Pub Date : 2025-10-22DOI: 10.1038/s41567-025-03048-8
Lorenzo Leone, Jacopo Rizzo, Jens Eisert, Sofiene Jerbi
The precise quantification of the limits to manipulating quantum resources lies at the core of quantum information theory. However, standard information-theoretic analyses do not consider the actual computational complexity involved in performing certain tasks. Here we address this issue within the realm of entanglement theory, finding that accounting for computational efficiency substantially changes what can be achieved using entangled resources. We consider two key figures of merit: the computational distillable entanglement and the computational entanglement cost. These measures quantify the optimal rates of entangled bits that can be extracted from or used to dilute many identical copies of n-qubit bipartite pure states, using computationally efficient local operations and classical communication. We demonstrate that computational entanglement measures diverge considerably from their information-theoretic counterparts. Whereas the information-theoretic distillable entanglement is determined by the von Neumann entropy of the reduced state, we show that the min-entropy governs the computationally efficient setting. On the other hand, computationally efficient entanglement dilution requires maximal consumption of entangled bits, even for nearly unentangled states. Furthermore, in the worst-case scenario, even when an efficient description of the state exists and is fully known, one gains no advantage over state-agnostic protocols. Our findings establish sample-complexity bounds for measuring and testing the von Neumann entropy, fundamental limitations on efficient state compression and efficient local tomography protocols. Previous work on the limits of quantum information processing has often assumed access to unlimited computational resources. Imposing a requirement for computational efficiency on entanglement theory substantially changes what is possible.
{"title":"Entanglement theory with limited computational resources","authors":"Lorenzo Leone, Jacopo Rizzo, Jens Eisert, Sofiene Jerbi","doi":"10.1038/s41567-025-03048-8","DOIUrl":"10.1038/s41567-025-03048-8","url":null,"abstract":"The precise quantification of the limits to manipulating quantum resources lies at the core of quantum information theory. However, standard information-theoretic analyses do not consider the actual computational complexity involved in performing certain tasks. Here we address this issue within the realm of entanglement theory, finding that accounting for computational efficiency substantially changes what can be achieved using entangled resources. We consider two key figures of merit: the computational distillable entanglement and the computational entanglement cost. These measures quantify the optimal rates of entangled bits that can be extracted from or used to dilute many identical copies of n-qubit bipartite pure states, using computationally efficient local operations and classical communication. We demonstrate that computational entanglement measures diverge considerably from their information-theoretic counterparts. Whereas the information-theoretic distillable entanglement is determined by the von Neumann entropy of the reduced state, we show that the min-entropy governs the computationally efficient setting. On the other hand, computationally efficient entanglement dilution requires maximal consumption of entangled bits, even for nearly unentangled states. Furthermore, in the worst-case scenario, even when an efficient description of the state exists and is fully known, one gains no advantage over state-agnostic protocols. Our findings establish sample-complexity bounds for measuring and testing the von Neumann entropy, fundamental limitations on efficient state compression and efficient local tomography protocols. Previous work on the limits of quantum information processing has often assumed access to unlimited computational resources. Imposing a requirement for computational efficiency on entanglement theory substantially changes what is possible.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 11","pages":"1847-1854"},"PeriodicalIF":18.4,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41567-025-03048-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145381919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-22DOI: 10.1038/s41567-025-03049-7
James O’Sullivan, Jaime Travesedo, Louis Pallegoix, Zhiyuan W. Huang, Patrick Hogan, Alexandre S. May, Boris Yavkin, Sen Lin, Ren-Bao Liu, Thierry Chaneliere, Sylvain Bertaina, Philippe Goldner, Daniel Estève, Denis Vion, Patrick Abgrall, Patrice Bertet, Emmanuel Flurin
The ability to coherently control and read out qubits is a crucial requirement for any quantum processor. Individual nuclear spins in solid-state systems have been used as long-lived qubits with control and readout performed using individual electron spin ancilla qubits that can be addressed either electrically or optically. Here we present a platform for quantum information processing, consisting of 183W nuclear spin qubits adjacent to an Er3+ impurity in a CaWO4 crystal coupled to a superconducting resonator. We study two nuclear spin qubits with $${T}_{2}^{* }$$ of 0.8(2) s and 1.2(3) s, and T2 of 3.4(4) s and 4.4(6) s, respectively. The nuclear spin state influences the number of photons emitted after repeated excitation of the Er3+ electron ancilla spin qubit, enabling quantum non-demolition readout using a single microwave photon detector. Using stimulated Raman driving on the coupled electron–nuclear-spin system, we implement all-microwave one- and two-qubit gates on a timescale of a few milliseconds, and prepare a decoherence-protected Bell state. Our results position this platform as a potential route towards quantum processing using nuclear spins. Nuclear spins in solid-state systems can have very long coherence times, which makes them attractive for use as qubits. Now a nuclear spin qubit device has been developed with all-microwave two-qubit control that has important performance benefits.
{"title":"Individual solid-state nuclear spin qubits with coherence exceeding seconds","authors":"James O’Sullivan, Jaime Travesedo, Louis Pallegoix, Zhiyuan W. Huang, Patrick Hogan, Alexandre S. May, Boris Yavkin, Sen Lin, Ren-Bao Liu, Thierry Chaneliere, Sylvain Bertaina, Philippe Goldner, Daniel Estève, Denis Vion, Patrick Abgrall, Patrice Bertet, Emmanuel Flurin","doi":"10.1038/s41567-025-03049-7","DOIUrl":"10.1038/s41567-025-03049-7","url":null,"abstract":"The ability to coherently control and read out qubits is a crucial requirement for any quantum processor. Individual nuclear spins in solid-state systems have been used as long-lived qubits with control and readout performed using individual electron spin ancilla qubits that can be addressed either electrically or optically. Here we present a platform for quantum information processing, consisting of 183W nuclear spin qubits adjacent to an Er3+ impurity in a CaWO4 crystal coupled to a superconducting resonator. We study two nuclear spin qubits with $${T}_{2}^{* }$$ of 0.8(2) s and 1.2(3) s, and T2 of 3.4(4) s and 4.4(6) s, respectively. The nuclear spin state influences the number of photons emitted after repeated excitation of the Er3+ electron ancilla spin qubit, enabling quantum non-demolition readout using a single microwave photon detector. Using stimulated Raman driving on the coupled electron–nuclear-spin system, we implement all-microwave one- and two-qubit gates on a timescale of a few milliseconds, and prepare a decoherence-protected Bell state. Our results position this platform as a potential route towards quantum processing using nuclear spins. Nuclear spins in solid-state systems can have very long coherence times, which makes them attractive for use as qubits. Now a nuclear spin qubit device has been developed with all-microwave two-qubit control that has important performance benefits.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 11","pages":"1794-1800"},"PeriodicalIF":18.4,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145382026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-22DOI: 10.1038/s41567-025-03046-w
Kun Fang
Entanglement is a powerful resource for quantum technologies but real-world computation limits can drastically change what is achievable. Now research reveals that computational constraints reshape our understanding of entanglement manipulation.
{"title":"Practical limits on entanglement manipulation","authors":"Kun Fang","doi":"10.1038/s41567-025-03046-w","DOIUrl":"10.1038/s41567-025-03046-w","url":null,"abstract":"Entanglement is a powerful resource for quantum technologies but real-world computation limits can drastically change what is achievable. Now research reveals that computational constraints reshape our understanding of entanglement manipulation.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 11","pages":"1694-1695"},"PeriodicalIF":18.4,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145381917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1038/s41567-025-03083-5
Benjamin A. Foutty, Aidan P. Reddy, Carlos R. Kometter, Kenji Watanabe, Takashi Taniguchi, Trithep Devakul, Benjamin E. Feldman
Transition metal dichalcogenide moiré homobilayers have emerged as a platform in which magnetism, strong correlations and topology are intertwined. In a large magnetic field, the energetic alignment of states with different spin in these systems is dictated by both strong Zeeman splitting and the structure of the Hofstadter’s butterfly spectrum, yet the latter has been difficult to probe experimentally. Here we observe a cascade of magnetic phase transitions in a twisted WSe2 homobilayer using local thermodynamic measurements. We interpret these transitions as the filling of individual Hofstadter subbands, enabling us to extract the structure and connectivity of the Hofstadter spectrum for a single spin. The onset of magnetic transitions is independent of twist angle, indicating that the exchange interactions of the component layers are only weakly modified by the moiré potential. By contrast, the magnetic transitions are associated with changes in the insulating states at commensurate filling. Our work achieves a spin-resolved measurement of Hofstadter’s butterfly despite overlapping states and disentangles the role of material properties and moiré superlattices in stabilizing the correlated ground states. Exploring the spin-resolved Hofstadter spectrum in the presence of interactions is challenging. Now, a series of magnetic phase transitions are observed as individual Hofstadter bands are filled, allowing the exchange interactions to be mapped out.
{"title":"Magnetic Hofstadter cascade in a twisted semiconductor homobilayer","authors":"Benjamin A. Foutty, Aidan P. Reddy, Carlos R. Kometter, Kenji Watanabe, Takashi Taniguchi, Trithep Devakul, Benjamin E. Feldman","doi":"10.1038/s41567-025-03083-5","DOIUrl":"10.1038/s41567-025-03083-5","url":null,"abstract":"Transition metal dichalcogenide moiré homobilayers have emerged as a platform in which magnetism, strong correlations and topology are intertwined. In a large magnetic field, the energetic alignment of states with different spin in these systems is dictated by both strong Zeeman splitting and the structure of the Hofstadter’s butterfly spectrum, yet the latter has been difficult to probe experimentally. Here we observe a cascade of magnetic phase transitions in a twisted WSe2 homobilayer using local thermodynamic measurements. We interpret these transitions as the filling of individual Hofstadter subbands, enabling us to extract the structure and connectivity of the Hofstadter spectrum for a single spin. The onset of magnetic transitions is independent of twist angle, indicating that the exchange interactions of the component layers are only weakly modified by the moiré potential. By contrast, the magnetic transitions are associated with changes in the insulating states at commensurate filling. Our work achieves a spin-resolved measurement of Hofstadter’s butterfly despite overlapping states and disentangles the role of material properties and moiré superlattices in stabilizing the correlated ground states. Exploring the spin-resolved Hofstadter spectrum in the presence of interactions is challenging. Now, a series of magnetic phase transitions are observed as individual Hofstadter bands are filled, allowing the exchange interactions to be mapped out.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 12","pages":"1942-1948"},"PeriodicalIF":18.4,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145381918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1038/s41567-025-03063-9
J. M. Pate, M. Goryachev, R. Y. Chiao, J. E. Sharping, M. E. Tobar
{"title":"Reply to: Inadequacy of the Casimir force for explaining a strong attractive force in a micrometre-sized narrow-gap re-entrant cavity","authors":"J. M. Pate, M. Goryachev, R. Y. Chiao, J. E. Sharping, M. E. Tobar","doi":"10.1038/s41567-025-03063-9","DOIUrl":"10.1038/s41567-025-03063-9","url":null,"abstract":"","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 11","pages":"1717-1718"},"PeriodicalIF":18.4,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145381920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1038/s41567-025-03062-w
Giuseppe Bimonte
{"title":"Inadequacy of the Casimir force for explaining a strong attractive force in a micrometre-sized narrow-gap re-entrant cavity","authors":"Giuseppe Bimonte","doi":"10.1038/s41567-025-03062-w","DOIUrl":"10.1038/s41567-025-03062-w","url":null,"abstract":"","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 11","pages":"1714-1716"},"PeriodicalIF":18.4,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145381921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-20DOI: 10.1038/s41567-025-03064-8
Gunda Kipp, Hope M. Bretscher, Benedikt Schulte, Dorothee Herrmann, Kateryna Kusyak, Matthew W. Day, Sivasruthi Kesavan, Toru Matsuyama, Xinyu Li, Sara Maria Langner, Jesse Hagelstein, Felix Sturm, Alexander M. Potts, Christian J. Eckhardt, Yunfei Huang, Kenji Watanabe, Takashi Taniguchi, Angel Rubio, Dante M. Kennes, Michael A. Sentef, Emmanuel Baudin, Guido Meier, Marios H. Michael, James W. McIver
Van der Waals heterostructures host many-body quantum phenomena that are tunable in situ using electrostatic gates. Their constituent two-dimensional materials and gates can naturally form plasmonic self-cavities, confining light in standing waves of current density due to finite-size effects. The plasmonic resonances of typical graphite gates fall in the gigahertz to terahertz range, corresponding to the same microelectronvolt to millielectronvolt energy scale as the phenomena in van der Waals heterostructures that they electrically control. This raises the possibility that the built-in cavity modes of graphite gates are relevant for shaping the low-energy physics of these heterostructures. However, probing these cavity-coupled electrodynamics is challenging as devices are notably smaller than the diffraction limit at the relevant wavelengths. Here we report on the intrinsic cavity conductivity of gate-tunable graphene heterostructures. As the carrier density is tuned, we observe coupling and spectral weight transfer between graphene and graphite plasmonic cavity modes in the ultrastrong coupling regime. We present an analytical model to describe the results and provide general principles for cavity design. Our findings show that intrinsic cavity effects are important for understanding the low-energy electrodynamics of van der Waals heterostructures and open a pathway for useful functionality through cavity control. Integrating an electronic device with a cavity can cause the electrons to couple to photons strongly enough to form hybrid modes. Now, the cavity effects induced by intrinsic graphite gates are shown to modify the low-energy properties of graphene.
{"title":"Cavity electrodynamics of van der Waals heterostructures","authors":"Gunda Kipp, Hope M. Bretscher, Benedikt Schulte, Dorothee Herrmann, Kateryna Kusyak, Matthew W. Day, Sivasruthi Kesavan, Toru Matsuyama, Xinyu Li, Sara Maria Langner, Jesse Hagelstein, Felix Sturm, Alexander M. Potts, Christian J. Eckhardt, Yunfei Huang, Kenji Watanabe, Takashi Taniguchi, Angel Rubio, Dante M. Kennes, Michael A. Sentef, Emmanuel Baudin, Guido Meier, Marios H. Michael, James W. McIver","doi":"10.1038/s41567-025-03064-8","DOIUrl":"10.1038/s41567-025-03064-8","url":null,"abstract":"Van der Waals heterostructures host many-body quantum phenomena that are tunable in situ using electrostatic gates. Their constituent two-dimensional materials and gates can naturally form plasmonic self-cavities, confining light in standing waves of current density due to finite-size effects. The plasmonic resonances of typical graphite gates fall in the gigahertz to terahertz range, corresponding to the same microelectronvolt to millielectronvolt energy scale as the phenomena in van der Waals heterostructures that they electrically control. This raises the possibility that the built-in cavity modes of graphite gates are relevant for shaping the low-energy physics of these heterostructures. However, probing these cavity-coupled electrodynamics is challenging as devices are notably smaller than the diffraction limit at the relevant wavelengths. Here we report on the intrinsic cavity conductivity of gate-tunable graphene heterostructures. As the carrier density is tuned, we observe coupling and spectral weight transfer between graphene and graphite plasmonic cavity modes in the ultrastrong coupling regime. We present an analytical model to describe the results and provide general principles for cavity design. Our findings show that intrinsic cavity effects are important for understanding the low-energy electrodynamics of van der Waals heterostructures and open a pathway for useful functionality through cavity control. Integrating an electronic device with a cavity can cause the electrons to couple to photons strongly enough to form hybrid modes. Now, the cavity effects induced by intrinsic graphite gates are shown to modify the low-energy properties of graphene.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 12","pages":"1926-1933"},"PeriodicalIF":18.4,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41567-025-03064-8.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145382368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-17DOI: 10.1038/s41567-025-03070-w
Alec Eickbusch, Matt McEwen, Volodymyr Sivak, Alexandre Bourassa, Juan Atalaya, Jahan Claes, Dvir Kafri, Craig Gidney, Christopher W. Warren, Jonathan Gross, Alex Opremcak, Nicholas Zobrist, Kevin C. Miao, Gabrielle Roberts, Kevin J. Satzinger, Andreas Bengtsson, Matthew Neeley, William P. Livingston, Alex Greene, Rajeev Acharya, Laleh Aghababaie Beni, Georg Aigeldinger, Ross Alcaraz, Trond I. Andersen, Markus Ansmann, Frank Arute, Kunal Arya, Abraham Asfaw, Ryan Babbush, Brian Ballard, Joseph C. Bardin, Alexander Bilmes, Jenna Bovaird, Dylan Bowers, Leon Brill, Michael Broughton, David A. Browne, Brett Buchea, Bob B. Buckley, Tim Burger, Brian Burkett, Nicholas Bushnell, Anthony Cabrera, Juan Campero, Hung-Shen Chang, Ben Chiaro, Liang-Ying Chih, Agnetta Y. Cleland, Josh Cogan, Roberto Collins, Paul Conner, William Courtney, Alexander L. Crook, Ben Curtin, Sayan Das, Alexander Del Toro Barba, Sean Demura, Laura De Lorenzo, Agustin Di Paolo, Paul Donohoe, Ilya K. Drozdov, Andrew Dunsworth, Aviv Moshe Elbag, Mahmoud Elzouka, Catherine Erickson, Vinicius S. Ferreira, Leslie Flores Burgos, Ebrahim Forati, Austin G. Fowler, Brooks Foxen, Suhas Ganjam, Gonzalo Garcia, Robert Gasca, Élie Genois, William Giang, Dar Gilboa, Raja Gosula, Alejandro Grajales Dau, Dietrich Graumann, Tan Ha, Steve Habegger, Michael C. Hamilton, Monica Hansen, Matthew P. Harrigan, Sean D. Harrington, Stephen Heslin, Paula Heu, Oscar Higgott, Reno Hiltermann, Jeremy Hilton, Hsin-Yuan Huang, Ashley Huff, William J. Huggins, Evan Jeffrey, Zhang Jiang, Xiaoxuan Jin, Cody Jones, Chaitali Joshi, Pavol Juhas, Andreas Kabel, Hui Kang, Amir H. Karamlou, Kostyantyn Kechedzhi, Trupti Khaire, Tanuj Khattar, Mostafa Khezri, Seon Kim, Bryce Kobrin, Alexander N. Korotkov, Fedor Kostritsa, John Mark Kreikebaum, Vladislav D. Kurilovich, David Landhuis, Tiano Lange-Dei, Brandon W. Langley, Kim-Ming Lau, Justin Ledford, Kenny Lee, Brian J. Lester, Loïck Le Guevel, Wing Yan Li, Alexander T. Lill, Aditya Locharla, Erik Lucero, Daniel Lundahl, Aaron Lunt, Sid Madhuk, Ashley Maloney, Salvatore Mandrà, Leigh S. Martin, Orion Martin, Cameron Maxfield, Jarrod R. McClean, Seneca Meeks, Anthony Megrant, Reza Molavi, Sebastian Molina, Shirin Montazeri, Ramis Movassagh, Michael Newman, Anthony Nguyen, Murray Nguyen, Chia-Hung Ni, Logan Oas, Raymond Orosco, Kristoffer Ottosson, Alex Pizzuto, Rebecca Potter, Orion Pritchard, Chris Quintana, Ganesh Ramachandran, Matthew J. Reagor, David M. Rhodes, Eliott Rosenberg, Elizabeth Rossi, Kannan Sankaragomathi, Henry F. Schurkus, Michael J. Shearn, Aaron Shorter, Noah Shutty, Vladimir Shvarts, Spencer Small, W. Clarke Smith, Sofia Springer, George Sterling, Jordan Suchard, Aaron Szasz, Alex Sztein, Douglas Thor, Eifu Tomita, Alfredo Torres, M. Mert Torunbalci, Abeer Vaishnav, Justin Vargas, Sergey Vdovichev, Guifre Vidal, Catherine Vollgraff Heidweiller, Steven Waltman, Jonathan Waltz, Shannon X. Wang, Brayden Ware, Travis Weidel, Theodore White, Kristi Wong, Bryan W. K. Woo, Maddy Woodson, Cheng Xing, Z. Jamie Yao, Ping Yeh, Bicheng Ying, Juhwan Yoo, Noureldin Yosri, Grayson Young, Adam Zalcman, Yaxing Zhang, Ningfeng Zhu, Sergio Boixo, Julian Kelly, Vadim Smelyanskiy, Hartmut Neven, Dave Bacon, Zijun Chen, Paul V. Klimov, Pedram Roushan, Charles Neill, Yu Chen, Alexis Morvan
A remarkable characteristic of quantum computing is the potential for reliable computation despite faulty qubits. This can be achieved through quantum error correction, which is typically implemented by repeatedly applying static syndrome checks, permitting correction of logical information. Recently, the development of time-dynamic approaches to error correction has enabled different codes and implementations that do not rely on static syndrome measurements. Here we experimentally demonstrate three time-dynamic implementations of the surface code, each offering a distinct solution to hardware design challenges faced by surface code realizations. First, we embed the surface code on a hexagonal lattice, reducing the necessary couplings per qubit from four to three. Second, we walk a surface code, swapping the role of data and measure qubits each round, achieving error correction with built-in removal of accumulated non-computational errors. Finally, we realize the surface code using iSWAP gates instead of the traditional CNOT, extending the set of viable gates for error correction without additional overhead. We measure the error suppression factor when scaling from distance-3 to distance-5 codes of Λ35,hex = 2.15(2), Λ35,walk = 1.69(6) and Λ35,iSWAP = 1.56(2), achieving state-of-the-art error suppression for each. Our work demonstrates that dynamic circuit approaches meet the demands for fault tolerance and enable alternative strategies for scalable hardware design. Typical quantum error correcting codes assign fixed roles to the underlying physical qubits. Now the performance benefits of alternative, dynamic error correction schemes have been demonstrated on a superconducting quantum processor.
{"title":"Demonstration of dynamic surface codes","authors":"Alec Eickbusch, Matt McEwen, Volodymyr Sivak, Alexandre Bourassa, Juan Atalaya, Jahan Claes, Dvir Kafri, Craig Gidney, Christopher W. Warren, Jonathan Gross, Alex Opremcak, Nicholas Zobrist, Kevin C. Miao, Gabrielle Roberts, Kevin J. Satzinger, Andreas Bengtsson, Matthew Neeley, William P. Livingston, Alex Greene, Rajeev Acharya, Laleh Aghababaie Beni, Georg Aigeldinger, Ross Alcaraz, Trond I. Andersen, Markus Ansmann, Frank Arute, Kunal Arya, Abraham Asfaw, Ryan Babbush, Brian Ballard, Joseph C. Bardin, Alexander Bilmes, Jenna Bovaird, Dylan Bowers, Leon Brill, Michael Broughton, David A. Browne, Brett Buchea, Bob B. Buckley, Tim Burger, Brian Burkett, Nicholas Bushnell, Anthony Cabrera, Juan Campero, Hung-Shen Chang, Ben Chiaro, Liang-Ying Chih, Agnetta Y. Cleland, Josh Cogan, Roberto Collins, Paul Conner, William Courtney, Alexander L. Crook, Ben Curtin, Sayan Das, Alexander Del Toro Barba, Sean Demura, Laura De Lorenzo, Agustin Di Paolo, Paul Donohoe, Ilya K. Drozdov, Andrew Dunsworth, Aviv Moshe Elbag, Mahmoud Elzouka, Catherine Erickson, Vinicius S. Ferreira, Leslie Flores Burgos, Ebrahim Forati, Austin G. Fowler, Brooks Foxen, Suhas Ganjam, Gonzalo Garcia, Robert Gasca, Élie Genois, William Giang, Dar Gilboa, Raja Gosula, Alejandro Grajales Dau, Dietrich Graumann, Tan Ha, Steve Habegger, Michael C. Hamilton, Monica Hansen, Matthew P. Harrigan, Sean D. Harrington, Stephen Heslin, Paula Heu, Oscar Higgott, Reno Hiltermann, Jeremy Hilton, Hsin-Yuan Huang, Ashley Huff, William J. Huggins, Evan Jeffrey, Zhang Jiang, Xiaoxuan Jin, Cody Jones, Chaitali Joshi, Pavol Juhas, Andreas Kabel, Hui Kang, Amir H. Karamlou, Kostyantyn Kechedzhi, Trupti Khaire, Tanuj Khattar, Mostafa Khezri, Seon Kim, Bryce Kobrin, Alexander N. Korotkov, Fedor Kostritsa, John Mark Kreikebaum, Vladislav D. Kurilovich, David Landhuis, Tiano Lange-Dei, Brandon W. Langley, Kim-Ming Lau, Justin Ledford, Kenny Lee, Brian J. Lester, Loïck Le Guevel, Wing Yan Li, Alexander T. Lill, Aditya Locharla, Erik Lucero, Daniel Lundahl, Aaron Lunt, Sid Madhuk, Ashley Maloney, Salvatore Mandrà, Leigh S. Martin, Orion Martin, Cameron Maxfield, Jarrod R. McClean, Seneca Meeks, Anthony Megrant, Reza Molavi, Sebastian Molina, Shirin Montazeri, Ramis Movassagh, Michael Newman, Anthony Nguyen, Murray Nguyen, Chia-Hung Ni, Logan Oas, Raymond Orosco, Kristoffer Ottosson, Alex Pizzuto, Rebecca Potter, Orion Pritchard, Chris Quintana, Ganesh Ramachandran, Matthew J. Reagor, David M. Rhodes, Eliott Rosenberg, Elizabeth Rossi, Kannan Sankaragomathi, Henry F. Schurkus, Michael J. Shearn, Aaron Shorter, Noah Shutty, Vladimir Shvarts, Spencer Small, W. Clarke Smith, Sofia Springer, George Sterling, Jordan Suchard, Aaron Szasz, Alex Sztein, Douglas Thor, Eifu Tomita, Alfredo Torres, M. Mert Torunbalci, Abeer Vaishnav, Justin Vargas, Sergey Vdovichev, Guifre Vidal, Catherine Vollgraff Heidweiller, Steven Waltman, Jonathan Waltz, Shannon X. Wang, Brayden Ware, Travis Weidel, Theodore White, Kristi Wong, Bryan W. K. Woo, Maddy Woodson, Cheng Xing, Z. Jamie Yao, Ping Yeh, Bicheng Ying, Juhwan Yoo, Noureldin Yosri, Grayson Young, Adam Zalcman, Yaxing Zhang, Ningfeng Zhu, Sergio Boixo, Julian Kelly, Vadim Smelyanskiy, Hartmut Neven, Dave Bacon, Zijun Chen, Paul V. Klimov, Pedram Roushan, Charles Neill, Yu Chen, Alexis Morvan","doi":"10.1038/s41567-025-03070-w","DOIUrl":"10.1038/s41567-025-03070-w","url":null,"abstract":"A remarkable characteristic of quantum computing is the potential for reliable computation despite faulty qubits. This can be achieved through quantum error correction, which is typically implemented by repeatedly applying static syndrome checks, permitting correction of logical information. Recently, the development of time-dynamic approaches to error correction has enabled different codes and implementations that do not rely on static syndrome measurements. Here we experimentally demonstrate three time-dynamic implementations of the surface code, each offering a distinct solution to hardware design challenges faced by surface code realizations. First, we embed the surface code on a hexagonal lattice, reducing the necessary couplings per qubit from four to three. Second, we walk a surface code, swapping the role of data and measure qubits each round, achieving error correction with built-in removal of accumulated non-computational errors. Finally, we realize the surface code using iSWAP gates instead of the traditional CNOT, extending the set of viable gates for error correction without additional overhead. We measure the error suppression factor when scaling from distance-3 to distance-5 codes of Λ35,hex = 2.15(2), Λ35,walk = 1.69(6) and Λ35,iSWAP = 1.56(2), achieving state-of-the-art error suppression for each. Our work demonstrates that dynamic circuit approaches meet the demands for fault tolerance and enable alternative strategies for scalable hardware design. Typical quantum error correcting codes assign fixed roles to the underlying physical qubits. Now the performance benefits of alternative, dynamic error correction schemes have been demonstrated on a superconducting quantum processor.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 12","pages":"1994-2001"},"PeriodicalIF":18.4,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41567-025-03070-w.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145381922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-16DOI: 10.1038/s41567-025-03033-1
Germaine Arend, Guanhao Huang, Armin Feist, Yujia Yang, Jan-Wilke Henke, Zheru Qiu, Hao Jeng, Arslan Sajid Raja, Rudolf Haindl, Rui Ning Wang, Tobias J. Kippenberg, Claus Ropers
Free electrons are a universal source of electromagnetic fields, and fundamentally their quantized energy exchange may facilitate generating tunable quantum light. Because the quantum features of the emitted radiation are encoded in the joint electronic and photonic state, they can only be revealed by a measurement accessing both subsystems. Here we demonstrate the coherent parametric generation of such non-classical states of light by free electrons. Investigating electron–photon correlations, we show that the quantized electron energy loss heralds the number of photons generated in a dielectric waveguide. In Hanbury Brown–Twiss measurements, we observe an electron-heralded single-photon state using antibunching intensity correlation, whereas two-quantum energy losses of individual electrons yield pronounced two-photon coincidences. Our results will enable the tailored preparation of higher-number Fock and other optical quantum states on the basis of controlled interactions with free-electron beams. When free electrons emit light, an entangled electron–photon state is created. Here measurements of the correlated multiparticle system have been used to produce non-classical photonic states.
{"title":"Electrons herald non-classical light","authors":"Germaine Arend, Guanhao Huang, Armin Feist, Yujia Yang, Jan-Wilke Henke, Zheru Qiu, Hao Jeng, Arslan Sajid Raja, Rudolf Haindl, Rui Ning Wang, Tobias J. Kippenberg, Claus Ropers","doi":"10.1038/s41567-025-03033-1","DOIUrl":"10.1038/s41567-025-03033-1","url":null,"abstract":"Free electrons are a universal source of electromagnetic fields, and fundamentally their quantized energy exchange may facilitate generating tunable quantum light. Because the quantum features of the emitted radiation are encoded in the joint electronic and photonic state, they can only be revealed by a measurement accessing both subsystems. Here we demonstrate the coherent parametric generation of such non-classical states of light by free electrons. Investigating electron–photon correlations, we show that the quantized electron energy loss heralds the number of photons generated in a dielectric waveguide. In Hanbury Brown–Twiss measurements, we observe an electron-heralded single-photon state using antibunching intensity correlation, whereas two-quantum energy losses of individual electrons yield pronounced two-photon coincidences. Our results will enable the tailored preparation of higher-number Fock and other optical quantum states on the basis of controlled interactions with free-electron beams. When free electrons emit light, an entangled electron–photon state is created. Here measurements of the correlated multiparticle system have been used to produce non-classical photonic states.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 11","pages":"1855-1862"},"PeriodicalIF":18.4,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41567-025-03033-1.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145381771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-15DOI: 10.1038/s41567-025-03068-4
C. Paillard, B. Dkhil
Controlling polar skyrmions — topological textures of electric dipoles — is crucial for modern optoelectronic applications. Terahertz excitation is shown to govern ultrafast manipulation of polar skyrmions featuring signature vibrational modes.
{"title":"Vibrational responses of polar skyrmions","authors":"C. Paillard, B. Dkhil","doi":"10.1038/s41567-025-03068-4","DOIUrl":"10.1038/s41567-025-03068-4","url":null,"abstract":"Controlling polar skyrmions — topological textures of electric dipoles — is crucial for modern optoelectronic applications. Terahertz excitation is shown to govern ultrafast manipulation of polar skyrmions featuring signature vibrational modes.","PeriodicalId":19100,"journal":{"name":"Nature Physics","volume":"21 12","pages":"1877-1878"},"PeriodicalIF":18.4,"publicationDate":"2025-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145381770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：