit couples via a hyperfine interaction to surrounding &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/dabacon.org\/pontiff\/2005\/09\/15\/quantum-dot-qubits\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;Quantum Dot Qubits&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":false,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[20,53,63],"tags":[],"class_list":["post-1065","post","type-post","status-publish","format-standard","hentry","category-computer-science","category-physics","category-quantum"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/posts\/1065","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/comments?post=1065"}],"version-history":[{"count":0,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/posts\/1065\/revisions"}],"wp:attachment":[{"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/media?parent=1065"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/categories?post=1065"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/dabacon.org\/pontiff\/wp-json\/wp\/v2\/tags?post=1065"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}