When you swap two paraparticles, these hidden properties change in tandem. As an analogy, imagine that these properties are colors. Start with two paraparticles, one that\u2019s internally red and another that\u2019s internally blue. When they swap places, rather than keeping these colors, they both change in corresponding ways, as prescribed by the mathematics of the particular model. Perhaps the swap leaves them green and yellow. This quickly turns into a complex game, where paraparticles affect each other in unseen ways as they move around.<\/p>\n
Meanwhile, M\u00fcller was also busy rethinking the DHR theorems. \u201cIt\u2019s not always super transparent what they mean, because it\u2019s in a very complicated mathematical framework,\u201d he said.<\/p>\n
His team took a new approach to the paraparticle question. The researchers considered the fact that quantum systems can exist in multiple possible states at once\u2014what\u2019s called a superposition. They imagined switching between the perspectives of observers who exist in these superposed states, each of whom describes their branch of reality slightly differently. If two particles are truly indistinguishable, they figured, then it won\u2019t matter if the particles are swapped in one branch of the superposition and not in the other.<\/p>\n
\u201cMaybe if the particles are close by, I swap them, but if they are far away I do nothing,\u201d M\u00fcller said. \u201cAnd if they\u2019re in a superposition of both, then I do the swapping in one branch, and nothing in the other branch.\u201d Whether observers across branches label the two particles in the same way should make no difference.<\/p>\n
This stricter definition of indistinguishability in the context of superpositions imposes new restrictions on the kinds of particles that can exist. When these assumptions hold, the researchers found that paraparticles are impossible. For a particle to be truly indistinguishable by measurement, as physicists expect elementary particles to be, it must be either a boson or fermion.<\/p>\n
Although Wang and Hazzard published their paper first, it\u2019s as though they saw M\u00fcller\u2019s constraints coming. Their paraparticles are possible because their model rejects M\u00fcller\u2019s starting assumption: The particles are not indistinguishable in the full sense required in the context of quantum superpositions. This comes with a consequence. While swapping two paraparticles has no effect on one person\u2019s measurements, two observers, by sharing their data with each other, can determine whether the paraparticles have been swapped. That\u2019s because swapping paraparticles can change how two people\u2019s measurements relate to each other. In this sense, they could tell the two paraparticles apart.<\/p>\n
This means there\u2019s a potential for new states of matter. Where bosons can pack an endless number of particles into the same state, and fermions can\u2019t share a state at all, paraparticles end up somewhere in the middle. They are able to pack just a few particles into the same state, before getting crowded and forcing others into new states. Exactly how many can be crammed together depends on the details of the paraparticle\u2014the theoretical framework allows for endless options.<\/p>\n
\u201cI find their paper really fascinating, and there\u2019s absolutely no contradiction with what we do,\u201d M\u00fcller said.<\/p>\n
The Road to Reality<\/p>\n
If paraparticles exist, they\u2019ll most likely be emergent particles, called quasiparticles, that show up as energetic vibrations in certain quantum materials.<\/p>\n
\u201cWe might get new models of exotic phases, which were difficult to understand before, that you can now solve easily using paraparticles,\u201d said Meng Cheng<\/a>, a physicist at Yale University who was not involved in the research.<\/p>\n Bryce Gadway<\/a>, an experimental physicist at Pennsylvania State University who sometimes collaborates with Hazzard, is optimistic that paraparticles will be realized in the lab in the next few years. These experiments would use Rydberg atoms, which are energized atoms with electrons that roam very far from their nuclei. This separation of the positive and negative charge makes Rydberg atoms especially sensitive to electric fields. You can build quantum computers out of interacting Rydberg atoms. They are also the perfect candidates for creating paraparticles.<\/p>\n \u201cFor a certain kind of Rydberg quantum simulator, this is kind of just what they would do naturally,\u201d Gadway said about creating paraparticles. \u201cYou just prepare them and watch them evolve.\u201d<\/p>\n But for now, the third kingdom of particles remains wholly theoretical.<\/p>\n \u201cParaparticles might become important,\u201d said Wilczek, the Nobel Prize\u2013winning physicist and inventor of anyons. \u201cBut at present they\u2019re basically a theoretical curiosity.\u201d<\/p>\n Original story<\/a> reprinted with permission from Quanta Magazine<\/a>, an editorially independent publication of the Simons Foundation<\/a> whose mission is to enhance public understanding of science by covering research developments and trends in mathematics and the physical and life sciences.<\/p>\n","protected":false},"excerpt":{"rendered":"When you swap two paraparticles, these hidden properties change in tandem. As an analogy, imagine that these properties…\n","protected":false},"author":2,"featured_media":130890,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3845],"tags":[74,10815,11112,70,16,15],"class_list":{"0":"post-130889","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-physics","9":"tag-quanta-magazine","10":"tag-quantum-physics","11":"tag-science","12":"tag-uk","13":"tag-united-kingdom"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/114569034089665072","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/130889","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=130889"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/130889\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/130890"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=130889"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=130889"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=130889"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}