{"id":895923,"date":"2026-09-14T22:30:15","date_gmt":"2026-09-14T22:30:15","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/895923\/"},"modified":"2026-09-14T22:30:15","modified_gmt":"2026-09-14T22:30:15","slug":"indian-scientists-find-tool-to-control-quantum-loss-what-does-it-mean","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/895923\/","title":{"rendered":"Indian scientists find tool to control quantum loss: What does it mean?"},"content":{"rendered":"

One of the fundamental concepts in quantum physics<\/a> is entanglement, which is key to quantum computing. Entanglement, where the quantum properties of two particles can only be described together, no matter how far apart they are, however, is fleeting, and can disintegrate when entangled particles interact with the environment. This places a limit on how long quantum information can survive before what is known as \u201centanglement sudden death\u201d.<\/p>\n

\"AA quantum particle can exist in either an excited state (higher energy) or a ground state (lower energy). When two particles get entangled, their states become linked. (Pexels\/ Representational Photo)<\/p>\n

Now, scientists at the Raman Research Institute (RRI) in Bengaluru <\/a>have found a way to make quantum entanglement last longer. They use a \u201cflip operation\u201d with precise timing. This can not only delay sudden death but also prevent or hasten it.<\/p>\n

The team, in collaboration with researchers at the University of Calgary and Louisiana State University, has published its findings in the journal Physical Review A. The study was funded by the National Quantum Mission.<\/p>\n

Getting entangled<\/p>\n

A quantum particle can exist in either an excited state (higher energy) or a ground state (lower energy). When two particles get entangled, their states become linked: the combined system acts as a single, coordinated system rather than two independent objects \u2014 a property key to quantum computing. For example, either particle may be found in the excited state while the other is in the ground state.<\/p>\n

When interacting with the environment, however, the excited-state component tends to decay into the ground-state component. This weakens the entanglement, which can vanish over time.<\/p>\n

Also read: Physics Nobel: How laureates showed quantum effects on a life-size scale<\/a><\/p>\n

Timing and control<\/p>\n

The research team sought a way to delay sudden death \u2014 and found one. They used an optical setup that exploits a key property of light, whose particles, called photons, are quantum particles. The property is called polarisation, which can be vertical or horizontal depending on the orientation in which the light waves are oscillating.<\/p>\n

They took vertical polarisation to represent the excited state and horizontal polarisation the ground state, and applied a flip that swaps the two.<\/p>\n

\u201cSwapping\u201d does not mean that one photon was waiting in vertical polarisation and suddenly flipped to horizontal, said senior professor Urbasi Sinha, group leader of the Quantum Information and Computing (QuIC) lab at RRI. Her colleague Saumya Ranjan Behera is the study\u2019s lead author.<\/p>\n

\u201cWhat we control is the probability that the vertical component is converted into the horizontal one. The identification of vertical with \u2018excited\u2019 and horizontal with \u2018ground\u2019 is a choice of encoding. A photon <\/a>does not have atomic ground and excited states in this sense. What matters is that our apparatus creates a one-way quantum map: one state is stable, and the other can decay into it,\u201d Sinha told HT.<\/p>\n

The team applied the flip using a waveplate, an optical device that can change the polarisation of light. Alteration of polarisation in itself is not new. What the team achieved was control over how the entanglement subsequently decayed.<\/p>\n

It was a matter of timing: the result depended on when a single flip was introduced during the decay process.<\/p>\n

\u201cWhat is different here is that a single well-timed operation is enough to steer the entanglement dynamics. We also show theoretically that, within the class of strategies we studied, using more such operations does not help; it does worse,\u201d Sinha said.<\/p>\n

\u201cAlso,\u201d she added, \u201cthe result is not only that entanglement lasts longer. Depending on when the same operation is applied, it can do three different things: prevent sudden death, delay it, or hasten it. That is why timing is the central point.\u201d<\/p>\n

Also read: AI and quantum computers will be frenemies<\/a><\/p>\n

What it means<\/p>\n

Across quantum platforms, one of the central obstacles is decoherence, or the loss of a system\u2019s quantum properties on interaction with the environment. Sinha cautioned against interpreting the results as a solution to the problem. This is one of the big challenges in quantum computing.<\/p>\n

\u201cWe have not solved coherence. What we show is more specific: for an important kind of noise called amplitude damping, the timing of one operation can change the fate of entanglement. Our work suggests that timing could become part of the control toolbox for quantum systems,\u201d Sinha said.<\/p>\n

\u201cThere is a real removal of sudden death in that regime, but it is not immortality. We are steering the route taken by the system while it decoheres,\u201d she said.<\/p>\n

Asked about hastening sudden death, Sinha said its importance is evidential. \u201cIf one operation could only delay or protect entanglement, one might think it was simply a preservation effect. But the same operation can also make sudden death occur earlier, depending only on when it is applied,\u201d she said. That shows that timing is genuinely steering the dynamics.<\/p>\n

There is another takeaway, in terms of theoretical physics. Two standard models of quantum physics address the basic question of how quantum systems can lose information: independently, as if each particle has its own environment, or collectively, as if they share one.<\/p>\n

\u201cThe work connects the two standard ways,\u201d Sinha said.<\/p>\n","protected":false},"excerpt":{"rendered":"One of the fundamental concepts in quantum physics is entanglement, which is key to quantum computing. Entanglement, where…\n","protected":false},"author":2,"featured_media":895924,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[49,48,308665,314,105764,290,34572,5964,308666,66],"class_list":["post-895923","post","type-post","status-publish","format-standard","has-post-thumbnail","category-physics","tag-ca","tag-canada","tag-entanglement-sudden-death","tag-physics","tag-polarisation","tag-quantum-computing","tag-quantum-entanglement","tag-quantum-physics","tag-raman-research-institute","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/895923","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=895923"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/895923\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/895924"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=895923"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=895923"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=895923"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}