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Harley D, Datta I, Klausen FR, Bluhm A, França DS, Werner AH, Christandl M. Going beyond gadgets: the importance of scalability for analogue quantum simulators. Nat Commun 2024; 15:6527. [PMID: 39095397 PMCID: PMC11297168 DOI: 10.1038/s41467-024-50744-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Accepted: 07/19/2024] [Indexed: 08/04/2024] Open
Abstract
Quantum hardware has the potential to efficiently solve computationally difficult problems in physics and chemistry to reap enormous practical rewards. Analogue quantum simulation accomplishes this by using the dynamics of a controlled many-body system to mimic those of another system; such a method is feasible on near-term devices. We show that previous theoretical approaches to analogue quantum simulation suffer from fundamental barriers which prohibit scalable experimental implementation. By introducing a new mathematical framework and going beyond the usual toolbox of Hamiltonian complexity theory with an additional resource of engineered dissipation, we show that these barriers can be overcome. This provides a powerful new perspective for the rigorous study of analogue quantum simulators.
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Affiliation(s)
- Dylan Harley
- Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark.
| | - Ishaun Datta
- Stanford University, 450 Serra Mall, Stanford, CA, 94305, USA
| | - Frederik Ravn Klausen
- Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Andreas Bluhm
- Univ. Grenoble Alpes, CNRS, Grenoble INP, LIG, 38000, Grenoble, France
| | | | - Albert H Werner
- Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
| | - Matthias Christandl
- Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, 2100, Copenhagen, Denmark
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2
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Menon SG, Glachman N, Pompili M, Dibos A, Bernien H. An integrated atom array-nanophotonic chip platform with background-free imaging. Nat Commun 2024; 15:6156. [PMID: 39039068 PMCID: PMC11263554 DOI: 10.1038/s41467-024-50355-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 07/09/2024] [Indexed: 07/24/2024] Open
Abstract
Arrays of neutral atoms trapped in optical tweezers have emerged as a leading platform for quantum information processing and quantum simulation due to their scalability, reconfigurable connectivity, and high-fidelity operations. Individual atoms are promising candidates for quantum networking due to their capability to emit indistinguishable photons that are entangled with their internal atomic states. Integrating atom arrays with photonic interfaces would enable distributed architectures in which nodes hosting many processing qubits could be efficiently linked together via the distribution of remote entanglement. However, many atom array techniques cease to work in close proximity to photonic interfaces, with atom detection via standard fluorescence imaging presenting a major challenge due to scattering from nearby photonic devices. Here, we demonstrate an architecture that combines atom arrays with up to 64 optical tweezers and a millimeter-scale photonic chip hosting more than 100 nanophotonic cavities. We achieve high-fidelity ( ~ 99.2%), background-free imaging in close proximity to nanofabricated cavities using a multichromatic excitation and detection scheme. The atoms can be imaged while trapped a few hundred nanometers above the dielectric surface, which we verify using Stark shift measurements of the modified trapping potential. Finally, we rearrange atoms into defect-free arrays and load them simultaneously onto the same or multiple devices.
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Affiliation(s)
- Shankar G Menon
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Noah Glachman
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Matteo Pompili
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA
| | - Alan Dibos
- Argonne National Laboratory, Center for Nanoscale Materials, Lemont, IL, 60439, USA
- Nanoscience and Technology Division, Argonne National Laboratory, Lemont, IL, 60439, USA
- Argonne National Laboratory, Center for Molecular Engineering, Lemont, IL, 60439, USA
| | - Hannes Bernien
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA.
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3
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Petiziol F. Non-Abelian Anyons in Periodically Driven Abelian Spin Liquids. PHYSICAL REVIEW LETTERS 2024; 133:036601. [PMID: 39094173 DOI: 10.1103/physrevlett.133.036601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Revised: 04/26/2024] [Accepted: 05/30/2024] [Indexed: 08/04/2024]
Abstract
We show that non-Abelian anyons can emerge from an Abelian topologically ordered system subject to local time-periodic driving. This is illustrated with the toric-code model, as the canonical representative of a broad class of Abelian topological spin liquids. The Abelian anyons in the toric code include fermionic and bosonic quasiparticle excitations which see each other as π fluxes; namely, they result in the accumulation of a π phase if wound around each other. Non-Abelian behavior emerges because the Floquet modulation can engineer a nontrivial band topology for the fermions, inducing their fractionalization into Floquet-Majorana modes bound to the bosons. The latter then develop non-Abelian character akin to vortices in topological superconductors, realizing Ising topological order. Our findings shed light on the nonequilibrium physics of driven topologically ordered quantum matter and may facilitate the observation of non-Abelian behavior in engineered quantum systems.
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4
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Hangleiter D, Gullans MJ. Bell Sampling from Quantum Circuits. PHYSICAL REVIEW LETTERS 2024; 133:020601. [PMID: 39073933 DOI: 10.1103/physrevlett.133.020601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 05/31/2024] [Indexed: 07/31/2024]
Abstract
A central challenge in the verification of quantum computers is benchmarking their performance as a whole and demonstrating their computational capabilities. In this Letter, we find a universal model of quantum computation, Bell sampling, that can be used for both of those tasks and thus provides an ideal stepping stone toward fault tolerance. In Bell sampling, we measure two copies of a state prepared by a quantum circuit in the transversal Bell basis. We show that the Bell samples are classically intractable to produce and at the same time constitute what we call a "circuit shadow": from the Bell samples we can efficiently extract information about the quantum circuit preparing the state, as well as diagnose circuit errors. In addition to known properties that can be efficiently extracted from Bell samples, we give several new and efficient protocols: an estimator of state fidelity, an error-mitigated estimator of Pauli expectation values, a test for the depth of a circuit, and an algorithm to estimate a lower bound on the number of T gates in the circuit. With some additional measurements, the latter algorithm can be used to learn a full description of states prepared by circuits with low T count.
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5
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Hartung L, Seubert M, Welte S, Distante E, Rempe G. A quantum-network register assembled with optical tweezers in an optical cavity. Science 2024; 385:179-183. [PMID: 38991069 DOI: 10.1126/science.ado6471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 05/31/2024] [Indexed: 07/13/2024]
Abstract
Quantum computation and quantum communication are expected to provide users with capabilities inaccessible by classical physics. However, scalability to larger systems with many qubits is challenging. One solution is to develop a quantum network consisting of small-scale quantum registers containing computation qubits that are reversibly interfaced to communication qubits. In this study, we report on a register that uses both optical tweezers and optical lattices to deterministically assemble a two-dimensional array of atoms in an optical cavity. Harnessing a single atom-addressing beam, we stimulate the emission of a photon from each atom and demonstrate multiplexed atom-photon entanglement with a generation-to-detection efficiency approaching 90%. Combined with cavity-mediated quantum logic, our approach provides a possible route to distributed quantum information processing.
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Affiliation(s)
- Lukas Hartung
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
| | | | - Stephan Welte
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Institute for Quantum Electronics, ETH Zürich, 8093 Zürich, Switzerland
| | | | - Gerhard Rempe
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
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6
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Tao R, Ammenwerth M, Gyger F, Bloch I, Zeiher J. High-Fidelity Detection of Large-Scale Atom Arrays in an Optical Lattice. PHYSICAL REVIEW LETTERS 2024; 133:013401. [PMID: 39042791 DOI: 10.1103/physrevlett.133.013401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 01/16/2024] [Accepted: 04/24/2024] [Indexed: 07/25/2024]
Abstract
Recent advances in quantum simulation based on neutral atoms have largely benefited from high-resolution, single-atom sensitive imaging techniques. A variety of approaches have been developed to achieve such local detection of atoms in optical lattices or optical tweezers. For alkaline-earth and alkaline-earth-like atoms, the presence of narrow optical transitions opens up the possibility of performing novel types of Sisyphus cooling, where the cooling mechanism originates from the capability to spatially resolve the differential optical level shifts in the trap potential. Up to now, it has been an open question whether high-fidelity imaging could be achieved in a "repulsive Sisyphus" configuration, where the trap depth of the ground state exceeds that of the excited state involved in cooling. Here, we demonstrate high-fidelity (99.971(1)%) and high-survival (99.80(5)%) imaging of strontium atoms using repulsive Sisyphus cooling. We use an optical lattice as a pinning potential for atoms in a large-scale tweezer array with up to 399 tweezers and show repeated, high-fidelity lattice-tweezer-lattice transfers. We furthermore demonstrate loading the lattice with approximately 10 000 atoms directly from the MOT and scalable imaging over >10 000 lattice sites with a combined survival probability and classification fidelity better than 99.2%. Our lattice thus serves as a locally addressable and sortable reservoir for continuous refilling of optical tweezer arrays in the future.
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7
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Khazali M. Universal terminal for cloud quantum computing. Sci Rep 2024; 14:15412. [PMID: 38965311 PMCID: PMC11224409 DOI: 10.1038/s41598-024-65899-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2023] [Accepted: 06/25/2024] [Indexed: 07/06/2024] Open
Abstract
To bring the quantum computing capacities to the personal edge devices, the optimum approach is to have simple non-error-corrected personal devices that offload the computational tasks to scalable quantum computers via edge servers with cryogenic components and fault-tolerant schemes. Hence the network elements deploy different encoding protocols. This article proposes quantum terminals that are compatible with different encoding protocols; paving the way for realizing mobile edge-quantum computing. By accommodating the atomic lattice processor inside a cavity, the entangling mechanism is provided by the Rydberg cavity-QED technology. The auxiliary atom, responsible for photon emission, senses the logical qubit state via the long-range Rydberg interaction. In other words, the state of logical qubit determines the interaction-induced level-shift at the central atom and hence derives the system over distinguished eigenstates, featuring photon emission at the early or late times controlled by quantum interference. Applying an entanglement-swapping gate on two emitted photons would make the far-separated logical qubits entangled regardless of their encoding protocols. The proposed scheme provides a universal photonic interface for clustering the processors and connecting them with the quantum memories and quantum cloud compatible with different encoding formats.
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8
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Fung F, Rosenfeld E, Schaefer JD, Kabcenell A, Gieseler J, Zhou TX, Madhavan T, Aslam N, Yacoby A, Lukin MD. Toward Programmable Quantum Processors Based on Spin Qubits with Mechanically Mediated Interactions and Transport. PHYSICAL REVIEW LETTERS 2024; 132:263602. [PMID: 38996281 DOI: 10.1103/physrevlett.132.263602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Revised: 05/03/2024] [Accepted: 05/09/2024] [Indexed: 07/14/2024]
Abstract
Solid-state spin qubits are promising candidates for quantum information processing, but controlled interactions and entanglement in large, multiqubit systems are currently difficult to achieve. We describe a method for programmable control of multiqubit spin systems, in which individual nitrogen-vacancy (NV) centers in diamond nanopillars are coupled to magnetically functionalized silicon nitride mechanical resonators in a scanning probe configuration. Qubits can be entangled via interactions with nanomechanical resonators while programmable connectivity is realized via mechanical transport of qubits in nanopillars. To demonstrate the feasibility of this approach, we characterize both the mechanical properties and the magnetic field gradients around the micromagnet placed on the nanobeam resonator. We demonstrate coherent manipulation of a spin qubit in the proximity of a transported micromagnet by utilizing nuclear spin memory and use the NV center to detect the time-varying magnetic field from the oscillating micromagnet, extracting a spin-mechanical coupling of 7.7(9) Hz. With realistic improvements, the high-cooperativity regime can be reached, offering a new avenue toward scalable quantum information processing with spin qubits.
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Affiliation(s)
| | | | | | | | | | - T X Zhou
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | | | - N Aslam
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Institute of Condensed Matter Physics, Technische Universität Braunschweig, Braunschweig, Germany
- Felix Bloch Institute for Solid State Physics, Leipzig University, 04103 Leipzig, Germany
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9
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Yi K, Hai YJ, Luo K, Chu J, Zhang L, Zhou Y, Song Y, Liu S, Yan T, Deng XH, Chen Y, Yu D. Robust Quantum Gates against Correlated Noise in Integrated Quantum Chips. PHYSICAL REVIEW LETTERS 2024; 132:250604. [PMID: 38996251 DOI: 10.1103/physrevlett.132.250604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 05/22/2024] [Indexed: 07/14/2024]
Abstract
As quantum circuits become more integrated and complex, additional error sources that were previously insignificant start to emerge. Consequently, the fidelity of quantum gates benchmarked under pristine conditions falls short of predicting their performance in realistic circuits. To overcome this problem, we must improve their robustness against pertinent error models besides isolated fidelity. Here, we report the experimental realization of robust quantum gates in superconducting quantum circuits based on a geometric framework for diagnosing and correcting various gate errors. Using quantum process tomography and randomized benchmarking, we demonstrate robust single-qubit gates against quasistatic noise and spatially correlated noise in a broad range of strengths, which are common sources of coherent errors in large-scale quantum circuits. We also apply our method to nonstatic noises and to realize robust two-qubit gates. Our Letter provides a versatile toolbox for achieving noise-resilient complex quantum circuits.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Yuanzhen Chen
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Dapeng Yu
- Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- International Quantum Academy (SIQA), Shenzhen 518048, China
- Guangdong Provincial Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China
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10
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Klüsener V, Pucher S, Yankelev D, Trautmann J, Spriestersbach F, Filin D, Porsev SG, Safronova MS, Bloch I, Blatt S. Long-Lived Coherence on a μHz Scale Optical Magnetic Quadrupole Transition. PHYSICAL REVIEW LETTERS 2024; 132:253201. [PMID: 38996237 DOI: 10.1103/physrevlett.132.253201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Accepted: 04/29/2024] [Indexed: 07/14/2024]
Abstract
We report on the coherent excitation of the ultranarrow ^{1}S_{0}-^{3}P_{2} magnetic quadrupole transition in ^{88}Sr. By confining atoms in a state insensitive optical lattice, we achieve excitation fractions of 97(1)% and observe linewidths as narrow as 58(1) Hz. With Ramsey spectroscopy, we find coherence times of 14(1) ms, which can be extended to 266(36) ms using a spin-echo sequence. We determine the lifetime of the ^{3}P_{2} level for spontaneous emission of magnetic quadrupole radiation to be 110(31) min, confirming long-standing theoretical predictions. These results establish an additional clock transition in strontium and pave the way for applications of the metastable ^{3}P_{2} state in quantum computing and quantum simulations.
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11
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Haug T, Lee S, Kim MS. Efficient Quantum Algorithms for Stabilizer Entropies. PHYSICAL REVIEW LETTERS 2024; 132:240602. [PMID: 38949346 DOI: 10.1103/physrevlett.132.240602] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 05/08/2024] [Accepted: 05/10/2024] [Indexed: 07/02/2024]
Abstract
Stabilizer entropies (SEs) are measures of nonstabilizerness or "magic" that quantify the degree to which a state is described by stabilizers. SEs are especially interesting due to their connections to scrambling, localization and property testing. However, applications have been limited so far as previously known measurement protocols for SEs scale exponentially with the number of qubits. Here, we efficiently measure SEs for integer Rényi index n>1 via Bell measurements. The SE of N-qubit quantum states can be measured with O(n) copies and O(nN) classical computational time, where for even n we additionally require the complex conjugate of the state. We provide efficient bounds of various nonstabilizerness monotones that are intractable to compute beyond a few qubits. Using the IonQ quantum computer, we measure SEs of random Clifford circuits doped with non-Clifford gates and give bounds for the stabilizer fidelity, stabilizer extent, and robustness of magic. We provide efficient algorithms to measure Clifford-averaged 4n-point out-of-time-order correlators and multifractal flatness. With these measures we study the scrambling time of doped Clifford circuits and random Hamiltonian evolution depending on nonstabilizerness. Counterintuitively, random Hamiltonian evolution becomes less scrambled at long times, which we reveal with the multifractal flatness. Our results open up the exploration of nonstabilizerness with quantum computers.
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12
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Homeier L, Harris TJ, Blatz T, Geier S, Hollerith S, Schollwöck U, Grusdt F, Bohrdt A. Antiferromagnetic Bosonic t-J Models and Their Quantum Simulation in Tweezer Arrays. PHYSICAL REVIEW LETTERS 2024; 132:230401. [PMID: 38905661 DOI: 10.1103/physrevlett.132.230401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 08/03/2023] [Accepted: 05/09/2024] [Indexed: 06/23/2024]
Abstract
The combination of optical tweezer arrays with strong interactions-via dipole exchange of molecules and Van der Waals interactions of Rydberg atoms-has opened the door for the exploration of a wide variety of quantum spin models. A next significant step will be the combination of such settings with mobile dopants. This will enable one to simulate the physics believed to underlie many strongly correlated quantum materials. Here, we propose an experimental scheme to realize bosonic t-J models via encoding the local Hilbert space in a set of three internal atomic or molecular states. By engineering antiferromagnetic (AFM) couplings between spins, competition between charge motion and magnetic order similar to that in high-T_{c} cuprates can be realized. Since the ground states of the 2D bosonic AFM t-J model we propose to realize have not been studied extensively before, we start by analyzing the case of two dopants-the simplest instance in which their bosonic statistics plays a role-and compare our results to the fermionic case. We perform large-scale density matrix renormalization group calculations on six-legged cylinders, and find a strong tendency for bosonic holes to form stripes. This demonstrates that bosonic, AFM t-J models may contain similar physics as the collective phases in strongly correlated electrons.
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Affiliation(s)
- Lukas Homeier
- Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität München, Theresienstr. 37, München D-80333, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, München D-80799, Germany
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | | | | | | | | | | | | | - Annabelle Bohrdt
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, München D-80799, Germany
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- Institute of Theoretical Physics, University of Regensburg, Regensburg D-93053, Germany
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13
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Xu W, Lv C, Zhou Q. Multipolar condensates and multipolar Josephson effects. Nat Commun 2024; 15:4786. [PMID: 38839836 PMCID: PMC11153559 DOI: 10.1038/s41467-024-48907-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 05/16/2024] [Indexed: 06/07/2024] Open
Abstract
When single-particle dynamics are suppressed in certain strongly correlated systems, dipoles arise as elementary carriers of quantum kinetics. These dipoles can further condense, providing physicists with a rich realm to study fracton phases of matter. Whereas recent theoretical discoveries have shown that an unconventional lattice model may host a dipole condensate as the ground state, we show that dipole condensates prevail in bosonic systems due to a self-proximity effect. Our findings allow experimentalists to manipulate the phase of a dipole condensate and deliver dipolar Josephson effects, where supercurrents of dipoles arise in the absence of particle flows. The self-proximity effects can also be utilized to produce a generic multipolar condensate. The kinetics of the n-th order multipoles unavoidably creates a condensate of the (n + 1)-th order multipoles, forming a hierarchy of multipolar condensates that will offer physicists a whole new class of macroscopic quantum phenomena.
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Affiliation(s)
- Wenhui Xu
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - Chenwei Lv
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA
| | - Qi Zhou
- Department of Physics and Astronomy, Purdue University, West Lafayette, IN, 47907, USA.
- Purdue Quantum Science and Engineering Institute, Purdue University, West Lafayette, IN, 47907, USA.
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14
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Huang R, Zhou F, Li X, Xu P, Wang Y, Zhan M. Metasurface optical trap array for single atoms. OPTICS EXPRESS 2024; 32:21293-21303. [PMID: 38859487 DOI: 10.1364/oe.525454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2024] [Accepted: 05/13/2024] [Indexed: 06/12/2024]
Abstract
Metasurfaces made of subwavelength silicon nanopillars provide unparalleled capacity to manipulate light, and have emerged as one of the leading platforms for developing integrated photonic devices. In this study, we report on a compact, passive approach based on planar metasurface optics to generate large optical trap arrays. The unique configuration is achieved with a meta-hologram to convert a single incident laser beam into an array of individual beams, followed up with a metalens to form multiple laser foci for single rubidium atom trapping. We experimentally demonstrate two-dimensional arrays of 5 × 5 and 25 × 25 at the wavelength of 830 nm, validating the capability and scalability of our metasurface design. Beam waists ∼1.5 µm, spacings (about 15 µm), and low trap depth variations (8%) of relevance to quantum control for an atomic array are achieved in a robust and efficient fashion. The presented work highlights a compact, stable, and scalable trap array platform well-suitable for Rydberg-state mediated quantum gate operations, which will further facilitate advances in neutral atom quantum computing.
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15
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Ye J, Zoller P. Essay: Quantum Sensing with Atomic, Molecular, and Optical Platforms for Fundamental Physics. PHYSICAL REVIEW LETTERS 2024; 132:190001. [PMID: 38804927 DOI: 10.1103/physrevlett.132.190001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Indexed: 05/29/2024]
Abstract
Atomic, molecular, and optical (AMO) physics has been at the forefront of the development of quantum science while laying the foundation for modern technology. With the growing capabilities of quantum control of many atoms for engineered many-body states and quantum entanglement, a key question emerges: what critical impact will the second quantum revolution with ubiquitous applications of entanglement bring to bear on fundamental physics? In this Essay, we argue that a compelling long-term vision for fundamental physics and novel applications is to harness the rapid development of quantum information science to define and advance the frontiers of measurement physics, with strong potential for fundamental discoveries. As quantum technologies, such as fault-tolerant quantum computing and entangled quantum sensor networks, become much more advanced than today's realization, we wonder what doors of basic science can these tools unlock. We anticipate that some of the most intriguing and challenging problems, such as quantum aspects of gravity, fundamental symmetries, or new physics beyond the minimal standard model, will be tackled at the emerging quantum measurement frontier. Part of a series of Essays which concisely present author visions for the future of their field.
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Affiliation(s)
- Jun Ye
- JILA, National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - Peter Zoller
- Institute for Theoretical Physics, University of Innsbruck, 6020 Innsbruck, Austria and Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, 6020 Innsbruck, Austria
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16
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Kumar S, Lim J, Rivera N, Wong W, Ang YS, Ang LK, Wong LJ. Strongly correlated multielectron bunches from interaction with quantum light. SCIENCE ADVANCES 2024; 10:eadm9563. [PMID: 38718122 PMCID: PMC11078178 DOI: 10.1126/sciadv.adm9563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 04/04/2024] [Indexed: 05/12/2024]
Abstract
Strongly correlated electron systems are a cornerstone of modern physics, being responsible for groundbreaking phenomena from superconducting magnets to quantum computing. In most cases, correlations in electrons arise exclusively because of Coulomb interactions. In this work, we reveal that free electrons interacting simultaneously with a light field can become highly correlated via mechanisms beyond Coulomb interactions. In the case of two electrons, the resulting Pearson correlation coefficient for the joint probability distribution of the output electron energies is enhanced by more than 13 orders of magnitude compared to that of electrons interacting with the light field in succession (one after another). These highly correlated electrons are the result of momentum and energy exchange between the participating electrons via the external quantum light field. Our findings pave the way to the creation and control of highly correlated free electrons for applications including quantum information and ultrafast imaging.
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Affiliation(s)
- Suraj Kumar
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Jeremy Lim
- Science, Mathematics and Technology, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore
| | - Nicholas Rivera
- Department of Physics, Harvard University, Cambridge MA 02138, USA
| | - Wesley Wong
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Yee Sin Ang
- Science, Mathematics and Technology, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore
| | - Lay Kee Ang
- Science, Mathematics and Technology, Singapore University of Technology and Design, 8 Somapah Road, Singapore 487372, Singapore
| | - Liang Jie Wong
- School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore
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17
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Zhang HK, Liu S, Zhang SX. Absence of Barren Plateaus in Finite Local-Depth Circuits with Long-Range Entanglement. PHYSICAL REVIEW LETTERS 2024; 132:150603. [PMID: 38682974 DOI: 10.1103/physrevlett.132.150603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 01/24/2024] [Accepted: 03/13/2024] [Indexed: 05/01/2024]
Abstract
Ground state preparation is classically intractable for general Hamiltonians. On quantum devices, shallow parametrized circuits can be effectively trained to obtain short-range entangled states under the paradigm of variational quantum eigensolver, while deep circuits are generally untrainable due to the barren plateau phenomenon. In this Letter, we give a general lower bound on the variance of circuit gradients for arbitrary quantum circuits composed of local 2-designs. Based on our unified framework, we prove the absence of barren plateaus in training finite local-depth circuits (FLDC) for the ground states of local Hamiltonians. FLDCs are allowed to be deep in the conventional circuit depth to generate long-range entangled ground states, such as topologically ordered states, but their local depths are finite, i.e., there is only a finite number of gates acting on individual qubits. This characteristic sets FLDC apart from shallow circuits: FLDC in general cannot be classically simulated to estimate local observables efficiently by existing tensor network methods in two and higher dimensions. We validate our analytical results with extensive numerical simulations and demonstrate the effectiveness of variational training using the generalized toric code model.
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Affiliation(s)
- Hao-Kai Zhang
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
| | - Shuo Liu
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
| | - Shi-Xin Zhang
- Tencent Quantum Laboratory, Tencent, Shenzhen, Guangdong 518057, China
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18
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Unnikrishnan G, Ilzhöfer P, Scholz A, Hölzl C, Götzelmann A, Gupta RK, Zhao J, Krauter J, Weber S, Makki N, Büchler HP, Pfau T, Meinert F. Coherent Control of the Fine-Structure Qubit in a Single Alkaline-Earth Atom. PHYSICAL REVIEW LETTERS 2024; 132:150606. [PMID: 38682979 DOI: 10.1103/physrevlett.132.150606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/11/2024] [Indexed: 05/01/2024]
Abstract
We report on the first realization of a novel neutral atom qubit encoded in the spin-orbit coupled metastable states ^{3}P_{0} and ^{3}P_{2} of a single ^{88}Sr atom trapped in an optical tweezer. Raman coupling of the qubit states promises rapid single-qubit rotations on par with the fast Rydberg-mediated two-body gates. We demonstrate preparation, readout, and coherent control of the qubit. In addition to driving Rabi oscillations bridging an energy gap of more than 17 THz using a pair of phase-locked clock lasers, we also carry out Ramsey spectroscopy to extract the transverse qubit coherence time T_{2}. When the tweezer is tuned into magic trapping conditions, which is achieved in our setup by tuning the tensor polarizability of the ^{3}P_{2} state via an external control magnetic field, we measure T_{2}=1.2 ms. A microscopic quantum mechanical model is used to simulate our experiments including dominant noise sources. We identify the main constraints limiting the observed coherence time and project improvements to our system in the immediate future. Our Letter opens the door for a so-far-unexplored qubit encoding concept for neutral atom-based quantum computing.
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Affiliation(s)
- G Unnikrishnan
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - P Ilzhöfer
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - A Scholz
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - C Hölzl
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - A Götzelmann
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - R K Gupta
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J Zhao
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - J Krauter
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - S Weber
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - N Makki
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - H P Büchler
- Institute for Theoretical Physics III and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - T Pfau
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
| | - F Meinert
- 5. Physikalisches Institut and Center for Integrated Quantum Science and Technology, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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19
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Pucher S, Klüsener V, Spriestersbach F, Geiger J, Schindewolf A, Bloch I, Blatt S. Fine-Structure Qubit Encoded in Metastable Strontium Trapped in an Optical Lattice. PHYSICAL REVIEW LETTERS 2024; 132:150605. [PMID: 38682987 DOI: 10.1103/physrevlett.132.150605] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/11/2024] [Indexed: 05/01/2024]
Abstract
We demonstrate coherent control of the fine-structure qubit in neutral strontium atoms. This qubit is encoded in the metastable ^{3}P_{2} and ^{3}P_{0} states, coupled by a Raman transition. Using a magnetic quadrupole transition, we demonstrate coherent state initialization of this THz qubit. We show Rabi oscillations with more than 60 coherent cycles and single-qubit rotations on the μs scale. With spin echo, we demonstrate coherence times of tens of ms. Our results pave the way for fast quantum information processors and highly tunable quantum simulators with two-electron atoms.
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Affiliation(s)
- S Pucher
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology, 80799 München, Germany
| | - V Klüsener
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology, 80799 München, Germany
| | - F Spriestersbach
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology, 80799 München, Germany
| | - J Geiger
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology, 80799 München, Germany
| | - A Schindewolf
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology, 80799 München, Germany
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 80799 München, Germany
| | - I Bloch
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology, 80799 München, Germany
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 80799 München, Germany
| | - S Blatt
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology, 80799 München, Germany
- Fakultät für Physik, Ludwig-Maximilians-Universität München, 80799 München, Germany
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20
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Vilas NB, Robichaud P, Hallas C, Li GK, Anderegg L, Doyle JM. An optical tweezer array of ultracold polyatomic molecules. Nature 2024; 628:282-286. [PMID: 38570690 DOI: 10.1038/s41586-024-07199-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 02/13/2024] [Indexed: 04/05/2024]
Abstract
Polyatomic molecules have rich structural features that make them uniquely suited to applications in quantum information science1-3, quantum simulation4-6, ultracold chemistry7 and searches for physics beyond the standard model8-10. However, a key challenge is fully controlling both the internal quantum state and the motional degrees of freedom of the molecules. Here we demonstrate the creation of an optical tweezer array of individual polyatomic molecules, CaOH, with quantum control of their internal quantum state. The complex quantum structure of CaOH results in a non-trivial dependence of the molecules' behaviour on the tweezer light wavelength. We control this interaction and directly and non-destructively image individual molecules in the tweezer array with a fidelity greater than 90%. The molecules are manipulated at the single internal quantum state level, thus demonstrating coherent state control in a tweezer array. The platform demonstrated here will enable a variety of experiments using individual polyatomic molecules with arbitrary spatial arrangement.
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Affiliation(s)
- Nathaniel B Vilas
- Department of Physics, Harvard University, Cambridge, MA, USA.
- Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA.
| | - Paige Robichaud
- Department of Physics, Harvard University, Cambridge, MA, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Christian Hallas
- Department of Physics, Harvard University, Cambridge, MA, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Grace K Li
- Department of Physics, Harvard University, Cambridge, MA, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - Loïc Anderegg
- Department of Physics, Harvard University, Cambridge, MA, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
| | - John M Doyle
- Department of Physics, Harvard University, Cambridge, MA, USA
- Harvard-MIT Center for Ultracold Atoms, Cambridge, MA, USA
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21
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Mashhadi L, Shayeganrad G. Quadrupole excitation of atoms with tightly focused Laguerre-Gaussian beams. OPTICS EXPRESS 2024; 32:12127-12140. [PMID: 38571045 DOI: 10.1364/oe.500848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Accepted: 01/18/2024] [Indexed: 04/05/2024]
Abstract
This article investigates the quadrupole excitation of a trapped atom exposed to the tightly focused Laguerre-Gaussian (LG) beams with parallel and antiparallel spin angular momentum (SAM) and orbital angular momentum (OAM) under nonparaxial conditions. The Rabi frequency profile of allowed quadrupole transition channels, modified by SAM and OAM interaction, in the focal plane is provided. In the case of antiparallel SAM and OAM, the excitation probability undergoes substantial modification due to the considerable contribution of longitudinal intensity variations in tightly focused condition. The findings offer insights into controlling localized atom transition, including OAM transfer, with potential applications in qudit-based technologies.
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22
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Chae E, Choi J, Kim J. An elementary review on basic principles and developments of qubits for quantum computing. NANO CONVERGENCE 2024; 11:11. [PMID: 38498068 PMCID: PMC10948723 DOI: 10.1186/s40580-024-00418-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 03/04/2024] [Indexed: 03/19/2024]
Abstract
An elementary review on principles of qubits and their prospects for quantum computing is provided. Due to its rapid development, quantum computing has attracted considerable attention as a core technology for the next generation and has demonstrated its potential in simulations of exotic materials, molecular structures, and theoretical computer science. To achieve fully error-corrected quantum computers, building a logical qubit from multiple physical qubits is crucial. The number of physical qubits needed depends on their error rates, making error reduction in physical qubits vital. Numerous efforts to reduce errors are ongoing in both existing and emerging quantum systems. Here, the principle and development of qubits, as well as the current status of the field, are reviewed to provide information to researchers from various fields and give insights into this promising technology.
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Affiliation(s)
- Eunmi Chae
- Department of Physics, Korea University, Seoul , 02841, Republic of Korea.
| | - Joonhee Choi
- Department of Electrical Engineering, Stanford University, Stanford, CA, 94305, USA.
| | - Junki Kim
- SKKU Advanced Institute of Nanotechnology (SAINT) & Department of Nano Science and Technology, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
- Department of Nano Engineering, Sungkyunkwan University, Suwon, 16419, Republic of Korea.
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23
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Klimov PV, Bengtsson A, Quintana C, Bourassa A, Hong S, Dunsworth A, Satzinger KJ, Livingston WP, Sivak V, Niu MY, Andersen TI, Zhang Y, Chik D, Chen Z, Neill C, Erickson C, Grajales Dau A, Megrant A, Roushan P, Korotkov AN, Kelly J, Smelyanskiy V, Chen Y, Neven H. Optimizing quantum gates towards the scale of logical qubits. Nat Commun 2024; 15:2442. [PMID: 38499541 PMCID: PMC10948820 DOI: 10.1038/s41467-024-46623-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Accepted: 03/04/2024] [Indexed: 03/20/2024] Open
Abstract
A foundational assumption of quantum error correction theory is that quantum gates can be scaled to large processors without exceeding the error-threshold for fault tolerance. Two major challenges that could become fundamental roadblocks are manufacturing high-performance quantum hardware and engineering a control system that can reach its performance limits. The control challenge of scaling quantum gates from small to large processors without degrading performance often maps to non-convex, high-constraint, and time-dynamic control optimization over an exponentially expanding configuration space. Here we report on a control optimization strategy that can scalably overcome the complexity of such problems. We demonstrate it by choreographing the frequency trajectories of 68 frequency-tunable superconducting qubits to execute single- and two-qubit gates while mitigating computational errors. When combined with a comprehensive model of physical errors across our processor, the strategy suppresses physical error rates by ~3.7× compared with the case of no optimization. Furthermore, it is projected to achieve a similar performance advantage on a distance-23 surface code logical qubit with 1057 physical qubits. Our control optimization strategy solves a generic scaling challenge in a way that can be adapted to a variety of quantum operations, algorithms, and computing architectures.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Alexander N Korotkov
- Google AI, Mountain View, CA, USA
- Department of Electrical and Computer Engineering, University of California, Riverside, CA, USA
| | | | | | - Yu Chen
- Google AI, Mountain View, CA, USA
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24
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Ocola PL, Dimitrova I, Grinkemeyer B, Guardado-Sanchez E, Đorđević T, Samutpraphoot P, Vuletić V, Lukin MD. Control and Entanglement of Individual Rydberg Atoms near a Nanoscale Device. PHYSICAL REVIEW LETTERS 2024; 132:113601. [PMID: 38563952 DOI: 10.1103/physrevlett.132.113601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 05/10/2023] [Accepted: 01/23/2024] [Indexed: 04/04/2024]
Abstract
Coherent control of Rydberg atoms near dielectric surfaces is a major challenge due to the large sensitivity of Rydberg states to electric fields. We demonstrate coherent single-atom operations and two-qubit entanglement as close as 100 μm from a nanophotonic device. Using the individual atom control enabled by optical tweezers to study the spatial and temporal properties of the electric field from the surface, we employ dynamical decoupling techniques to characterize and cancel the electric-field noise with submicrosecond temporal resolution. We further use entanglement-assisted sensing to accurately map magnitude and direction of electric-field gradients on a micrometer scale. Our observations open a path for integration of Rydberg arrays with micro- and nanoscale devices for applications in quantum networking and quantum information science.
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Affiliation(s)
- Paloma L Ocola
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Ivana Dimitrova
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Brandon Grinkemeyer
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | | | - Tamara Đorđević
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | | | - Vladan Vuletić
- Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Mikhail D Lukin
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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25
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Fauseweh B. Quantum many-body simulations on digital quantum computers: State-of-the-art and future challenges. Nat Commun 2024; 15:2123. [PMID: 38459040 PMCID: PMC10923891 DOI: 10.1038/s41467-024-46402-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 02/14/2024] [Indexed: 03/10/2024] Open
Abstract
Simulating quantum many-body systems is a key application for emerging quantum processors. While analog quantum simulation has already demonstrated quantum advantage, its digital counterpart has recently become the focus of intense research interest due to the availability of devices that aim to realize general-purpose quantum computers. In this perspective, we give a selective overview of the currently pursued approaches, review the advances in digital quantum simulation by comparing non-variational with variational approaches and identify hardware and algorithmic challenges. Based on this review, the question arises: What are the most promising problems that can be tackled with digital quantum simulation? We argue that problems of a qualitative nature are much more suitable for near-term devices then approaches aiming purely for a quantitative accuracy improvement.
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Affiliation(s)
- Benedikt Fauseweh
- Institute for Software Technology, German Aerospace Center (DLR), Linder Höhe, 51147, Cologne, Germany.
- Department of Physics, TU Dortmund University, Otto-Hahn-Str. 4, 44227, Dortmund, Germany.
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26
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Vitale V, Mendes-Santos T, Rodriguez A, Dalmonte M. Topological Kolmogorov complexity and the Berezinskii-Kosterlitz-Thouless mechanism. Phys Rev E 2024; 109:034102. [PMID: 38632805 DOI: 10.1103/physreve.109.034102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 02/08/2024] [Indexed: 04/19/2024]
Abstract
Topology plays a fundamental role in our understanding of many-body physics, from vortices and solitons in classical field theory to phases and excitations in quantum matter. Topological phenomena are intimately connected to the distribution of information content that, differently from ordinary matter, is now governed by nonlocal degrees of freedom. However, a precise characterization of how topological effects govern the complexity of a many-body state, i.e., its partition function, is presently unclear. In this paper, we show how topology and complexity are directly intertwined concepts in the context of classical statistical mechanics. We concretely present a theory that shows how the Kolmogorov complexity of a classical partition function sampling carries unique, distinctive features depending on the presence of topological excitations in the system. We confront two-dimensional Ising, Heisenberg, and XY models on several topologies and study the corresponding samplings as high-dimensional manifolds in configuration space, quantifying their complexity via the intrinsic dimension. While for the Ising and Heisenberg models the intrinsic dimension is independent of the real-space topology, for the XY model it depends crucially on temperature: across the Berezkinskii-Kosterlitz-Thouless (BKT) transition, complexity becomes topology dependent. In the BKT phase, it displays a characteristic dependence on the homology of the real-space manifold, and, for g-torii, it follows a scaling that is solely genus dependent. We argue that this behavior is intimately connected to the emergence of an order parameter in data space, the conditional connectivity, which displays scaling behavior. Our approach paves the way for an understanding of topological phenomena emergent from many-body interactions from the perspective of Kolmogorov complexity.
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Affiliation(s)
- Vittorio Vitale
- International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34151 Trieste, Italy
- SISSA, via Bonomea 265, 34136 Trieste, Italy
- Université Grenoble Alpes, CNRS, Laboratoire de Physique et Modélisation des Milieux Condensés (LPMMC), Grenoble 38000, France
| | - Tiago Mendes-Santos
- Theoretical Physics III, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, 86135 Augsburg, Germany
| | - Alex Rodriguez
- International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34151 Trieste, Italy
- Dipartimento di Matematica e Geoscienze, Universitá degli Studi di Trieste, via Alfonso Valerio 12/1, 34127, Trieste, Italy
| | - Marcello Dalmonte
- International Centre for Theoretical Physics (ICTP), Strada Costiera 11, 34151 Trieste, Italy
- SISSA, via Bonomea 265, 34136 Trieste, Italy
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27
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Li Z, Roy T, Rodríguez Pérez D, Lee KH, Kapit E, Schuster DI. Autonomous error correction of a single logical qubit using two transmons. Nat Commun 2024; 15:1681. [PMID: 38395989 PMCID: PMC10891116 DOI: 10.1038/s41467-024-45858-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Large-scale quantum computers will inevitably need quantum error correction to protect information against decoherence. Traditional error correction typically requires many qubits, along with high-efficiency error syndrome measurement and real-time feedback. Autonomous quantum error correction instead uses steady-state bath engineering to perform the correction in a hardware-efficient manner. In this work, we develop a new autonomous quantum error correction scheme that actively corrects single-photon loss and passively suppresses low-frequency dephasing, and we demonstrate an important experimental step towards its full implementation with transmons. Compared to uncorrected encoding, improvements are experimentally witnessed for the logical zero, one, and superposition states. Our results show the potential of implementing hardware-efficient autonomous quantum error correction to enhance the reliability of a transmon-based quantum information processor.
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Affiliation(s)
- Ziqian Li
- James Franck Institute, University of Chicago, Chicago, IL, 60637, USA
- Department of Physics, University of Chicago, Chicago, IL, 60637, USA
- Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA
| | - Tanay Roy
- James Franck Institute, University of Chicago, Chicago, IL, 60637, USA
- Department of Physics, University of Chicago, Chicago, IL, 60637, USA
| | | | - Kan-Heng Lee
- James Franck Institute, University of Chicago, Chicago, IL, 60637, USA
- Department of Physics, University of Chicago, Chicago, IL, 60637, USA
| | - Eliot Kapit
- Department of Physics, Colorado School of Mines, Golden, CO, 80401, USA
| | - David I Schuster
- James Franck Institute, University of Chicago, Chicago, IL, 60637, USA.
- Department of Physics, University of Chicago, Chicago, IL, 60637, USA.
- Department of Applied Physics, Stanford University, Stanford, CA, 94305, USA.
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA.
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28
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Jackson A, Kapourniotis T, Datta A. Accreditation of analogue quantum simulators. Proc Natl Acad Sci U S A 2024; 121:e2309627121. [PMID: 38294940 PMCID: PMC10861924 DOI: 10.1073/pnas.2309627121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 12/05/2023] [Indexed: 02/02/2024] Open
Abstract
We present an accreditation protocol for analogue, i.e., continuous-time, quantum simulators. For a given simulation task, it provides an upper bound on the variation distance between the probability distributions at the output of an erroneous and error-free analogue quantum simulator. As its overheads are independent of the size and nature of the simulation, the protocol is ready for immediate usage and practical for the long term. It builds on the recent theoretical advances of strongly universal Hamiltonians and quantum accreditation as well as experimental progress toward the realization of programmable hybrid analogue-digital quantum simulators.
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Affiliation(s)
- Andrew Jackson
- Department of Physics, University of Warwick, CoventryCV4 7AL, United Kingdom
| | | | - Animesh Datta
- Department of Physics, University of Warwick, CoventryCV4 7AL, United Kingdom
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29
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Tian Z, Chang H, Lv X, Yang M, Wang Z, Yang P, Zhang P, Li G, Zhang T. Resolved Raman sideband cooling of a single optically trapped cesium atom. OPTICS LETTERS 2024; 49:542-545. [PMID: 38300054 DOI: 10.1364/ol.514160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Accepted: 01/01/2024] [Indexed: 02/02/2024]
Abstract
We developed a resolved Raman sideband cooling scheme that can efficiently prepare a single optically trapped cesium (Cs) atom in its motional ground states. A two-photon Raman process between two outermost Zeeman sublevels in a single hyperfine state is applied to reduce the phonon number. Our scheme is less sensitive to the variation in the magnetic field than the commonly used scheme where the two outermost Zeeman sublevels belonging to the two separate ground hyperfine states are taken. Fast optical pumping with less spontaneous emission guarantees the efficiency of the cooling process. After cooling for 50 ms, 82% of the Cs atoms populate their three-dimensional ground states. Our scheme improves the long-term stability of Raman sideband cooling in the presence of magnetic field drift and is thus suitable for cooling other trapped atoms or ions with abundant magnetic sublevels.
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30
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Bluvstein D, Evered SJ, Geim AA, Li SH, Zhou H, Manovitz T, Ebadi S, Cain M, Kalinowski M, Hangleiter D, Bonilla Ataides JP, Maskara N, Cong I, Gao X, Sales Rodriguez P, Karolyshyn T, Semeghini G, Gullans MJ, Greiner M, Vuletić V, Lukin MD. Logical quantum processor based on reconfigurable atom arrays. Nature 2024; 626:58-65. [PMID: 38056497 PMCID: PMC10830422 DOI: 10.1038/s41586-023-06927-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 12/01/2023] [Indexed: 12/08/2023]
Abstract
Suppressing errors is the central challenge for useful quantum computing1, requiring quantum error correction (QEC)2-6 for large-scale processing. However, the overhead in the realization of error-corrected 'logical' qubits, in which information is encoded across many physical qubits for redundancy2-4, poses substantial challenges to large-scale logical quantum computing. Here we report the realization of a programmable quantum processor based on encoded logical qubits operating with up to 280 physical qubits. Using logical-level control and a zoned architecture in reconfigurable neutral-atom arrays7, our system combines high two-qubit gate fidelities8, arbitrary connectivity7,9, as well as fully programmable single-qubit rotations and mid-circuit readout10-15. Operating this logical processor with various types of encoding, we demonstrate improvement of a two-qubit logic gate by scaling surface-code6 distance from d = 3 to d = 7, preparation of colour-code qubits with break-even fidelities5, fault-tolerant creation of logical Greenberger-Horne-Zeilinger (GHZ) states and feedforward entanglement teleportation, as well as operation of 40 colour-code qubits. Finally, using 3D [[8,3,2]] code blocks16,17, we realize computationally complex sampling circuits18 with up to 48 logical qubits entangled with hypercube connectivity19 with 228 logical two-qubit gates and 48 logical CCZ gates20. We find that this logical encoding substantially improves algorithmic performance with error detection, outperforming physical-qubit fidelities at both cross-entropy benchmarking and quantum simulations of fast scrambling21,22. These results herald the advent of early error-corrected quantum computation and chart a path towards large-scale logical processors.
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Affiliation(s)
- Dolev Bluvstein
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Simon J Evered
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | - Sophie H Li
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Hengyun Zhou
- Department of Physics, Harvard University, Cambridge, MA, USA
- QuEra Computing Inc., Boston, MA, USA
| | - Tom Manovitz
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Sepehr Ebadi
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Madelyn Cain
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | - Dominik Hangleiter
- Joint Center for Quantum Information and Computer Science, NIST/University of Maryland, College Park, MD, USA
| | | | - Nishad Maskara
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Iris Cong
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Xun Gao
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | | | - Giulia Semeghini
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Michael J Gullans
- Joint Center for Quantum Information and Computer Science, NIST/University of Maryland, College Park, MD, USA
| | - Markus Greiner
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Vladan Vuletić
- Department of Physics and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mikhail D Lukin
- Department of Physics, Harvard University, Cambridge, MA, USA.
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31
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Liu H, Wang J, Chen S, Sun Z, Xu H, Han Y, Wang C, Liu H, Huang L, Luo J, Liu D. Direct Visualization of Dark Interlayer Exciton Transport in Moiré Superlattices. NANO LETTERS 2024; 24:339-346. [PMID: 38147355 DOI: 10.1021/acs.nanolett.3c04105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2023]
Abstract
Moiré superlattices have emerged as an unprecedented manipulation tool for engineering correlated quantum phenomena in van der Waals heterostructures. With moiré potentials as a naturally configurable solid-state that sustains high exciton density, interlayer excitons in transition metal dichalcogenide heterostructures are expected to achieve high-temperature exciton condensation. However, the exciton degeneracy state is usually optically inactive due to the finite momentum of interlayer excitons. Experimental observation of dark interlayer excitons in moiré potentials remains challenging. Here we directly visualize the dark interlayer exciton transport in WS2/h-BN/WSe2 heterostructures using femtosecond transient absorption microscopy. We observe a transition from classical free exciton gas to quantum degeneracy by imaging temperature-dependent exciton transport. Below a critical degeneracy temperature, exciton diffusion rates exhibit an accelerating downward trend, which can be explained well by a nonlinear quantum diffusion model. These results open the door to quantum information processing and high-precision metrology in moiré superlattices.
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Affiliation(s)
- Huan Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Jiangcai Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Shihong Chen
- School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China
| | - Zejun Sun
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Haowen Xu
- Institute for Advanced Materials and Technology, University of Science and Technology Beijing, Beijing 100083, China
| | - Yishu Han
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Chong Wang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Huixian Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Li Huang
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Jianbin Luo
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
| | - Dameng Liu
- State Key Laboratory of Tribology, Tsinghua University, Beijing 100084, China
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32
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Zhu GY, Tantivasadakarn N, Vishwanath A, Trebst S, Verresen R. Nishimori's Cat: Stable Long-Range Entanglement from Finite-Depth Unitaries and Weak Measurements. PHYSICAL REVIEW LETTERS 2023; 131:200201. [PMID: 38039472 DOI: 10.1103/physrevlett.131.200201] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/25/2023] [Indexed: 12/03/2023]
Abstract
In the field of monitored quantum circuits, it has remained an open question whether finite-time protocols for preparing long-range entangled states lead to phases of matter that are stable to gate imperfections, that can convert projective into weak measurements. Here, we show that in certain cases, long-range entanglement persists in the presence of weak measurements, and gives rise to novel forms of quantum criticality. We demonstrate this explicitly for preparing the two-dimensional Greenberger-Horne-Zeilinger cat state and the three-dimensional toric code as minimal instances. In contrast to random monitored circuits, our circuit of gates and measurements is deterministic; the only randomness is in the measurement outcomes. We show how the randomness in these weak measurements allows us to track the solvable Nishimori line of the random-bond Ising model, rigorously establishing the stability of the glassy long-range entangled states in two and three spatial dimensions. Away from this exactly solvable construction, we use hybrid tensor network and Monte Carlo simulations to obtain a nonzero Edwards-Anderson order parameter as an indicator of long-range entanglement in the two-dimensional scenario. We argue that our protocol admits a natural implementation in existing quantum computing architectures, requiring only a depth-3 circuit on IBM's heavy-hexagon transmon chips.
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Affiliation(s)
- Guo-Yi Zhu
- Institute for Theoretical Physics, University of Cologne, Zülpicher Straße 77, 50937 Cologne, Germany
| | - Nathanan Tantivasadakarn
- Walter Burke Institute for Theoretical Physics and Department of Physics, California Institute of Technology, Pasadena, California 91125, USA
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Ashvin Vishwanath
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Simon Trebst
- Institute for Theoretical Physics, University of Cologne, Zülpicher Straße 77, 50937 Cologne, Germany
- Center for Computational Quantum Physics, Flatiron Institute, 162 5th Avenue, New York, New York 10010, USA
| | - Ruben Verresen
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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33
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Zhao L, Lee MDK, Aliyu MM, Loh H. Floquet-tailored Rydberg interactions. Nat Commun 2023; 14:7128. [PMID: 37932268 PMCID: PMC10628180 DOI: 10.1038/s41467-023-42899-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 10/25/2023] [Indexed: 11/08/2023] Open
Abstract
The Rydberg blockade is a key ingredient for entangling atoms in arrays. However, it requires atoms to be spaced well within the blockade radius, which limits the range of local quantum gates. Here we break this constraint using Floquet frequency modulation, with which we demonstrate Rydberg-blockade entanglement beyond the traditional blockade radius and show how the enlarged entanglement range improves qubit connectivity in a neutral atom array. Further, we find that the coherence of entangled states can be extended under Floquet frequency modulation. Finally, we realize Rydberg anti-blockade states for two sodium Rydberg atoms within the blockade radius. Such Rydberg anti-blockade states for atoms at close range enables the robust preparation of strongly-interacting, long-lived Rydberg states, yet their steady-state population cannot be achieved with only the conventional static drive. Our work transforms between the paradigmatic regimes of Rydberg blockade versus anti-blockade and paves the way for realizing more connected, coherent, and tunable neutral atom quantum processors with a single approach.
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Affiliation(s)
- Luheng Zhao
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore
| | - Michael Dao Kang Lee
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore
| | - Mohammad Mujahid Aliyu
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore
| | - Huanqian Loh
- Centre for Quantum Technologies, National University of Singapore, 117543, Singapore, Singapore.
- Department of Physics, National University of Singapore, 117542, Singapore, Singapore.
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34
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Cesa F, Pichler H. Universal Quantum Computation in Globally Driven Rydberg Atom Arrays. PHYSICAL REVIEW LETTERS 2023; 131:170601. [PMID: 37955503 DOI: 10.1103/physrevlett.131.170601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 09/27/2023] [Indexed: 11/14/2023]
Abstract
We develop a model for quantum computation with Rydberg atom arrays, which only relies on global driving, without the need of local addressing of the qubits: any circuit is executed by a sequence of global, resonant laser pulses on a static atomic arrangement. We present two constructions: for the first, the circuit is imprinted in the trap positions of the atoms and executed by the pulses; for the second, the atom arrangement is circuit-independent, and the algorithm is entirely encoded in the global driving sequence. Our results show in particular that a quadratic overhead in atom number is sufficient to eliminate the need for local control to realize a universal quantum processor. We give explicit protocols for all steps of an arbitrary quantum computation, and discuss strategies for error suppression specific to our model. Our scheme is based on dual-species processors with atoms subjected to Rydberg blockade constraints, but it might be transposed to other setups as well.
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Affiliation(s)
- Francesco Cesa
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Innsbruck A-6020, Austria
- Department of Physics, University of Trieste, Strada Costiera 11, 34151 Trieste, Italy
- Istituto Nazionale di Fisica Nucleare, Trieste Section, Via Valerio 2, 34127 Trieste, Italy
| | - Hannes Pichler
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Innsbruck A-6020, Austria
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35
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Ma S, Liu G, Peng P, Zhang B, Jandura S, Claes J, Burgers AP, Pupillo G, Puri S, Thompson JD. High-fidelity gates and mid-circuit erasure conversion in an atomic qubit. Nature 2023; 622:279-284. [PMID: 37821593 DOI: 10.1038/s41586-023-06438-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Accepted: 07/14/2023] [Indexed: 10/13/2023]
Abstract
The development of scalable, high-fidelity qubits is a key challenge in quantum information science. Neutral atom qubits have progressed rapidly in recent years, demonstrating programmable processors1,2 and quantum simulators with scaling to hundreds of atoms3,4. Exploring new atomic species, such as alkaline earth atoms5-7, or combining multiple species8 can provide new paths to improving coherence, control and scalability. For example, for eventual application in quantum error correction, it is advantageous to realize qubits with structured error models, such as biased Pauli errors9 or conversion of errors into detectable erasures10. Here we demonstrate a new neutral atom qubit using the nuclear spin of a long-lived metastable state in 171Yb. The long coherence time and fast excitation to the Rydberg state allow one- and two-qubit gates with fidelities of 0.9990(1) and 0.980(1), respectively. Importantly, a large fraction of all gate errors result in decays out of the qubit subspace to the ground state. By performing fast, mid-circuit detection of these errors, we convert them into erasure errors; during detection, the induced error probability on qubits remaining in the computational space is less than 10-5. This work establishes metastable 171Yb as a promising platform for realizing fault-tolerant quantum computing.
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Affiliation(s)
- Shuo Ma
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA
- Department of Physics, Princeton University, Princeton, NJ, USA
| | - Genyue Liu
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA
| | - Pai Peng
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA
| | - Bichen Zhang
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA
| | - Sven Jandura
- University of Strasbourg and CNRS, CESQ and ISIS (UMR 7006), aQCess, Strasbourg, France
| | - Jahan Claes
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - Alex P Burgers
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA
- Department of Electrical and Computer Engineering, College of Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Guido Pupillo
- University of Strasbourg and CNRS, CESQ and ISIS (UMR 7006), aQCess, Strasbourg, France
| | - Shruti Puri
- Department of Applied Physics, Yale University, New Haven, CT, USA
- Yale Quantum Institute, Yale University, New Haven, CT, USA
| | - Jeff D Thompson
- Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA.
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36
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Evered SJ, Bluvstein D, Kalinowski M, Ebadi S, Manovitz T, Zhou H, Li SH, Geim AA, Wang TT, Maskara N, Levine H, Semeghini G, Greiner M, Vuletić V, Lukin MD. High-fidelity parallel entangling gates on a neutral-atom quantum computer. Nature 2023; 622:268-272. [PMID: 37821591 PMCID: PMC10567572 DOI: 10.1038/s41586-023-06481-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 07/25/2023] [Indexed: 10/13/2023]
Abstract
The ability to perform entangling quantum operations with low error rates in a scalable fashion is a central element of useful quantum information processing1. Neutral-atom arrays have recently emerged as a promising quantum computing platform, featuring coherent control over hundreds of qubits2,3 and any-to-any gate connectivity in a flexible, dynamically reconfigurable architecture4. The main outstanding challenge has been to reduce errors in entangling operations mediated through Rydberg interactions5. Here we report the realization of two-qubit entangling gates with 99.5% fidelity on up to 60 atoms in parallel, surpassing the surface-code threshold for error correction6,7. Our method uses fast, single-pulse gates based on optimal control8, atomic dark states to reduce scattering9 and improvements to Rydberg excitation and atom cooling. We benchmark fidelity using several methods based on repeated gate applications10,11, characterize the physical error sources and outline future improvements. Finally, we generalize our method to design entangling gates involving a higher number of qubits, which we demonstrate by realizing low-error three-qubit gates12,13. By enabling high-fidelity operation in a scalable, highly connected system, these advances lay the groundwork for large-scale implementation of quantum algorithms14, error-corrected circuits7 and digital simulations15.
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Affiliation(s)
- Simon J Evered
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Dolev Bluvstein
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | - Sepehr Ebadi
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Tom Manovitz
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Hengyun Zhou
- Department of Physics, Harvard University, Cambridge, MA, USA
- QuEra Computing Inc., Boston, MA, USA
| | - Sophie H Li
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | - Tout T Wang
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Nishad Maskara
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Harry Levine
- Department of Physics, Harvard University, Cambridge, MA, USA
- AWS Center for Quantum Computing, Pasadena, CA, USA
| | - Giulia Semeghini
- Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | - Markus Greiner
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Vladan Vuletić
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA
- Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Mikhail D Lukin
- Department of Physics, Harvard University, Cambridge, MA, USA.
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37
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Eckner WJ, Darkwah Oppong N, Cao A, Young AW, Milner WR, Robinson JM, Ye J, Kaufman AM. Realizing spin squeezing with Rydberg interactions in an optical clock. Nature 2023; 621:734-739. [PMID: 37648865 DOI: 10.1038/s41586-023-06360-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 06/22/2023] [Indexed: 09/01/2023]
Abstract
Neutral-atom arrays trapped in optical potentials are a powerful platform for studying quantum physics, combining precise single-particle control and detection with a range of tunable entangling interactions1-3. For example, these capabilities have been leveraged for state-of-the-art frequency metrology4,5 as well as microscopic studies of entangled many-particle states6-11. Here we combine these applications to realize spin squeezing-a widely studied operation for producing metrologically useful entanglement-in an optical atomic clock based on a programmable array of interacting optical qubits. In this demonstration of Rydberg-mediated squeezing with a neutral-atom optical clock, we generate states that have almost four decibels of metrological gain. In addition, we perform a synchronous frequency comparison between independent squeezed states and observe a fractional-frequency stability of 1.087(1) × 10-15 at one-second averaging time, which is 1.94(1) decibels below the standard quantum limit and reaches a fractional precision at the 10-17 level during a half-hour measurement. We further leverage the programmable control afforded by optical tweezer arrays to apply local phase shifts to explore spin squeezing in measurements that operate beyond the relative coherence time with the optical local oscillator. The realization of this spin-squeezing protocol in a programmable atom-array clock will enable a wide range of quantum-information-inspired techniques for optimal phase estimation and Heisenberg-limited optical atomic clocks12-16.
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Affiliation(s)
- William J Eckner
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - Nelson Darkwah Oppong
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - Alec Cao
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - Aaron W Young
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - William R Milner
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - John M Robinson
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - Jun Ye
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado, USA
| | - Adam M Kaufman
- JILA, University of Colorado and National Institute of Standards and Technology, and Department of Physics, University of Colorado, Boulder, Colorado, USA.
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38
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Magoni M, Joshi R, Lesanovsky I. Molecular Dynamics in Rydberg Tweezer Arrays: Spin-Phonon Entanglement and Jahn-Teller Effect. PHYSICAL REVIEW LETTERS 2023; 131:093002. [PMID: 37721842 DOI: 10.1103/physrevlett.131.093002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 08/07/2023] [Accepted: 08/15/2023] [Indexed: 09/20/2023]
Abstract
Atoms confined in optical tweezer arrays constitute a platform for the implementation of quantum computers and simulators. State-dependent operations are realized by exploiting electrostatic dipolar interactions that emerge, when two atoms are simultaneously excited to high-lying electronic states, so-called Rydberg states. These interactions also lead to state-dependent mechanical forces, which couple the electronic dynamics of the atoms to their vibrational motion. We explore these vibronic couplings within an artificial molecular system in which Rydberg states are excited under so-called facilitation conditions. This system, which is not necessarily self-bound, undergoes a structural transition between an equilateral triangle and an equal-weighted superposition of distorted triangular states (Jahn-Teller regime) exhibiting spin-phonon entanglement on a micrometer distance. This highlights the potential of Rydberg tweezer arrays for the study of molecular phenomena at exaggerated length scales.
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Affiliation(s)
- Matteo Magoni
- Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany
| | - Radhika Joshi
- Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany
| | - Igor Lesanovsky
- Institut für Theoretische Physik, Universität Tübingen, Auf der Morgenstelle 14, 72076 Tübingen, Germany
- School of Physics and Astronomy and Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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39
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González-Cuadra D, Bluvstein D, Kalinowski M, Kaubruegger R, Maskara N, Naldesi P, Zache TV, Kaufman AM, Lukin MD, Pichler H, Vermersch B, Ye J, Zoller P. Fermionic quantum processing with programmable neutral atom arrays. Proc Natl Acad Sci U S A 2023; 120:e2304294120. [PMID: 37607226 PMCID: PMC10468619 DOI: 10.1073/pnas.2304294120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 07/26/2023] [Indexed: 08/24/2023] Open
Abstract
Simulating the properties of many-body fermionic systems is an outstanding computational challenge relevant to material science, quantum chemistry, and particle physics.-5.4pc]Please note that the spelling of the following author names in the manuscript differs from the spelling provided in the article metadata: D. González-Cuadra, D. Bluvstein, M. Kalinowski, R. Kaubruegger, N. Maskara, P. Naldesi, T. V. Zache, A. M. Kaufman, M. D. Lukin, H. Pichler, B. Vermersch, Jun Ye, and P. Zoller. The spelling provided in the manuscript has been retained; please confirm. Although qubit-based quantum computers can potentially tackle this problem more efficiently than classical devices, encoding nonlocal fermionic statistics introduces an overhead in the required resources, limiting their applicability on near-term architectures. In this work, we present a fermionic quantum processor, where fermionic models are locally encoded in a fermionic register and simulated in a hardware-efficient manner using fermionic gates. We consider in particular fermionic atoms in programmable tweezer arrays and develop different protocols to implement nonlocal gates, guaranteeing Fermi statistics at the hardware level. We use this gate set, together with Rydberg-mediated interaction gates, to find efficient circuit decompositions for digital and variational quantum simulation algorithms, illustrated here for molecular energy estimation. Finally, we consider a combined fermion-qubit architecture, where both the motional and internal degrees of freedom of the atoms are harnessed to efficiently implement quantum phase estimation as well as to simulate lattice gauge theory dynamics.
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Affiliation(s)
- D. González-Cuadra
- Institute for Theoretical Physics, University of Innsbruck, 6020Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020Innsbruck, Austria
| | - D. Bluvstein
- Department of Physics, Harvard University, Cambridge, MA02138
| | - M. Kalinowski
- Department of Physics, Harvard University, Cambridge, MA02138
| | - R. Kaubruegger
- Institute for Theoretical Physics, University of Innsbruck, 6020Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020Innsbruck, Austria
| | - N. Maskara
- Department of Physics, Harvard University, Cambridge, MA02138
| | - P. Naldesi
- Institute for Theoretical Physics, University of Innsbruck, 6020Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020Innsbruck, Austria
| | - T. V. Zache
- Institute for Theoretical Physics, University of Innsbruck, 6020Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020Innsbruck, Austria
| | - A. M. Kaufman
- Department of Physics, University of Colorado, Boulder, CO80309
- Joint Institute for Laboratory Astrophysics, University of Colorado and National Institute of Standards and Technology, Boulder, CO80309
| | - M. D. Lukin
- Department of Physics, Harvard University, Cambridge, MA02138
| | - H. Pichler
- Institute for Theoretical Physics, University of Innsbruck, 6020Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020Innsbruck, Austria
| | - B. Vermersch
- Institute for Theoretical Physics, University of Innsbruck, 6020Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020Innsbruck, Austria
- Université Grenoble Alpes, CNRS, Laboratoire de Physique et Modélisation des Milieux Condensés, Grenoble38000, France
| | - Jun Ye
- Department of Physics, University of Colorado, Boulder, CO80309
- Joint Institute for Laboratory Astrophysics, University of Colorado and National Institute of Standards and Technology, Boulder, CO80309
| | - P. Zoller
- Institute for Theoretical Physics, University of Innsbruck, 6020Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, 6020Innsbruck, Austria
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40
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Zhang WY, He MG, Sun H, Zheng YG, Liu Y, Luo A, Wang HY, Zhu ZH, Qiu PY, Shen YC, Wang XK, Lin W, Yu ST, Li BC, Xiao B, Li MD, Yang YM, Jiang X, Dai HN, Zhou Y, Ma X, Yuan ZS, Pan JW. Scalable Multipartite Entanglement Created by Spin Exchange in an Optical Lattice. PHYSICAL REVIEW LETTERS 2023; 131:073401. [PMID: 37656862 DOI: 10.1103/physrevlett.131.073401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 06/30/2023] [Indexed: 09/03/2023]
Abstract
Ultracold atoms in optical lattices form a competitive candidate for quantum computation owing to the excellent coherence properties, the highly parallel operations over spins, and the ultralow entropy achieved in qubit arrays. For this, a massive number of parallel entangled atom pairs have been realized in superlattices. However, the more formidable challenge is to scale up and detect multipartite entanglement, the basic resource for quantum computation, due to the lack of manipulations over local atomic spins in retroreflected bichromatic superlattices. In this Letter, we realize the functional building blocks in quantum-gate-based architecture by developing a cross-angle spin-dependent optical superlattice for implementing layers of quantum gates over moderately separated atoms incorporated with a quantum gas microscope for single-atom manipulation and detection. Bell states with a fidelity of 95.6(5)% and a lifetime of 2.20±0.13 s are prepared in parallel, and then connected to multipartite entangled states of one-dimensional ten-atom chains and two-dimensional plaquettes of 2×4 atoms. The multipartite entanglement is further verified with full bipartite nonseparability criteria. This offers a new platform toward scalable quantum computation and simulation.
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Affiliation(s)
- Wei-Yong Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ming-Gen He
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Hui Sun
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yong-Guang Zheng
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ying Liu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - An Luo
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Han-Yi Wang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Zi-Hang Zhu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Pei-Yue Qiu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Ying-Chao Shen
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xuan-Kai Wang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Wan Lin
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Song-Tao Yu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Bin-Chen Li
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Bo Xiao
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Meng-Da Li
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Yu-Meng Yang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Xiao Jiang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Han-Ning Dai
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - You Zhou
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- Key Laboratory for Information Science of Electromagnetic Waves (Ministry of Education), Fudan University, Shanghai 200433, China
| | - Xiongfeng Ma
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Zhen-Sheng Yuan
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
| | - Jian-Wei Pan
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, University of Science and Technology of China, Hefei 230088, China
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41
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Naldesi P, Elben A, Minguzzi A, Clément D, Zoller P, Vermersch B. Fermionic Correlation Functions from Randomized Measurements in Programmable Atomic Quantum Devices. PHYSICAL REVIEW LETTERS 2023; 131:060601. [PMID: 37625073 DOI: 10.1103/physrevlett.131.060601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Accepted: 03/16/2023] [Indexed: 08/27/2023]
Abstract
We provide an efficient randomized measurement protocol to estimate two- and four-point fermionic correlations in ultracold atom experiments. Our approach is based on combining random atomic beam splitter operations, which can be realized with programmable optical landscapes, with high-resolution imaging systems such as quantum gas microscopes. We illustrate our results in the context of the variational quantum eigensolver algorithm for solving quantum chemistry problems.
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Affiliation(s)
- Piero Naldesi
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria
| | - Andreas Elben
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria
- Institute for Quantum Information and Matter, Caltech, Pasadena, California 91125, USA
- Walter Burke Institute for Theoretical Physics, Caltech, Pasadena, California 91125, USA
| | - Anna Minguzzi
- Univ. Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
| | - David Clément
- Université Paris-Saclay, Institut d'Optique Graduate School, CNRS, Laboratoire Charles Fabry, 91127, Palaiseau, France
| | - Peter Zoller
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria
| | - Benoît Vermersch
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck A-6020, Austria
- Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, Innsbruck A-6020, Austria
- Univ. Grenoble Alpes, CNRS, LPMMC, 38000 Grenoble, France
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42
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Wang HY, Zhang WY, Yao Z, Liu Y, Zhu ZH, Zheng YG, Wang XK, Zhai H, Yuan ZS, Pan JW. Interrelated Thermalization and Quantum Criticality in a Lattice Gauge Simulator. PHYSICAL REVIEW LETTERS 2023; 131:050401. [PMID: 37595229 DOI: 10.1103/physrevlett.131.050401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 06/22/2023] [Indexed: 08/20/2023]
Abstract
Gauge theory and thermalization are both topics of essential importance for modern quantum science and technology. The recently realized atomic quantum simulator for lattice gauge theories provides a unique opportunity for studying thermalization in gauge theory, in which theoretical studies have shown that quantum thermalization can signal the quantum phase transition. Nevertheless, the experimental study remains a challenge to accurately determine the critical point and controllably explore the thermalization dynamics due to the lack of techniques for locally manipulating and detecting matter and gauge fields. We report an experimental investigation of the quantum criticality in the lattice gauge theory from both equilibrium and nonequilibrium thermalization perspectives, with the help of the single-site addressing and atom-number-resolved detection capabilities. We accurately determine the quantum critical point and observe that the Néel state thermalizes only in the critical regime. This result manifests the interplay between quantum many-body scars, quantum criticality, and symmetry breaking.
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Affiliation(s)
- Han-Yi Wang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Wei-Yong Zhang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Zhiyuan Yao
- Key Laboratory of Quantum Theory and Applications of MoE, Lanzhou Center for Theoretical Physics, and Key Laboratory of Theoretical Physics of Gansu Province, Lanzhou University, Lanzhou, Gansu 730000, China
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
| | - Ying Liu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Zi-Hang Zhu
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Yong-Guang Zheng
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Xuan-Kai Wang
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
| | - Hui Zhai
- Institute for Advanced Study, Tsinghua University, Beijing 100084, China
- Hefei National Laboratory, Hefei 230088, China
| | - Zhen-Sheng Yuan
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, Hefei 230088, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - Jian-Wei Pan
- Hefei National Research Center for Physical Sciences at the Microscale and School of Physical Sciences, University of Science and Technology of China, Hefei 230026, China
- Hefei National Laboratory, Hefei 230088, China
- CAS Center for Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
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43
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Nikolov B, Diamond-Hitchcock E, Bass J, Spong NLR, Pritchard JD. Randomized Benchmarking Using Nondestructive Readout in a Two-Dimensional Atom Array. PHYSICAL REVIEW LETTERS 2023; 131:030602. [PMID: 37540850 DOI: 10.1103/physrevlett.131.030602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 06/22/2023] [Indexed: 08/06/2023]
Abstract
Neutral atoms are a promising platform for scalable quantum computing, however, prior demonstration of high fidelity gates or low-loss readout methods have employed restricted numbers of qubits. Using randomized benchmarking of microwave-driven single-qubit gates, we demonstrate average gate errors of 7(2)×10^{-5} on a 225 site atom array using conventional, destructive readout. We further demonstrate a factor of 1.7 suppression of the primary measurement errors via low-loss, nondestructive, and state-selective readout on 49 sites while achieving gate errors of 2(9)×10^{-4}.
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Affiliation(s)
- B Nikolov
- Department of Physics and SUPA, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - E Diamond-Hitchcock
- Department of Physics and SUPA, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - J Bass
- Department of Physics and SUPA, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - N L R Spong
- Department of Physics and SUPA, University of Strathclyde, Glasgow G4 0NG, United Kingdom
| | - J D Pritchard
- Department of Physics and SUPA, University of Strathclyde, Glasgow G4 0NG, United Kingdom
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44
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Steinert LM, Osterholz P, Eberhard R, Festa L, Lorenz N, Chen Z, Trautmann A, Gross C. Spatially Tunable Spin Interactions in Neutral Atom Arrays. PHYSICAL REVIEW LETTERS 2023; 130:243001. [PMID: 37390432 DOI: 10.1103/physrevlett.130.243001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 01/20/2023] [Accepted: 05/16/2023] [Indexed: 07/02/2023]
Abstract
Analog quantum simulations with Rydberg atoms in optical tweezers routinely address strongly correlated many-body problems due to the hardware-efficient implementation of the Hamiltonian. Yet, their generality is limited, and flexible Hamiltonian-design techniques are needed to widen the scope of these simulators. Here we report on the realization of spatially tunable interactions for XYZ models implemented by two-color near-resonant coupling to Rydberg pair states. Our results demonstrate the unique opportunities of Rydberg dressing for Hamiltonian design in analog quantum simulators.
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Affiliation(s)
- Lea-Marina Steinert
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
- Physikalisches Institut, Eberhard Karls Universität Tübingen, 72076 Tübingen, Germany
| | - Philip Osterholz
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
- Physikalisches Institut, Eberhard Karls Universität Tübingen, 72076 Tübingen, Germany
| | - Robin Eberhard
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Lorenzo Festa
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Nikolaus Lorenz
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Zaijun Chen
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
| | - Arno Trautmann
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
- Physikalisches Institut, Eberhard Karls Universität Tübingen, 72076 Tübingen, Germany
| | - Christian Gross
- Max-Planck-Institut für Quantenoptik, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), 80799 München, Germany
- Physikalisches Institut, Eberhard Karls Universität Tübingen, 72076 Tübingen, Germany
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45
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Liu YJ, Smith A, Knap M, Pollmann F. Model-Independent Learning of Quantum Phases of Matter with Quantum Convolutional Neural Networks. PHYSICAL REVIEW LETTERS 2023; 130:220603. [PMID: 37327416 DOI: 10.1103/physrevlett.130.220603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 05/16/2023] [Indexed: 06/18/2023]
Abstract
Quantum convolutional neural networks (QCNNs) have been introduced as classifiers for gapped quantum phases of matter. Here, we propose a model-independent protocol for training QCNNs to discover order parameters that are unchanged under phase-preserving perturbations. We initiate the training sequence with the fixed-point wave functions of the quantum phase and add translation-invariant noise that respects the symmetries of the system to mask the fixed-point structure on short length scales. We illustrate this approach by training the QCNN on phases protected by time-reversal symmetry in one dimension, and test it on several time-reversal symmetric models exhibiting trivial, symmetry-breaking, and symmetry-protected topological order. The QCNN discovers a set of order parameters that identifies all three phases and accurately predicts the location of the phase boundary. The proposed protocol paves the way toward hardware-efficient training of quantum phase classifiers on a programmable quantum processor.
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Affiliation(s)
- Yu-Jie Liu
- Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, 80799 München, Germany
| | - Adam Smith
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Michael Knap
- Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, 80799 München, Germany
| | - Frank Pollmann
- Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstrasse 4, 80799 München, Germany
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46
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Jin HK, Knolle J, Knap M. Fractionalized Prethermalization in a Driven Quantum Spin Liquid. PHYSICAL REVIEW LETTERS 2023; 130:226701. [PMID: 37327444 DOI: 10.1103/physrevlett.130.226701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 03/02/2023] [Accepted: 05/15/2023] [Indexed: 06/18/2023]
Abstract
Quantum spin liquids subject to a periodic drive can display fascinating nonequilibrium heating behavior because of their emergent fractionalized quasiparticles. Here, we investigate a driven Kitaev honeycomb model and examine the dynamics of emergent Majorana matter and Z_{2} flux excitations. We uncover a distinct two-step heating profile-dubbed fractionalized prethermalization-and a quasistationary state with vastly different temperatures for the matter and the flux sectors. We argue that this peculiar prethermalization behavior is a consequence of fractionalization. Furthermore, we discuss an experimentally feasible protocol for preparing a zero-flux initial state of the Kiteav honeycomb model with a low energy density, which can be used to observe fractionalized prethermalization in quantum information processing platforms.
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Affiliation(s)
- Hui-Ke Jin
- Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany
| | - Johannes Knolle
- Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße. 4, 80799 München, Germany
- Blackett Laboratory, Imperial College London, London SW7 2AZ, United Kingdom
| | - Michael Knap
- Technical University of Munich, TUM School of Natural Sciences, Physics Department, 85748 Garching, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstraße. 4, 80799 München, Germany
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47
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Zhu GY, Chen JY, Ye P, Trebst S. Topological Fracton Quantum Phase Transitions by Tuning Exact Tensor Network States. PHYSICAL REVIEW LETTERS 2023; 130:216704. [PMID: 37295077 DOI: 10.1103/physrevlett.130.216704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2022] [Revised: 03/06/2023] [Accepted: 05/04/2023] [Indexed: 06/12/2023]
Abstract
Gapped fracton phases of matter generalize the concept of topological order and broaden our fundamental understanding of entanglement in quantum many-body systems. However, their analytical or numerical description beyond exactly solvable models remains a formidable challenge. Here we employ an exact 3D quantum tensor-network approach that allows us to study a Z_{N} generalization of the prototypical X cube fracton model and its quantum phase transitions between distinct topological states via fully tractable wave function deformations. We map the (deformed) quantum states exactly to a combination of a classical lattice gauge theory and a plaquette clock model, and employ numerical techniques to calculate various entanglement order parameters. For the Z_{N} model we find a family of (weakly) first-order fracton confinement transitions that in the limit of N→∞ converge to a continuous phase transition beyond the Landau-Ginzburg-Wilson paradigm. We also discover a line of 3D conformal quantum critical points (with critical magnetic flux loop fluctuations) which, in the N→∞ limit, appears to coexist with a gapless deconfined fracton state.
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Affiliation(s)
- Guo-Yi Zhu
- Institute for Theoretical Physics, University of Cologne, Zülpicher Straße 77, 50937 Cologne, Germany
| | - Ji-Yao Chen
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-sen University, Guangzhou, 510275, China
- Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany
| | - Peng Ye
- Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices, School of Physics, Sun Yat-sen University, Guangzhou, 510275, China
- State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-sen University, Guangzhou, 510275, China
| | - Simon Trebst
- Institute for Theoretical Physics, University of Cologne, Zülpicher Straße 77, 50937 Cologne, Germany
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48
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Singh K, Bradley CE, Anand S, Ramesh V, White R, Bernien H. Mid-circuit correction of correlated phase errors using an array of spectator qubits. Science 2023:eade5337. [PMID: 37228222 DOI: 10.1126/science.ade5337] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Accepted: 05/15/2023] [Indexed: 05/27/2023]
Abstract
Scaling up invariably error-prone quantum processors is a formidable challenge. Although quantum error correction ultimately promises fault-tolerant operation, the required qubit overhead and error thresholds are daunting. In a complementary proposal, co-located, auxiliary 'spectator' qubits act as in-situ probes of noise, and enable real-time, coherent corrections of data qubit errors. We use an array of cesium spectator qubits to correct correlated phase errors on an array of rubidium data qubits. By combining in-sequence readout, data processing, and feed-forward operations, these correlated errors are suppressed within the execution of the quantum circuit. The protocol is broadly applicable to quantum information platforms, and establishes key tools for scaling neutral-atom quantum processors: mid-circuit readout of atom arrays, real-time processing and feed-forward, and coherent mid-circuit reloading of atomic qubits.
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Affiliation(s)
- K Singh
- Intelligence Community Postdoctoral Research Fellowship Program, Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - C E Bradley
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - S Anand
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - V Ramesh
- Department of Physics, University of Chicago, Chicago, IL 60637, USA
| | - R White
- Department of Physics, University of Chicago, Chicago, IL 60637, USA
| | - H Bernien
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
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49
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Yan Z, Wang YC, Samajdar R, Sachdev S, Meng ZY. Emergent Glassy Behavior in a Kagome Rydberg Atom Array. PHYSICAL REVIEW LETTERS 2023; 130:206501. [PMID: 37267547 DOI: 10.1103/physrevlett.130.206501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/12/2023] [Accepted: 03/16/2023] [Indexed: 06/04/2023]
Abstract
We present large-scale quantum Monte Carlo simulation results on a realistic Hamiltonian of kagome-lattice Rydberg atom arrays. Although the system has no intrinsic disorder, intriguingly, our analyses of static and dynamic properties on large system sizes reveal emergent glassy behavior in a region of parameter space located between two valence bond solid phases. The extent of this glassy region is demarcated using the Edwards-Anderson order parameter, and its phase transitions to the two proximate valence bond solids-as well as the crossover towards a trivial paramagnetic phase-are identified. We demonstrate the intrinsically slow (imaginary) time dynamics deep inside the glassy phase and discuss experimental considerations for detecting such a quantum disordered phase with numerous nearly degenerate local minima. Our proposal paves a new route to the study of real-time glassy phenomena and highlights the potential for quantum simulation of a distinct phase of quantum matter beyond solids and liquids in current-generation Rydberg platforms.
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Affiliation(s)
- Zheng Yan
- Department of Physics and HKU-UCAS Joint Institute of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
| | - Yan-Cheng Wang
- Beihang Hangzhou Innovation Institute Yuhang, Hangzhou 310023, China
- Zhongfa Aviation Institute of Beihang University, Hangzhou 310023, China
| | - Rhine Samajdar
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
- Princeton Center for Theoretical Science, Princeton University, Princeton, New Jersey 08544, USA
| | - Subir Sachdev
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Zi Yang Meng
- Department of Physics and HKU-UCAS Joint Institute of Theoretical and Computational Physics, The University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
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50
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Shaw AL, Scholl P, Finklestein R, Madjarov IS, Grinkemeyer B, Endres M. Dark-State Enhanced Loading of an Optical Tweezer Array. PHYSICAL REVIEW LETTERS 2023; 130:193402. [PMID: 37243641 DOI: 10.1103/physrevlett.130.193402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 04/25/2023] [Indexed: 05/29/2023]
Abstract
Neutral atoms and molecules trapped in optical tweezers have become a prevalent resource for quantum simulation, computation, and metrology. However, the maximum achievable system sizes of such arrays are often limited by the stochastic nature of loading into optical tweezers, with a typical loading probability of only 50%. Here we present a species-agnostic method for dark-state enhanced loading (DSEL) based on real-time feedback, long-lived shelving states, and iterated array reloading. We demonstrate this technique with a 95-tweezer array of ^{88}Sr atoms, achieving a maximum loading probability of 84.02(4)% and a maximum array size of 91 atoms in one dimension. Our protocol is complementary to, and compatible with, existing schemes for enhanced loading based on direct control over light-assisted collisions, and we predict it can enable close-to-unity filling for arrays of atoms or molecules.
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Affiliation(s)
- Adam L Shaw
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - Pascal Scholl
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - Ran Finklestein
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - Ivaylo S Madjarov
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
| | - Brandon Grinkemeyer
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - Manuel Endres
- Division of Physics, Mathematics and Astronomy, California Institute of Technology, Pasadena, California 91125, USA
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