{"id":132781,"date":"2026-05-21T14:00:33","date_gmt":"2026-05-21T18:00:33","guid":{"rendered":"https:\/\/www.simonsfoundation.org\/?p=132781"},"modified":"2026-05-12T12:25:27","modified_gmt":"2026-05-12T16:25:27","slug":"quantum-dynamics-breakthrough-overturns-claim-of-quantum-supremacy-opens-new-research-directions","status":"publish","type":"post","link":"https:\/\/www.simonsfoundation.org\/2026\/05\/21\/quantum-dynamics-breakthrough-overturns-claim-of-quantum-supremacy-opens-new-research-directions\/","title":{"rendered":"Quantum Dynamics Breakthrough Overturns Claim of \u2018Quantum Supremacy,\u2019 Opens New Research Directions"},"content":{"rendered":"","protected":false},"excerpt":{"rendered":"","protected":false},"author":432,"featured_media":132783,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_relevanssi_hide_post":"","_relevanssi_hide_content":"","_relevanssi_pin_for_all":"","_relevanssi_pin_keywords":"","_relevanssi_unpin_keywords":"","_relevanssi_related_keywords":"","_relevanssi_related_include_ids":"","_relevanssi_related_exclude_ids":"","_relevanssi_related_no_append":"","_relevanssi_related_not_related":"","_relevanssi_related_posts":"","_relevanssi_noindex_reason":"","footnotes":""},"categories":[369],"tags":[],"class_list":["post-132781","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-ccq","news_type-press-release"],"acf":{"block_editor":[{"acf_fc_layout":"image","type":"image_large","image":132782,"title":"Tensor networks enable researchers to tackle quantum physics problems previously thought to be solvable only by quantum computers. ","caption":"Lucy Reading-Ikkanda\/Simons Foundation","caption_full":"","less_margin":false},{"acf_fc_layout":"text","text":"Using a conventional computer and cutting-edge mathematical tools and code, physicists at the Center for Computational Quantum Physics (CCQ) at the Simons Foundation's Flatiron Institute<\/a> and collaborators at Boston University have cracked a daunting quantum physics problem previously claimed to be solvable only by quantum computers.\r\n\r\nThe technique is so groundbreaking in its efficiency that the researchers were even able to use a personal laptop to solve the problem. By enabling scientists to squeeze extra problem-solving power from classical computers, the breakthrough methodology is opening new avenues for research on quantum dynamics and may be useful as a protocol for solving problems about finding the optimal solution amid an abundance of feasible ones.\r\n\r\nThe researchers report their work May 21 in Science<\/em><\/a>.\r\n\r\nThe problem at hand involves simulating a quantum system composed of hundreds of interacting \u2018qubits\u2019 \u2014 the quantum computing equivalent of the bits used in classical computers \u2014 arranged in square, cubic or diamond lattices. While bits can have values of 0 or 1, qubits can exist in a superposition of multiple values, making it challenging for traditional computers to simulate their dynamics.\r\n\r\nIn a March 2025 article, also published in Science<\/em><\/a>, a group of quantum computing researchers reported that they\u2019d calculated the dynamics of a particularly intricate system of qubits using a quantum computer. They further claimed that their feat was impossible for classical computers to match.\r\n\r\n\u201cWhenever we [at the CCQ] see these kinds of claims, we\u2019re always a bit skeptical,\u201d says Joseph Tindall<\/a>, an associate research scientist at the CCQ and first author on the new Science<\/em> paper. \u201cLike, \u2018Did you try this? Did you try that?\u2019\u201d\r\n\r\nThe problem served as an opportunity to take their tools \u201cout for a test drive,\u201d says study co-author and CCQ research scientist Miles Stoudenmire<\/a>. \u201cWe could have picked some more arbitrary target,\u201d Stoudenmire says. \u201cBut it was like \u2018Why not pick this one that has a big claim attached to it?\u2019\u201d\r\n\r\nThe work was particularly challenging due to quantum entanglement, which means the qubits can\u2019t be treated individually, even when they're far apart. That entanglement requires sophisticated algorithms to tackle, Tindall says.\r\n\r\n\u201cWhen you have lots of particles that interact by quantum physics, you have this wave function that describes the state of the system,\u201d Tindall says. \u201cIt\u2019s this huge object that rapidly gets bigger and bigger the more particles there are.\u201d\r\n\r\nAs the wave function\u2019s size grows exponentially, \u201cI just can\u2019t directly store it on my computer,\u201d he says. Working with such massive wave functions is a common challenge in quantum physics, but it\u2019s required for tasks such as predicting the properties of quantum materials, like superconductors."},{"acf_fc_layout":"image","type":"image_medium","image":132785,"title":"","caption":"Lucy Reading-Ikkanda\/Simons Foundation","caption_full":"","less_margin":false},{"acf_fc_layout":"text","text":"The CCQ team achieved their breakthrough by developing and implementing new tools based on tensor networks, which Tindall likens to \u201ca zip file for the wave function where you\u2019ve taken all this information, and you\u2019ve compressed it into this mathematical data structure full of these small tables of numbers that are interconnected to each other.\u201d\r\n\r\nThe tensor networks made the problem feasible for classical computers. Tindall performed many of the initial calculations on a laptop computer using code from a high-performance tensor network software library developed at the CCQ called ITensor<\/a>. The recently published simulations exemplify how the ITensor team is discovering new ways to repurpose tensor methods for novel applications. Those simulations capture the three-dimensional dynamics using a 3D tensor network.\r\n\r\n\u201cIt\u2019s this very powerful compression that can be very effective, but it\u2019s a pretty complex mathematical object,\u201d Tindall says. \u201cThis really is a bit of a frontier, because working with these objects \u2014 especially in three dimensions \u2014 is very untrodden. You need sophisticated codes and algorithms to deal with them; it\u2019s a software engineering challenge in itself.\u201d\r\n\r\nThe team ran many of their simulations using relatively modest computational resources. Tindall performed the initial calculations using an older type of algorithm \u2014 called belief propagation \u2014 from the 1980s that has been recently adapted for quantum systems. \u201cIt\u2019s a little more approximate than some of the other methods, but it\u2019s way cheaper, and we can run it much more directly on lots of harder problems,\u201d Stoudenmire says. He contrasts that with \u201cmore sophisticated methods in the past of our field\u201d that \u201cwouldn\u2019t be able to even start going for some of these three-dimensional problems, because they\u2019re so big.\u201d\r\n\r\nDespite using only modest computational hardware, the researchers demonstrated that their simulations yielded state-of-the-art accuracies. The simulations converged on solutions that matched theoretical predictions and provided accurate results when applied to smaller test problems. The results also agreed with those reported by the quantum computing researchers \u2014 but with no quantum computer required.\r\n\r\nWhile researchers in classical and quantum computing may seem to be at odds with each other about the limitations of their respective subfields, Tindall and Stoudenmire note that there\u2019s also shared knowledge and inspiration to be found between the two approaches.\r\n\r\n\u201cThe good side of the classical versus quantum computing debate is that there\u2019s a lot of synergy between the kind of simulations we\u2019re interested in and the codes we write and what can be realized on these quantum computers,\u201d Tindall says. \u201cThat can help guide us, and it can also help guide quantum computing researchers, because, obviously, the barrier for entry for us to simulate certain things is a lot easier than for them, because we don\u2019t have to build a quantum computer. I can just write some code and press \u2018run\u2019 on my personal computer.\u201d\r\n\r\nThe team is pushing their work even further by developing tools for going beyond qubit systems to problems involving electrons that can move between sites \u2014 an even more daunting challenge that connects directly to simulating quantum materials. \u201cThey\u2019re really, quantitatively, a lot harder problems,\u201d Stoudenmire says. \u201cSo that\u2019s one of our next big bars that we want to clear.\u201d"},{"acf_fc_layout":"divider"},{"acf_fc_layout":"subtitle","title":"Information for Press","is_chapter":false,"is_inline":false,"margin_bottom":""},{"acf_fc_layout":"text","text":"For more information, please contact press@simonsfoundation.org<\/a>.\r\n