{"id":67269,"date":"2025-10-08T10:58:14","date_gmt":"2025-10-08T05:28:14","guid":{"rendered":"https:\/\/vajiramandravi.com\/current-affairs\/?p=67269"},"modified":"2025-10-08T11:47:51","modified_gmt":"2025-10-08T06:17:51","slug":"nobel-physics-2025-how-quantum-circuits-became-real","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/current-affairs\/nobel-physics-2025-how-quantum-circuits-became-real\/","title":{"rendered":"Nobel Physics 2025: How Quantum Circuits Became Real"},"content":{"rendered":"<h2><b>Nobel Physics 2025 Latest News<\/b><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The <\/span><b>2025 Nobel Prize in Physics<\/b><span style=\"font-weight: 400;\"> went to <\/span><b>John Clarke, Michel Devoret, and John Martinis<\/b><span style=\"font-weight: 400;\"> for demonstrating that <\/span><b>quantum tunnelling<\/b><span style=\"font-weight: 400;\"> \u2014 <\/span><i><span style=\"font-weight: 400;\">where particles cross barriers they shouldn\u2019t be able to<\/span><\/i><span style=\"font-weight: 400;\"> \u2014 can occur not only in subatomic particles but also in macroscopic superconducting circuits.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Their pioneering work proved that quantum phenomena, once thought to exist only at the atomic and subatomic scale, can also occur in man-made electrical circuits visible to the naked eye.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">It paved the way for technologies that could transform computing, sensing, and communication.<\/span><\/li>\n<\/ul>\n<h2><b>Quantum Tunnelling and Energy Quantisation Made Visible<\/b><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The Nobel laureates \u2014 John Clarke, Michel Devoret, and John Martinis \u2014 demonstrated two of quantum physics\u2019 defining principles, <\/span><b>tunnelling<\/b><span style=\"font-weight: 400;\"> and <\/span><b>energy quantisation<\/b><span style=\"font-weight: 400;\">, in a <\/span><b>macroscopic electric circuit<\/b><span style=\"font-weight: 400;\">.<\/span><\/li>\n<\/ul>\n<h3><b>The Josephson Junction: Heart of the Discovery<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">At the core of their experiments lies the <\/span><b>Josephson junction<\/b><span style=\"font-weight: 400;\">, <\/span><span style=\"font-weight: 400;\">a device where two superconductors are separated by a thin insulating barrier<\/span><span style=\"font-weight: 400;\">.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The researchers asked whether the phase difference \u2014 a measurable electrical property \u2014 across this junction could behave like a single quantum particle.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">By sending current through the circuit, they observed that when it was small, electrons (in Cooper pairs) were trapped, producing no voltage.\u00a0<\/span>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Cooper pairs are\u00a0pairs of electrons bound together by an attractive force, mediated by lattice vibrations called <\/span><b>phonons<\/b><span style=\"font-weight: 400;\">, that occurs at low temperatures in superconducting materials.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">These pairs, which have opposite spins and total zero spin, behave as a single quantum unit called a <\/span><b>boson<\/b><span style=\"font-weight: 400;\"> and can flow through the material without resistance, enabling superconductivity.\u00a0<\/span><\/li>\n<\/ul>\n<\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">But sometimes, the current \u201ctunnelled\u201d through the barrier, suddenly flowing freely and generating a measurable voltage.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">This <\/span><b>confirmed macroscopic quantum tunnelling<\/b><span style=\"font-weight: 400;\"> \u2014 a quantum leap happening in an entire electrical circuit.<\/span><\/li>\n<\/ul>\n<h3><b>Solving the Fragility Problem<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Early efforts to detect quantum tunnelling failed because of environmental noise and microwave interference.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The Berkeley team, led by Clarke, solved this by using special filters, shielding, and ultra-cold, stable setups to isolate the circuit.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">When cooled to <\/span><b>near absolute zero<\/b><span style=\"font-weight: 400;\">, the system behaved exactly as quantum theory predicted \u2014 <\/span><span style=\"font-weight: 400;\">the rate of tunnelling became independent of temperature<\/span><span style=\"font-weight: 400;\">, confirming it wasn\u2019t due to thermal noise but a true quantum process.<\/span><\/li>\n<\/ul>\n<h3><b>Revealing Quantum Energy Levels<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The team then looked for quantised energy states, a hallmark of quantum behaviour.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">By shining microwaves of varying frequencies on the junction, they saw that when the <\/span><b>frequency matched the energy gap between two levels<\/b><span style=\"font-weight: 400;\">, the circuit \u201cescaped\u201d more easily from its trapped state.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">This showed that the <\/span><b>circuit absorbed and emitted discrete packets of energy, behaving like a macroscopic atom<\/b><span style=\"font-weight: 400;\">.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">For the first time, scientists saw quantum behaviour in a system visible to the naked eye.<\/span><\/li>\n<\/ul>\n<h3><b>Blueprint for Quantum Control<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">These experiments proved two key ideas:<\/span>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><b>Macroscopic electrical circuits<\/b><span style=\"font-weight: 400;\"> can exhibit <\/span><b>quantum properties<\/b><span style=\"font-weight: 400;\"> when isolated from noise.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><span style=\"font-weight: 400;\">Their behaviour can be <\/span><b>described using standard quantum mechanics<\/b><span style=\"font-weight: 400;\">.<\/span><\/li>\n<\/ul>\n<\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The work also established methods for controlling and reading macroscopic quantum states using bias currents and microwaves \u2014 techniques that became the foundation for superconducting qubits and quantum measurement systems.<\/span><\/li>\n<\/ul>\n<h2><b>Bridging the Quantum and the Everyday World<\/b><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">For years, scientists questioned <\/span><b>how large a system could be and still exhibit quantum effects<\/b><span style=\"font-weight: 400;\">. Normally, quantum behaviour disappears when many particles interact.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">But the Nobel laureates \u2014 John Clarke, Michel Devoret, and John Martinis \u2014 proved that with superconducting materials, extreme cooling, and precision engineering, even a visible electronic chip can display clear quantum phenomena.<\/span><\/li>\n<\/ul>\n<h2><b>Applications: From Quantum Chips to Sensors<\/b><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The laureates\u2019 findings underpin many modern quantum technologies:<\/span>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><b>Superconducting qubits<\/b><span style=\"font-weight: 400;\">: Circuits that act like artificial atoms and are the basis of quantum computers by Google, IBM, and others.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><b>Quantum sensors<\/b><span style=\"font-weight: 400;\">: Devices capable of detecting tiny magnetic fields or gravitational variations, useful in medical diagnostics and geophysical exploration.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><b>Quantum amplifiers<\/b><span style=\"font-weight: 400;\">: Boost faint signals without adding noise, vital for space exploration and dark matter detection.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><b>Metrology<\/b><span style=\"font-weight: 400;\">: Josephson junctions now define electrical standards like the volt and ampere with quantum-level precision.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"2\"><b>Microwave-to-optical converters<\/b><span style=\"font-weight: 400;\">: Link quantum processors to optical fibre networks for quantum communication.<\/span><\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h3><b>Turning Fragility into Functionality<\/b><\/h3>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">Ultimately, these devices are powerful because even <\/span><b>minute external changes<\/b><span style=\"font-weight: 400;\"> cause <\/span><b>large, measurable shifts<\/b><span style=\"font-weight: 400;\"> in the circuit\u2019s quantum state.\u00a0<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The laureates\u2019 work transformed this <\/span><b>sensitivity \u2014 once a limitation \u2014 into a defining feature<\/b><span style=\"font-weight: 400;\">, creating tools that bridge <\/span><b>quantum theory and real-world technology<\/b><span style=\"font-weight: 400;\">.<\/span><\/li>\n<\/ul>\n<p><b>Source:<\/b><strong> <a href=\"https:\/\/indianexpress.com\/article\/technology\/science\/nobel-prize-physics-2025-when-quantum-got-big-to-hold-10293177\/\" target=\"_blank\" rel=\"nofollow noopener\">IE<\/a> | <a href=\"https:\/\/www.thehindu.com\/sci-tech\/science\/why-did-macroscopic-quantum-tunnelling-win-the-2025-physics-nobel\/article70135609.ece\" target=\"_blank\" rel=\"nofollow noopener\">TH<\/a> | <a href=\"https:\/\/indianexpress.com\/article\/explained\/explained-sci-tech\/physics-nobel-2025-winners-quantum-physics-10293558\/\" target=\"_blank\" rel=\"nofollow noopener\">IE<\/a><\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Nobel Physics 2025 honours Clarke, Devoret, and Martinis for proving that quantum tunnelling and energy quantisation can occur in superconducting circuits, powering future quantum tech.<\/p>\n","protected":false},"author":18,"featured_media":67355,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[18],"tags":[60,3123,22,59],"class_list":{"0":"post-67269","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-upsc-mains-current-affairs","8":"tag-mains-articles","9":"tag-nobel-physics-2025","10":"tag-upsc-current-affairs","11":"tag-upsc-mains-current-affairs","12":"no-featured-image-padding"},"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/67269","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/users\/18"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/comments?post=67269"}],"version-history":[{"count":0,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/posts\/67269\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media\/67355"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/media?parent=67269"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/categories?post=67269"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/current-affairs\/wp-json\/wp\/v2\/tags?post=67269"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}