The advantage of the quantum function evaluator is that it can take all<\/p>\n\n\n\n
possible inputs simultaneously as a superposition of states, and the corre-<\/p>\n\n\n\n
sponding outputs are all simultaneously present in the output state. This has<\/p>\n\n\n\n
often been called quantum parallelism. However, in this basic form it gives us<\/p>\n\n\n\n
no advantage, since to actually discover the value of the function, we must<\/p>\n\n\n\n
measure the output, upon which the output state will collapse to one of the<\/p>\n\n\n\n
possible outputs at random. The trick to making quantum computing work<\/p>\n\n\n\n
is to cleverly manipulate this basic function evaluator in such a way that the<\/p>\n\n\n\n
probability amplitude for the answer to the problem is maximum. It is quan-<\/p>\n\n\n\n
tum interference that enables this to happen. If this had not been possible,<\/p>\n\n\n\n
quantum computing would have been a forgotten chapter in the history of<\/p>\n\n\n\n
science. As it happens, this \ufb01eld received new impetus when Peter Shor shook<\/p>\n\n\n\n
up the world in 1994 with his famous algorithm for \ufb01nding the prime factors<\/p>\n\n\n\n
of large integers.<\/p>\n\n\n\n
All known quantum algorithms seem to fall into three broad classes:<\/p>\n\n\n\n
1. Based on the Fourier transform: Deutsch\u2013Josza, Shor\u2019s algorithm etc.<\/p>\n\n\n\n
2. Based on quantum search, involving amplitude ampli\ufb01cation: Grover\u2019s<\/p>\n\n\n\n
algorithm etc.<\/p>\n\n\n\n
3. Quantum simulations.<\/p>\n\n\n\n
In this chapter we will examine the \ufb01rst two kinds, leaving the last to more<\/p>\n\n\n\n
physics-speci\ufb01c texts. The algorithms are typically framed as yes-no answers<\/p>\n\n\n\n
to inputs to the function evaluator treated as a black box (Figure 8.2). This<\/p>\n\n\n\n
is also referred to as querying the oracle, as the unknown function evaluator<\/p>\n\n\n\n
is regarded, like a mysterious priestess who will only give single-bit answers<\/p>\n\n\n\n
when questioned!<\/p>\n\n\n\n
?<\/p>\n\n\n\n
?<\/p>\n\n\n\n
1<\/p>\n\n\n\n
FIGURE 8.2: Classical black box function evaluator as an oracle<\/p>\n","protected":false},"excerpt":{"rendered":"
The advantage of the quantum function evaluator is that it can take all possible inputs simultaneously as a superposition of states, and the corre- sponding outputs are all simultaneously present in the output state. This has often been called quantum parallelism. However, in this basic form it gives us no advantage, since to actually discover […]<\/p>\n","protected":false},"author":1,"featured_media":4042,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[497],"tags":[],"class_list":["post-4082","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-quantum-algorithms"],"jetpack_featured_media_url":"https:\/\/workhouse.sweetdishy.com\/wp-content\/uploads\/2024\/09\/algorithm-1.png","_links":{"self":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/4082","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/comments?post=4082"}],"version-history":[{"count":1,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/4082\/revisions"}],"predecessor-version":[{"id":4083,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/posts\/4082\/revisions\/4083"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/media\/4042"}],"wp:attachment":[{"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/media?parent=4082"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/categories?post=4082"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/workhouse.sweetdishy.com\/index.php\/wp-json\/wp\/v2\/tags?post=4082"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}