1
|
Zhou A, Sun Z, Sun L. Stable organic radical qubits and their applications in quantum information science. Innovation (N Y) 2024; 5:100662. [PMID: 39091459 PMCID: PMC11292369 DOI: 10.1016/j.xinn.2024.100662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2024] [Accepted: 06/20/2024] [Indexed: 08/04/2024] Open
Abstract
The past century has witnessed the flourishing of organic radical chemistry. Stable organic radicals are highly valuable for quantum technologies thanks to their inherent room temperature quantum coherence, atomic-level designability, and fine tunability. In this comprehensive review, we highlight the potential of stable organic radicals as high-temperature qubits and explore their applications in quantum information science, which remain largely underexplored. Firstly, we summarize known spin dynamic properties of stable organic radicals and examine factors that influence their electron spin relaxation and decoherence times. This examination reveals their design principles and optimal operating conditions. We further discuss their integration in solid-state materials and surface structures, and present their state-of-the-art applications in quantum computing, quantum memory, and quantum sensing. Finally, we analyze the primary challenges associated with stable organic radical qubits and provide tentative insights to future research directions.
Collapse
Affiliation(s)
- Aimei Zhou
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Zhecheng Sun
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
| | - Lei Sun
- Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, Hangzhou 310030, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou 310024, China
- Key Laboratory for Quantum Materials of Zhejiang Province, Department of Physics, School of Science, Westlake University, Hangzhou 310030, China
| |
Collapse
|
2
|
Quiroz G, Pokharel B, Boen J, Tewala L, Tripathi V, Williams D, Wu LA, Titum P, Schultz K, Lidar D. Dynamically generated decoherence-free subspaces and subsystems on superconducting qubits. REPORTS ON PROGRESS IN PHYSICS. PHYSICAL SOCIETY (GREAT BRITAIN) 2024; 87:097601. [PMID: 39059436 DOI: 10.1088/1361-6633/ad6805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Accepted: 07/15/2024] [Indexed: 07/28/2024]
Abstract
Decoherence-free subspaces and subsystems (DFS) preserve quantum information by encoding it into symmetry-protected states unaffected by decoherence. An inherent DFS of a given experimental system may not exist; however, through the use of dynamical decoupling (DD), one can induce symmetries that support DFSs. Here, we provide the first experimental demonstration of DD-generated decoherence-free subsystem logical qubits. Utilizing IBM Quantum superconducting processors, we investigate two and three-qubit DFS codes comprising up to six and seven noninteracting logical qubits, respectively. Through a combination of DD and error detection, we show that DFS logical qubits can achieve up to a 23% improvement in state preservation fidelity over physical qubits subject to DD alone. This constitutes a beyond-breakeven fidelity improvement for DFS-encoded qubits. Our results showcase the potential utility of DFS codes as a pathway toward enhanced computational accuracy via logical encoding on quantum processors.
Collapse
Affiliation(s)
- Gregory Quiroz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States of America
- William H. Miller III Department of Physics & Astronomy, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Bibek Pokharel
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, United States of America
- Center for Quantum Information Science & Technology, University of Southern California, Los Angeles, CA 90089, United States of America
| | - Joseph Boen
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States of America
| | - Lina Tewala
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States of America
- Thomas C. Jenkins Department of Biophysics, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Vinay Tripathi
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, United States of America
- Center for Quantum Information Science & Technology, University of Southern California, Los Angeles, CA 90089, United States of America
| | - Devon Williams
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States of America
- William H. Miller III Department of Physics & Astronomy, Johns Hopkins University, Baltimore, MD 21218, United States of America
| | - Lian-Ao Wu
- Department of Theoretical Physics and History of Science, University of the Basque Country, Leioa 48008, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48011, Spain
- EHU Quantum Center, University of the Basque Country UPV/EHU, Leioa, Biscay 48940, Spain
| | - Paraj Titum
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States of America
| | - Kevin Schultz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD 20723, United States of America
| | - Daniel Lidar
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, United States of America
- Center for Quantum Information Science & Technology, University of Southern California, Los Angeles, CA 90089, United States of America
- Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, United States of America
- Department of Chemistry, University of Southern California, Los Angeles, CA 90089, United States of America
| |
Collapse
|
3
|
Ji Y, Polian I. Synergistic Dynamical Decoupling and Circuit Design for Enhanced Algorithm Performance on Near-Term Quantum Devices. ENTROPY (BASEL, SWITZERLAND) 2024; 26:586. [PMID: 39056948 PMCID: PMC11276410 DOI: 10.3390/e26070586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Revised: 07/01/2024] [Accepted: 07/08/2024] [Indexed: 07/28/2024]
Abstract
Dynamical decoupling (DD) is a promising technique for mitigating errors in near-term quantum devices. However, its effectiveness depends on both hardware characteristics and algorithm implementation details. This paper explores the synergistic effects of dynamical decoupling and optimized circuit design in maximizing the performance and robustness of algorithms on near-term quantum devices. By utilizing eight IBM quantum devices, we analyze how hardware features and algorithm design impact the effectiveness of DD for error mitigation. Our analysis takes into account factors such as circuit fidelity, scheduling duration, and hardware-native gate set. We also examine the influence of algorithmic implementation details, including specific gate decompositions, DD sequences, and optimization levels. The results reveal an inverse relationship between the effectiveness of DD and the inherent performance of the algorithm. Furthermore, we emphasize the importance of gate directionality and circuit symmetry in improving performance. This study offers valuable insights for optimizing DD protocols and circuit designs, highlighting the significance of a holistic approach that leverages both hardware features and algorithm design for the high-quality and reliable execution of near-term quantum algorithms.
Collapse
Affiliation(s)
- Yanjun Ji
- Institute of Computer Architecture and Computer Engineering, University of Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart, Germany;
| | | |
Collapse
|
4
|
Korzeczek MC, Dagys L, Müller C, Tratzmiller B, Salhov A, Eichhorn T, Scheuer J, Knecht S, Plenio MB, Schwartz I. Towards a unified picture of polarization transfer - pulsed DNP and chemically equivalent PHIP. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 362:107671. [PMID: 38614057 DOI: 10.1016/j.jmr.2024.107671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 03/30/2024] [Accepted: 04/03/2024] [Indexed: 04/15/2024]
Abstract
Nuclear spin hyperpolarization techniques, such as dynamic nuclear polarization (DNP) and parahydrogen-induced polarization (PHIP), have revolutionized nuclear magnetic resonance and magnetic resonance imaging. In these methods, a readily available source of high spin order, either electron spins in DNP or singlet states in hydrogen for PHIP, is brought into close proximity with nuclear spin targets, enabling efficient transfer of spin order under external quantum control. Despite vast disparities in energy scales and interaction mechanisms between electron spins in DNP and nuclear singlet states in PHIP, a pseudo-spin formalism allows us to establish an intriguing equivalence. As a result, the important low-field polarization transfer regime of PHIP can be mapped onto an analogous system equivalent to pulsed-DNP. This establishes a correspondence between key polarization transfer sequences in PHIP and DNP, facilitating the transfer of sequence development concepts. This promises fresh insights and significant cross-pollination between DNP and PHIP polarization sequence developers.
Collapse
Affiliation(s)
- Martin C Korzeczek
- Institute of Theoretical Physics and IQST, Albert-Einstein Allee 11, Ulm University, 89081, Ulm, Germany
| | | | | | - Benedikt Tratzmiller
- Institute of Theoretical Physics and IQST, Albert-Einstein Allee 11, Ulm University, 89081, Ulm, Germany; Carl Zeiss MultiSEM GmbH, 73447, Oberkochen, Germany
| | - Alon Salhov
- NVision Imaging Technologies GmbH, 89081, Ulm, Germany; Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem, 91904, Givat Ram, Israel
| | - Tim Eichhorn
- NVision Imaging Technologies GmbH, 89081, Ulm, Germany
| | | | | | - Martin B Plenio
- Institute of Theoretical Physics and IQST, Albert-Einstein Allee 11, Ulm University, 89081, Ulm, Germany.
| | - Ilai Schwartz
- NVision Imaging Technologies GmbH, 89081, Ulm, Germany.
| |
Collapse
|
5
|
Stasiuk A, Peng P, Heller G, Cappellaro P. Frame change technique for phase transient cancellation. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 362:107688. [PMID: 38678738 DOI: 10.1016/j.jmr.2024.107688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 04/12/2024] [Accepted: 04/14/2024] [Indexed: 05/01/2024]
Abstract
The precise control of complex quantum mechanical systems can unlock applications ranging from quantum simulation to quantum computation. Controlling strongly interacting many-body systems often relies on Floquet Hamiltonian engineering that is achieved by fast switching between Hamiltonian primitives via external control. For example, in our solid-state NMR system, we perform quantum simulation by modulating the natural Hamiltonian with control pulses. As the Floquet heating errors scale with the interpulse delay, δt, it is favorable to keep δt as short as possible, forcing our control pulses to be short duration and high power. Additionally, high-power pulses help to minimize undesirable evolution from occurring during the duration of the pulse. However, such pulses introduce an appreciable phase-transient control error, a form of unitary error. In this work, we detail our ability to diagnose the error, calibrate its magnitude, and correct it for π/2-pulses of arbitrary phase. We demonstrate the improvements gained by correcting for the phase transient error, using a method which we call the "frame-change technique", in a variety of experimental settings of interest. Given that the correction mechanism adds no real control overhead, we recommend that any resonance probe be checked for these phase transient control errors, and correct them using the frame-change technique.
Collapse
Affiliation(s)
- Andrew Stasiuk
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA.
| | - Pai Peng
- Department of Electrical and Computer Engineering, Princeton University, Princeton, 08544, NJ, USA
| | - Garrett Heller
- Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| | - Paola Cappellaro
- Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA; Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA; Department of Physics, Massachusetts Institute of Technology, Cambridge, 02139, MA, USA
| |
Collapse
|
6
|
Jones JA. Controlling NMR spin systems for quantum computation. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2024; 140-141:49-85. [PMID: 38705636 DOI: 10.1016/j.pnmrs.2024.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 05/07/2024]
Abstract
Nuclear magnetic resonance is arguably both the best available quantum technology for implementing simple quantum computing experiments and the worst technology for building large scale quantum computers that has ever been seriously put forward. After a few years of rapid growth, leading to an implementation of Shor's quantum factoring algorithm in a seven-spin system, the field started to reach its natural limits and further progress became challenging. Rather than pursuing more complex algorithms on larger systems, interest has now largely moved into developing techniques for the precise and efficient manipulation of spin states with the aim of developing methods that can be applied in other more scalable technologies and within conventional NMR. However, the user friendliness of NMR implementations means that they remain popular for proof-of-principle demonstrations of simple quantum information protocols.
Collapse
Affiliation(s)
- Jonathan A Jones
- Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| |
Collapse
|
7
|
Senkalla K, Genov G, Metsch MH, Siyushev P, Jelezko F. Germanium Vacancy in Diamond Quantum Memory Exceeding 20 ms. PHYSICAL REVIEW LETTERS 2024; 132:026901. [PMID: 38277597 DOI: 10.1103/physrevlett.132.026901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 11/29/2023] [Indexed: 01/28/2024]
Abstract
Negatively charged group-IV defects in diamond show great potential as quantum network nodes due to their efficient spin-photon interface. However, reaching sufficiently long coherence times remains a challenge. In this work, we demonstrate coherent control of germanium vacancy center (GeV) at millikelvin temperatures and extend its coherence time by several orders of magnitude to more than 20 ms. We model the magnetic and amplitude noise as an Ornstein-Uhlenbeck process, reproducing the experimental results well. The utilized method paves the way to optimized coherence times of group-IV defects in various experimental conditions and their successful applications in quantum technologies.
Collapse
Affiliation(s)
- Katharina Senkalla
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Genko Genov
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Mathias H Metsch
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - Petr Siyushev
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
- 3rd Institute of Physics, Center for Applied Quantum Technologies University of Stuttgart, Stuttgart, Germany
- Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
| | - Fedor Jelezko
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| |
Collapse
|
8
|
Rizzato R, Schalk M, Mohr S, Hermann JC, Leibold JP, Bruckmaier F, Salvitti G, Qian C, Ji P, Astakhov GV, Kentsch U, Helm M, Stier AV, Finley JJ, Bucher DB. Extending the coherence of spin defects in hBN enables advanced qubit control and quantum sensing. Nat Commun 2023; 14:5089. [PMID: 37607945 PMCID: PMC10444786 DOI: 10.1038/s41467-023-40473-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 07/26/2023] [Indexed: 08/24/2023] Open
Abstract
Negatively-charged boron vacancy centers ([Formula: see text]) in hexagonal Boron Nitride (hBN) are attracting increasing interest since they represent optically-addressable qubits in a van der Waals material. In particular, these spin defects have shown promise as sensors for temperature, pressure, and static magnetic fields. However, their short spin coherence time limits their scope for quantum technology. Here, we apply dynamical decoupling techniques to suppress magnetic noise and extend the spin coherence time by two orders of magnitude, approaching the fundamental T1 relaxation limit. Based on this improvement, we demonstrate advanced spin control and a set of quantum sensing protocols to detect radiofrequency signals with sub-Hz resolution. The corresponding sensitivity is benchmarked against that of state-of-the-art NV-diamond quantum sensors. This work lays the foundation for nanoscale sensing using spin defects in an exfoliable material and opens a promising path to quantum sensors and quantum networks integrated into ultra-thin structures.
Collapse
Affiliation(s)
- Roberto Rizzato
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstraße 4, Garching bei München, 85748, Germany.
- University of Bari, Department of Physics "M. Merlin", Via Amendola 173, Bari, 70125, Italy.
| | - Martin Schalk
- Walter Schottky Institute, TUM School of Natural Sciences, Am Coulombwall 4, Garching bei München, 85748, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, München, D-80799, Germany
| | - Stephan Mohr
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstraße 4, Garching bei München, 85748, Germany
| | - Jens C Hermann
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstraße 4, Garching bei München, 85748, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, München, D-80799, Germany
| | - Joachim P Leibold
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstraße 4, Garching bei München, 85748, Germany
- Technical University of Munich, TUM School of Natural Sciences, Department of Physics, James-Franck-Str. 1, Garching bei München, 85748, Germany
| | - Fleming Bruckmaier
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstraße 4, Garching bei München, 85748, Germany
| | - Giovanna Salvitti
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstraße 4, Garching bei München, 85748, Germany
- University of Bologna, Department of Chemistry "G. Ciamician", Via Selmi, 2, Bologna, 40126, Italy
| | - Chenjiang Qian
- Walter Schottky Institute, TUM School of Natural Sciences, Am Coulombwall 4, Garching bei München, 85748, Germany
| | - Peirui Ji
- Walter Schottky Institute, TUM School of Natural Sciences, Am Coulombwall 4, Garching bei München, 85748, Germany
| | - Georgy V Astakhov
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, Dresden, 01328, Germany
| | - Ulrich Kentsch
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, Dresden, 01328, Germany
| | - Manfred Helm
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Ion Beam Physics and Materials Research, Bautzner Landstraße 400, Dresden, 01328, Germany
- TU Dresden, 01062, Dresden, Germany
| | - Andreas V Stier
- Walter Schottky Institute, TUM School of Natural Sciences, Am Coulombwall 4, Garching bei München, 85748, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, München, D-80799, Germany
| | - Jonathan J Finley
- Walter Schottky Institute, TUM School of Natural Sciences, Am Coulombwall 4, Garching bei München, 85748, Germany
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, München, D-80799, Germany
| | - Dominik B Bucher
- Technical University of Munich, TUM School of Natural Sciences, Department of Chemistry, Lichtenbergstraße 4, Garching bei München, 85748, Germany.
- Munich Center for Quantum Science and Technology (MCQST), Schellingstr. 4, München, D-80799, Germany.
| |
Collapse
|
9
|
Zhang J, Hegde SS, Suter D. Fast Quantum State Tomography in the Nitrogen Vacancy Center of Diamond. PHYSICAL REVIEW LETTERS 2023; 130:090801. [PMID: 36930911 DOI: 10.1103/physrevlett.130.090801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/11/2022] [Accepted: 01/20/2023] [Indexed: 06/18/2023]
Abstract
Quantum state tomography is the procedure for reconstructing unknown quantum states from a series of measurements of different observables. Depending on the physical system, different sets of observables have been used for this procedure. In the case of spin qubits, the most common procedure is to measure the transverse magnetization of the system as a function of time. Here, we present a different scheme that relies on time-independent observables and therefore does not require measurements at different evolution times, thereby greatly reducing the overall measurement time. To recover the full density matrix, we use a set of unitary operations that transform the density operator elements into the directly measurable observable. We demonstrate the performance of this scheme in the electron-nuclear spin system of the nitrogen vacancy center in diamond.
Collapse
Affiliation(s)
- Jingfu Zhang
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Swathi S Hegde
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Dieter Suter
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| |
Collapse
|
10
|
NMR Quantum Information Processing: Indian Contributions and Perspectives. J Indian Inst Sci 2023. [DOI: 10.1007/s41745-022-00353-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
|
11
|
Protectability of IBMQ Qubits by Dynamical Decoupling Technique. Symmetry (Basel) 2022. [DOI: 10.3390/sym15010062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
We study the current effectiveness of the dynamical decoupling technique on a publicly accessible IBM quantum computer (IBMQ). This technique, also known as bang-bang decoupling or dynamical symmetrization, consists of applying sequences of pulses for protecting a qubit from decoherence by symmetrizing the qubit–environment interactions. Works in the field have studied sequences with different symmetries and carried out tests on IBMQ devices typically considering single-qubit states. We show that the simplest universal sequences can be interesting for preserving two-qubit states on the IBMQ device. For this, we considered a collection of single-qubit and two-qubit states. The results indicate that a simple dynamical decoupling approach using available IBMQ pulses is not enough for protecting a general single-qubit state without further care. Nevertheless, the technique is beneficial for the Bell states. This encouraged us to study logical qubit encodings such as |0⟩L≡|01⟩,|1⟩L≡|10⟩, where a quantum state has the form |ψab⟩=a|0⟩L+b|1⟩L. Thus, we explored the effectiveness of dynamical decoupling with a large set of two-qubit |ψab⟩ states, where a and b are real amplitudes. With this, we also determined that the |ψab⟩ states most benefiting from this dynamical decoupling approach and slowed down the decay of their survival probability.
Collapse
|
12
|
Janitz E, Herb K, Völker LA, Huxter WS, Degen CL, Abendroth JM. Diamond surface engineering for molecular sensing with nitrogen-vacancy centers. JOURNAL OF MATERIALS CHEMISTRY. C 2022; 10:13533-13569. [PMID: 36324301 PMCID: PMC9521415 DOI: 10.1039/d2tc01258h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 08/06/2022] [Indexed: 05/20/2023]
Abstract
Quantum sensing using optically addressable atomic-scale defects, such as the nitrogen-vacancy (NV) center in diamond, provides new opportunities for sensitive and highly localized characterization of chemical functionality. Notably, near-surface defects facilitate detection of the minute magnetic fields generated by nuclear or electron spins outside of the diamond crystal, such as those in chemisorbed and physisorbed molecules. However, the promise of NV centers is hindered by a severe degradation of critical sensor properties, namely charge stability and spin coherence, near surfaces (< ca. 10 nm deep). Moreover, applications in the chemical sciences require methods for covalent bonding of target molecules to diamond with robust control over density, orientation, and binding configuration. This forward-looking Review provides a survey of the rapidly converging fields of diamond surface science and NV-center physics, highlighting their combined potential for quantum sensing of molecules. We outline the diamond surface properties that are advantageous for NV-sensing applications, and discuss strategies to mitigate deleterious effects while simultaneously providing avenues for chemical attachment. Finally, we present an outlook on emerging applications in which the unprecedented sensitivity and spatial resolution of NV-based sensing could provide unique insight into chemically functionalized surfaces at the single-molecule level.
Collapse
Affiliation(s)
- Erika Janitz
- Department of Physics, ETH Zürich Otto-Stern-Weg 1 8093 Zürich Switzerland
| | - Konstantin Herb
- Department of Physics, ETH Zürich Otto-Stern-Weg 1 8093 Zürich Switzerland
| | - Laura A Völker
- Department of Physics, ETH Zürich Otto-Stern-Weg 1 8093 Zürich Switzerland
| | - William S Huxter
- Department of Physics, ETH Zürich Otto-Stern-Weg 1 8093 Zürich Switzerland
| | - Christian L Degen
- Department of Physics, ETH Zürich Otto-Stern-Weg 1 8093 Zürich Switzerland
| | - John M Abendroth
- Department of Physics, ETH Zürich Otto-Stern-Weg 1 8093 Zürich Switzerland
| |
Collapse
|
13
|
Bluvstein D, Levine H, Semeghini G, Wang TT, Ebadi S, Kalinowski M, Keesling A, Maskara N, Pichler H, Greiner M, Vuletić V, Lukin MD. A quantum processor based on coherent transport of entangled atom arrays. Nature 2022; 604:451-456. [PMID: 35444318 PMCID: PMC9021024 DOI: 10.1038/s41586-022-04592-6] [Citation(s) in RCA: 78] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/28/2022] [Indexed: 11/23/2022]
Abstract
The ability to engineer parallel, programmable operations between desired qubits within a quantum processor is key for building scalable quantum information systems1,2. In most state-of-the-art approaches, qubits interact locally, constrained by the connectivity associated with their fixed spatial layout. Here we demonstrate a quantum processor with dynamic, non-local connectivity, in which entangled qubits are coherently transported in a highly parallel manner across two spatial dimensions, between layers of single- and two-qubit operations. Our approach makes use of neutral atom arrays trapped and transported by optical tweezers; hyperfine states are used for robust quantum information storage, and excitation into Rydberg states is used for entanglement generation3–5. We use this architecture to realize programmable generation of entangled graph states, such as cluster states and a seven-qubit Steane code state6,7. Furthermore, we shuttle entangled ancilla arrays to realize a surface code state with thirteen data and six ancillary qubits8 and a toric code state on a torus with sixteen data and eight ancillary qubits9. Finally, we use this architecture to realize a hybrid analogue–digital evolution2 and use it for measuring entanglement entropy in quantum simulations10–12, experimentally observing non-monotonic entanglement dynamics associated with quantum many-body scars13,14. Realizing a long-standing goal, these results provide a route towards scalable quantum processing and enable applications ranging from simulation to metrology. A quantum processer is realized using arrays of neutral atoms that are transported in a parallel manner by optical tweezers during computations, and used for quantum error correction and simulations.
Collapse
Affiliation(s)
- Dolev Bluvstein
- 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
| | | | - Tout T Wang
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Sepehr Ebadi
- Department of Physics, Harvard University, Cambridge, MA, USA
| | | | - Alexander Keesling
- Department of Physics, Harvard University, Cambridge, MA, USA.,QuEra Computing Inc., Boston, MA, USA
| | - Nishad Maskara
- Department of Physics, Harvard University, Cambridge, MA, USA
| | - Hannes Pichler
- Institute for Theoretical Physics, University of Innsbruck, Innsbruck, Austria.,Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Innsbruck, Austria
| | - 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.
| |
Collapse
|
14
|
Bodenstedt S, Moll D, Glöggler S, Mitchell MW, Tayler MCD. Decoupling of Spin Decoherence Paths near Zero Magnetic Field. J Phys Chem Lett 2022; 13:98-104. [PMID: 34962125 DOI: 10.1021/acs.jpclett.1c03714] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
We demonstrate a method to quantify and manipulate nuclear spin decoherence mechanisms that are active in zero to ultralow magnetic fields. These include (i) nonadiabatic switching of spin quantization axis due to residual background fields and (ii) scalar pathways due to through-bond couplings between 1H and heteronuclear spin species, such as 2H used partially as an isotopic substitute for 1H. Under conditions of free evolution, scalar relaxation due to 2H can significantly limit nuclear spin polarization lifetimes and thus the scope of magnetic resonance procedures near zero field. It is shown that robust trains of pulsed dc magnetic fields that apply π flip angles to one or multiple spin species may switch the effective symmetry of the nuclear spin Hamiltonian, imposing decoupled or coupled dynamic regimes on demand. The method should broaden the spectrum of hyperpolarized biomedical contrast-agent compounds and hyperpolarization procedures that are used near zero field.
Collapse
Affiliation(s)
- Sven Bodenstedt
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| | - Denis Moll
- NMR Signal Enhancement Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration, UMG, 37 075 Göttingen, Germany
| | - Stefan Glöggler
- NMR Signal Enhancement Group, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
- Center for Biostructural Imaging of Neurodegeneration, UMG, 37 075 Göttingen, Germany
| | - Morgan W Mitchell
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
- ICREA - Institució Catalana de Recerca i Estudis Avançats, 08 010 Barcelona, Spain
| | - Michael C D Tayler
- ICFO-Institut de Ciències Fotòniques, The Barcelona Institute of Science and Technology, 08860 Castelldefels (Barcelona), Spain
| |
Collapse
|
15
|
Cerrillo J, Oviedo Casado S, Prior J. Low Field Nano-NMR via Three-Level System Control. PHYSICAL REVIEW LETTERS 2021; 126:220402. [PMID: 34152193 DOI: 10.1103/physrevlett.126.220402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 04/20/2021] [Indexed: 06/13/2023]
Abstract
Conventional control strategies for nitrogen-vacancy centers in quantum sensing are based on a two-level model of their triplet ground state. However, this approach fails in regimes of weak bias magnetic fields or strong microwave pulses, as we demonstrate. To overcome this limitation, we propose a novel control sequence that exploits all three levels by addressing a hidden Raman configuration with microwave pulses tuned to the zero-field transition. We report excellent performance in typical dynamical decoupling sequences, opening up the possibility for nano-NMR operation in low field environments.
Collapse
Affiliation(s)
- J Cerrillo
- Área de Física Aplicada, Universidad Politécnica de Cartagena, Cartagena E-30202, Spain
| | - S Oviedo Casado
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Givat Ram, Israel
| | - J Prior
- Área de Física Aplicada, Universidad Politécnica de Cartagena, Cartagena E-30202, Spain
- Departamento de Física-CIOyN, Universidad de Murcia, Murcia E-30071, Spain
- Instituto Carlos I de Física teórica y Computacional, Universidad de Granada, Granada E-18071, Spain
| |
Collapse
|
16
|
Nizovtsev AP, Pushkarchuk AL, Kilin SY, Kargin NI, Gusev AS, Smirnova MO, Jelezko F. Hyperfine Interactions in the NV- 13C Quantum Registers in Diamond Grown from the Azaadamantane Seed. NANOMATERIALS (BASEL, SWITZERLAND) 2021; 11:1303. [PMID: 34069205 PMCID: PMC8156205 DOI: 10.3390/nano11051303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 05/06/2021] [Accepted: 05/07/2021] [Indexed: 11/17/2022]
Abstract
Nanostructured diamonds hosting optically active paramagnetic color centers (NV, SiV, GeV, etc.) and hyperfine-coupled with them quantum memory 13C nuclear spins situated in diamond lattice are currently of great interest to implement emerging quantum technologies (quantum information processing, quantum sensing and metrology). Current methods of creation such as electronic-nuclear spin systems are inherently probabilistic with respect to mutual location of color center electronic spin and 13C nuclear spins. A new bottom-up approach to fabricate such systems is to synthesize first chemically appropriate diamond-like organic molecules containing desired isotopic constituents in definite positions and then use them as a seed for diamond growth to produce macroscopic diamonds, subsequently creating vacancy-related color centers in them. In particular, diamonds incorporating coupled NV-13C spin systems (quantum registers) with specific mutual arrangements of NV and 13C can be obtained from anisotopic azaadamantane molecule. Here we predict the characteristics of hyperfine interactions (hfi) for the NV-13C systems in diamonds grown from various isotopically substituted azaadamantane molecules differing in 13C position in the seed, as well as the orientation of the NV center in the post-obtained diamond. We used the spatial and hfi data simulated earlier for the H-terminated cluster C510[NV]-H252. The data obtained can be used to identify (and correlate with the seed used) the specific NV-13C spin system by measuring, e.g., the hfi-induced splitting of the mS = ±1 sublevels of the NV center in optically detected magnetic resonance (ODMR) spectra being characteristic for various NV-13C systems.
Collapse
Affiliation(s)
- Alexander P. Nizovtsev
- National Research Nuclear University “MEPhI”, 115409 Moscow, Russia; (A.L.P.); (N.I.K.); (A.S.G.); (M.O.S.)
| | - Aliaksandr L. Pushkarchuk
- National Research Nuclear University “MEPhI”, 115409 Moscow, Russia; (A.L.P.); (N.I.K.); (A.S.G.); (M.O.S.)
| | - Sergei Ya. Kilin
- Institute of Physics, Nat. Acad. Sci. of Belarus, 220072 Minsk, Belarus;
| | - Nikolai I. Kargin
- National Research Nuclear University “MEPhI”, 115409 Moscow, Russia; (A.L.P.); (N.I.K.); (A.S.G.); (M.O.S.)
| | - Alexander S. Gusev
- National Research Nuclear University “MEPhI”, 115409 Moscow, Russia; (A.L.P.); (N.I.K.); (A.S.G.); (M.O.S.)
| | - Marina O. Smirnova
- National Research Nuclear University “MEPhI”, 115409 Moscow, Russia; (A.L.P.); (N.I.K.); (A.S.G.); (M.O.S.)
| | - Fedor Jelezko
- Institute for Quantum Optics, Ulm University, 89069 Ulm, Germany;
| |
Collapse
|
17
|
Abah O, Puebla R, Paternostro M. Quantum State Engineering by Shortcuts to Adiabaticity in Interacting Spin-Boson Systems. PHYSICAL REVIEW LETTERS 2020; 124:180401. [PMID: 32441978 DOI: 10.1103/physrevlett.124.180401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/20/2020] [Indexed: 06/11/2023]
Abstract
We present a fast and robust framework to prepare nonclassical states of a bosonic mode exploiting a coherent exchange of excitations with a two-level system ruled by a Jaynes-Cummings interaction mechanism. Our protocol, which is built on shortcuts to adiabaticity, allows for the generation of arbitrary Fock states of the bosonic mode, as well as coherent quantum superpositions of a Schrödinger cat-like form. In addition, we show how to obtain a class of photon-shifted states where the vacuum population is removed, a result akin to photon addition, but displaying more nonclassicality than standard photon-added states. Owing to the ubiquity of the spin-boson interaction that we consider, our proposal is amenable for implementations in state-of-the-art experiments.
Collapse
Affiliation(s)
- Obinna Abah
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Ricardo Puebla
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Mauro Paternostro
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| |
Collapse
|
18
|
Enhancing the Robustness of Dynamical Decoupling Sequences with Correlated Random Phases. Symmetry (Basel) 2020. [DOI: 10.3390/sym12050730] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We show that the addition of correlated phases to the recently developed method of randomized dynamical decoupling pulse sequences can improve its performance in quantum sensing. In particular, by correlating the relative phases of basic pulse units in dynamical decoupling sequences, we are able to improve the suppression of the signal distortion due to π pulse imperfections and spurious responses due to finite-width π pulses. This enhances the selectivity of quantum sensors such as those based on NV centers in diamond.
Collapse
|
19
|
Unden TK, Louzon D, Zwolak M, Zurek WH, Jelezko F. Revealing the Emergence of Classicality Using Nitrogen-Vacancy Centers. PHYSICAL REVIEW LETTERS 2019; 123:140402. [PMID: 31702205 PMCID: PMC7003699 DOI: 10.1103/physrevlett.123.140402] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 08/08/2019] [Indexed: 06/10/2023]
Abstract
The origin of classical reality in our quantum world is a long-standing mystery. Here, we examine a nitrogen-vacancy center in diamond evolving in the presence of its magnetic nuclear spin environment which is formed by the natural appearance of carbon ^{13}C atoms in the diamond lattice, to study quantum Darwinism-the proliferation of information about preferred quantum states throughout the world via the environment. This redundantly imprinted information accounts for the perception of objective reality, as it is independently accessible by many without perturbing the system of interest. To observe this process, we implement a novel dynamical decoupling scheme that enables the measurement and control of several nuclear spins (the environment E) interacting with a nitrogen vacancy (the system S). Our experiment demonstrates that, in the course of the decoherence of S, redundant information is indeed imprinted onto E, giving rise to incipient classical objectivity-a consensus recorded in redundant copies, and available from the fragments of the nuclear spin environment E, about the state of S. This provides the first laboratory verification of the process responsible for the emergence of the objective classical world from the underlying quantum substrate.
Collapse
Affiliation(s)
- T K Unden
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
| | - D Louzon
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
- Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - M Zwolak
- Biophysics Group, Microsystems and Nanotechnology Division, Physical Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - W H Zurek
- Theory Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - F Jelezko
- Institute for Quantum Optics, Ulm University, Albert-Einstein-Allee 11, Ulm 89081, Germany
- Center for Integrated Quantum Science and Technology (IQst), Ulm University, Ulm 89081 Germany
| |
Collapse
|
20
|
Wang ZY, Lang JE, Schmitt S, Lang J, Casanova J, McGuinness L, Monteiro TS, Jelezko F, Plenio MB. Randomization of Pulse Phases for Unambiguous and Robust Quantum Sensing. PHYSICAL REVIEW LETTERS 2019; 122:200403. [PMID: 31172750 DOI: 10.1103/physrevlett.122.200403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Indexed: 06/09/2023]
Abstract
We develop theoretically and demonstrate experimentally a universal dynamical decoupling method for robust quantum sensing with unambiguous signal identification. Our method uses randomization of control pulses to simultaneously suppress two types of errors in the measured spectra that would otherwise lead to false signal identification. These are spurious responses due to finite-width π pulses, as well as signal distortion caused by π pulse imperfections. For the cases of nanoscale nuclear-spin sensing and ac magnetometry, we benchmark the performance of the protocol with a single nitrogen vacancy center in diamond against widely used nonrandomized pulse sequences. Our method is general and can be combined with existing multipulse quantum sensing sequences to enhance their performance.
Collapse
Affiliation(s)
- Zhen-Yu Wang
- Institut für Theoretische Physik und IQST, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - Jacob E Lang
- Department of Physics and Astronomy, University College London, Gower Street, London, England WC1E 6BT, United Kingdom
| | - Simon Schmitt
- Institute of Quantum Optics, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - Johannes Lang
- Institute of Quantum Optics, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - Jorge Casanova
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080 Bilbao, Spain
- Ikerbasque, Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain
| | - Liam McGuinness
- Institute of Quantum Optics, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - Tania S Monteiro
- Department of Physics and Astronomy, University College London, Gower Street, London, England WC1E 6BT, United Kingdom
| | - Fedor Jelezko
- Institute of Quantum Optics, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| | - Martin B Plenio
- Institut für Theoretische Physik und IQST, Universität Ulm, Albert-Einstein-Allee 11, D-89069 Ulm, Germany
| |
Collapse
|
21
|
Casanova J, Torrontegui E, Plenio MB, García-Ripoll JJ, Solano E. Modulated Continuous Wave Control for Energy-Efficient Electron-Nuclear Spin Coupling. PHYSICAL REVIEW LETTERS 2019; 122:010407. [PMID: 31012690 DOI: 10.1103/physrevlett.122.010407] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Indexed: 06/09/2023]
Abstract
We develop energy efficient, continuous microwave schemes to couple electron and nuclear spins, using phase or amplitude modulation to bridge their frequency difference. These controls have promising applications in biological systems, where microwave power should be limited, as well as in situations with high Larmor frequencies due to large magnetic fields and nuclear magnetic moments. These include nanoscale NMR where high magnetic fields achieves enhanced thermal nuclear polarization and larger chemical shifts. Our controls are also suitable for quantum information processors and nuclear polarization schemes.
Collapse
Affiliation(s)
- J Casanova
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080 Bilbao, Spain
- IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain
| | - E Torrontegui
- Instituto de Física Fundamental IFF-CSIC, Calle Serrano 113b, 28006 Madrid, Spain
| | - M B Plenio
- Institut für Theoretische Physik and IQST, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm, Germany
| | - J J García-Ripoll
- Instituto de Física Fundamental IFF-CSIC, Calle Serrano 113b, 28006 Madrid, Spain
| | - E Solano
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080 Bilbao, Spain
- IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013 Bilbao, Spain
- Department of Physics, Shanghai University, 200444 Shanghai, China
| |
Collapse
|
22
|
Masuyama Y, Mizuno K, Ozawa H, Ishiwata H, Hatano Y, Ohshima T, Iwasaki T, Hatano M. Extending coherence time of macro-scale diamond magnetometer by dynamical decoupling with coplanar waveguide resonator. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2018; 89:125007. [PMID: 30599584 DOI: 10.1063/1.5047078] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 11/15/2018] [Indexed: 06/09/2023]
Abstract
Ultimate sensitivity for quantum magnetometry using nitrogen-vacancy (NV) centers in a diamond is limited by a number of NV centers and coherence time. Microwave irradiation with a high and homogeneous power density for a large detection volume is necessary to achieve a highly sensitive magnetometer. Here, we demonstrate a microwave resonator to enhance the power density of the microwave field and an optical system with a detection volume of 1.4 × 10-3 mm3. The strong microwave field enables us to achieve 48 ns Rabi oscillation which is sufficiently faster than the phase relaxation time of NV centers. This system combined with a decoupling pulse sequence, XY16, extends the spin coherence time (T 2) up to 27 times longer than that with a spin echo method. Consequently, we obtained an AC magnetic field sensitivity of 10.8 pt/ Hz using the dynamical decoupling pulse sequence.
Collapse
Affiliation(s)
- Y Masuyama
- Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - K Mizuno
- Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - H Ozawa
- Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - H Ishiwata
- Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - Y Hatano
- Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 5650871, Japan
| | - T Ohshima
- Takasaki Advanced Radiation Research Institute, National Institutes for Quantum and Radiological Science and Technology, Takasaki, Gunma 370-1292, Japan
| | - T Iwasaki
- Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| | - M Hatano
- Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
| |
Collapse
|
23
|
Pokharel B, Anand N, Fortman B, Lidar DA. Demonstration of Fidelity Improvement Using Dynamical Decoupling with Superconducting Qubits. PHYSICAL REVIEW LETTERS 2018; 121:220502. [PMID: 30547654 DOI: 10.1103/physrevlett.121.220502] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Indexed: 06/09/2023]
Abstract
Quantum computers must be able to function in the presence of decoherence. The simplest strategy for decoherence reduction is dynamical decoupling (DD), which requires no encoding overhead and works by converting quantum gates into decoupling pulses. Here, using the IBM and Rigetti platforms, we demonstrate that the DD method is suitable for implementation in today's relatively noisy and small-scale cloud-based quantum computers. Using DD, we achieve substantial fidelity gains relative to unprotected, free evolution of individual superconducting transmon qubits. To a lesser degree, DD is also capable of protecting entangled two-qubit states. We show that dephasing and spontaneous emission errors are dominant in these systems, and that different DD sequences are capable of mitigating both effects. Unlike previous work demonstrating the use of quantum error correcting codes on the same platforms, we make no use of postselection and hence report unconditional fidelity improvements against natural decoherence.
Collapse
Affiliation(s)
- Bibek Pokharel
- Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA
| | - Namit Anand
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
| | - Benjamin Fortman
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
| | - Daniel A Lidar
- Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA
- Department of Physics and Astronomy, University of Southern California, Los Angeles, California 90089, USA
- Department of Chemistry, University of Southern California, Los Angeles, California 90089, USA
- Center for Quantum Information Science & Technology, University of Southern California, Los Angeles, California 90089, USA
| |
Collapse
|
24
|
Haase JF, Wang ZY, Casanova J, Plenio MB. Soft Quantum Control for Highly Selective Interactions among Joint Quantum Systems. PHYSICAL REVIEW LETTERS 2018; 121:050402. [PMID: 30118315 DOI: 10.1103/physrevlett.121.050402] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Indexed: 06/08/2023]
Abstract
We propose a quantum control scheme aimed at interacting systems that gives rise to highly selective coupling among their near-to-resonance constituents. Our protocol implements temporal control of the interaction strength, switching it on and off again adiabatically. This soft temporal modulation significantly suppresses off-resonant contributions in the interactions. Among the applications of our method we show that it allows us to perform an efficient rotating-wave approximation in a wide parameter regime, the elimination of side peaks in quantum sensing experiments, and selective high-fidelity entanglement gates on nuclear spins with close frequencies. We apply our theory to nitrogen-vacancy centers in diamond and demonstrate the possibility for the detection of weak electron-nuclear coupling under the presence of strong perturbations.
Collapse
Affiliation(s)
- J F Haase
- Institut für Theoretische Physik und IQST, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm, Germany
| | - Z-Y Wang
- Institut für Theoretische Physik und IQST, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm, Germany
| | - J Casanova
- Institut für Theoretische Physik und IQST, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm, Germany
| | - M B Plenio
- Institut für Theoretische Physik und IQST, Albert-Einstein-Allee 11, Universität Ulm, D-89069 Ulm, Germany
| |
Collapse
|
25
|
Soetbeer J, Hülsmann M, Godt A, Polyhach Y, Jeschke G. Dynamical decoupling of nitroxides in o-terphenyl: a study of temperature, deuteration and concentration effects. Phys Chem Chem Phys 2018; 20:1615-1628. [DOI: 10.1039/c7cp07074h] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Distinct matrix- and molecule dependencies govern nitroxide decoherence in o-terphenyl at low temperatures, disclosing an optimal range for dynamical decoupling.
Collapse
Affiliation(s)
- Janne Soetbeer
- Laboratory of Physical Chemistry
- ETH Zürich
- CH-8093 Zürich
- Switzerland
| | - Miriam Hülsmann
- Bielefeld University
- Department of Chemistry
- D-33615 Bielefeld
- Germany
| | - Adelheid Godt
- Bielefeld University
- Department of Chemistry
- D-33615 Bielefeld
- Germany
| | - Yevhen Polyhach
- Laboratory of Physical Chemistry
- ETH Zürich
- CH-8093 Zürich
- Switzerland
| | - Gunnar Jeschke
- Laboratory of Physical Chemistry
- ETH Zürich
- CH-8093 Zürich
- Switzerland
| |
Collapse
|
26
|
Genov GT, Schraft D, Vitanov NV, Halfmann T. Arbitrarily Accurate Pulse Sequences for Robust Dynamical Decoupling. PHYSICAL REVIEW LETTERS 2017; 118:133202. [PMID: 28409941 DOI: 10.1103/physrevlett.118.133202] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Indexed: 06/07/2023]
Abstract
We introduce universally robust sequences for dynamical decoupling, which simultaneously compensate pulse imperfections and the detrimental effect of a dephasing environment to an arbitrary order, work with any pulse shape, and improve performance for any initial condition. Moreover, the number of pulses in a sequence grows only linearly with the order of error compensation. Our sequences outperform the state-of-the-art robust sequences for dynamical decoupling. Beyond the theoretical proposal, we also present convincing experimental data for dynamical decoupling of atomic coherences in a solid-state optical memory.
Collapse
Affiliation(s)
- Genko T Genov
- Institut für Angewandte Physik, Technische Universität Darmstadt, Hochschulstr. 6, 64289 Darmstadt, Germany
| | - Daniel Schraft
- Institut für Angewandte Physik, Technische Universität Darmstadt, Hochschulstr. 6, 64289 Darmstadt, Germany
| | - Nikolay V Vitanov
- Department of Physics, St. Kliment Ohridski University of Sofia, 5 James Bourchier blvd, 1164 Sofia, Bulgaria
| | - Thomas Halfmann
- Institut für Angewandte Physik, Technische Universität Darmstadt, Hochschulstr. 6, 64289 Darmstadt, Germany
| |
Collapse
|
27
|
Delayed entanglement echo for individual control of a large number of nuclear spins. Nat Commun 2017; 8:14660. [PMID: 28256508 PMCID: PMC5338027 DOI: 10.1038/ncomms14660] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Accepted: 01/20/2017] [Indexed: 11/29/2022] Open
Abstract
Methods to selectively detect and manipulate nuclear spins by single electrons of solid-state defects play a central role for quantum information processing and nanoscale nuclear magnetic resonance (NMR). However, with standard techniques, no more than eight nuclear spins have been resolved by a single defect centre. Here we develop a method that improves significantly the ability to detect, address and manipulate nuclear spins unambiguously and individually in a broad frequency band by using a nitrogen-vacancy (NV) centre as model system. On the basis of delayed entanglement control, a technique combining microwave and radio frequency fields, our method allows to selectively perform robust high-fidelity entangling gates between hardly resolved nuclear spins and the NV electron. Long-lived qubit memories can be naturally incorporated to our method for improved performance. The application of our ideas will increase the number of useful register qubits accessible to a defect centre and improve the signal of nanoscale NMR. Single electrons of solid-state defects can be used to detect nearby nuclear spins, but so far only a few at a time have been resolved. Here the authors propose an approach based on delayed entanglement echo that demonstrates improved detection and manipulation capabilities of nuclear spins by an NV centre.
Collapse
|
28
|
Koch CP. Controlling open quantum systems: tools, achievements, and limitations. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:213001. [PMID: 27143501 DOI: 10.1088/0953-8984/28/21/213001] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The advent of quantum devices, which exploit the two essential elements of quantum physics, coherence and entanglement, has sparked renewed interest in the control of open quantum systems. Successful implementations face the challenge of preserving relevant nonclassical features at the level of device operation. A major obstacle is decoherence, which is caused by interaction with the environment. Optimal control theory is a tool that can be used to identify control strategies in the presence of decoherence. Here we review recent advances in optimal control methodology that allow typical tasks in device operation for open quantum systems to be tackled and discuss examples of relaxation-optimized dynamics. Optimal control theory is also a useful tool to exploit the environment for control. We discuss examples and point out possible future extensions.
Collapse
Affiliation(s)
- Christiane P Koch
- Theoretische Physik, Universität Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| |
Collapse
|
29
|
Zhang J, Suter D. Experimental protection of two-qubit quantum gates against environmental noise by dynamical decoupling. PHYSICAL REVIEW LETTERS 2015; 115:110502. [PMID: 26406814 DOI: 10.1103/physrevlett.115.110502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Indexed: 06/05/2023]
Abstract
Hybrid systems consisting of different types of qubits are promising for building quantum computers if they combine useful properties of their constituent qubits. However, they also pose additional challenges if one type of qubits is more susceptible to environmental noise than the others. Dynamical decoupling can help to protect such systems by reducing the decoherence due to the environmental noise, but the protection must be designed such that it does not interfere with the control fields driving the logical operations. Here, we test such a protection scheme on a quantum register consisting of the electronic and nuclear spins of a nitrogen-vacancy center in diamond. The results show that processing is compatible with protection: The dephasing time was extended almost to the limit given by the longitudinal relaxation time of the electron spin.
Collapse
Affiliation(s)
- Jingfu Zhang
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Dieter Suter
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| |
Collapse
|
30
|
Rare Earth-Doped Crystals for Quantum Information Processing. HANDBOOK ON THE PHYSICS AND CHEMISTRY OF RARE EARTHS 2015. [DOI: 10.1016/b978-0-444-63260-9.00267-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
|
31
|
Hou SY, Sheng YB, Feng GR, Long GL. Experimental optimal single qubit purification in an NMR quantum information processor. Sci Rep 2014; 4:6857. [PMID: 25358758 PMCID: PMC4215327 DOI: 10.1038/srep06857] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 10/13/2014] [Indexed: 11/09/2022] Open
Abstract
High quality single qubits are the building blocks in quantum information processing. But they are vulnerable to environmental noise. To overcome noise, purification techniques, which generate qubits with higher purities from qubits with lower purities, have been proposed. Purifications have attracted much interest and been widely studied. However, the full experimental demonstration of an optimal single qubit purification protocol proposed by Cirac, Ekert and Macchiavello [Phys. Rev. Lett. 82, 4344 (1999), the CEM protocol] more than one and half decades ago, still remains an experimental challenge, as it requires more complicated networks and a higher level of precision controls. In this work, we design an experiment scheme that realizes the CEM protocol with explicit symmetrization of the wave functions. The purification scheme was successfully implemented in a nuclear magnetic resonance quantum information processor. The experiment fully demonstrated the purification protocol, and showed that it is an effective way of protecting qubits against errors and decoherence.
Collapse
Affiliation(s)
- Shi-Yao Hou
- State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- The Innovative Center of Quantum Matter, Beijing 100084, China
- Tsinghua National Laboratory of Information Science and Technology, Beijing 100084, China
| | - Yu-Bo Sheng
- State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- Institute of Signal Processing Transmission, Nanjing University of Posts and Telecommunications, Nanjing, 210003, China
| | - Guan-Ru Feng
- State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- The Innovative Center of Quantum Matter, Beijing 100084, China
- Tsinghua National Laboratory of Information Science and Technology, Beijing 100084, China
| | - Gui-Lu Long
- State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, Beijing 100084, China
- The Innovative Center of Quantum Matter, Beijing 100084, China
- Tsinghua National Laboratory of Information Science and Technology, Beijing 100084, China
| |
Collapse
|
32
|
Stanek D, Fauseweh B, Stihl C, Pasini S, Uhrig GS. Anomalous behavior of control pulses in presence of noise with singular autocorrelation. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2014; 245:133-142. [PMID: 25036295 DOI: 10.1016/j.jmr.2014.06.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2014] [Revised: 06/05/2014] [Accepted: 06/09/2014] [Indexed: 06/03/2023]
Abstract
We report on the anomalous behavior of control pulses for spins under spin-spin relaxation and subject to classical noise with a singular autocorrelation function. This behavior is not detected for noise with analytic autocorrelation functions. The effect is manifest in the different scaling behavior of the deviation of a real pulse to the ideal, instantaneous one. While a standard pulse displays scaling ∝τp(1), a first-order refocusing pulse normally shows scaling ∝τp(2). But in presence of cusps in the noise autocorrelation the scaling ∝τp(3/2) occurs. Cusps in the autocorrelation are characteristic for fast fluctuations in the noise with a spectral density of Lorentzian shape. We prove that the anomalous exponent cannot be avoided; it represents a fundamental limit. On the one hand, this redefines the strategies one has to adopt to design refocusing pulses. On the other hand, the anomalous exponent, if found in experiment, provides important information on the noise properties.
Collapse
Affiliation(s)
- Daniel Stanek
- Lehrstuhl für Theoretische Physik I, TU Dortmund, Otto-Hahn Straße 4, 44221 Dortmund, Germany
| | - Benedikt Fauseweh
- Lehrstuhl für Theoretische Physik I, TU Dortmund, Otto-Hahn Straße 4, 44221 Dortmund, Germany.
| | - Christopher Stihl
- Institut für Angewandte Materialien - IAM-AWP, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Stefano Pasini
- Jülich Centre for Neutron Science, JCNS, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany.
| | - Götz S Uhrig
- Lehrstuhl für Theoretische Physik I, TU Dortmund, Otto-Hahn Straße 4, 44221 Dortmund, Germany.
| |
Collapse
|
33
|
Zhang J, Souza AM, Brandao FD, Suter D. Protected quantum computing: interleaving gate operations with dynamical decoupling sequences. PHYSICAL REVIEW LETTERS 2014; 112:050502. [PMID: 24580577 DOI: 10.1103/physrevlett.112.050502] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Indexed: 06/03/2023]
Abstract
Implementing precise operations on quantum systems is one of the biggest challenges for building quantum devices in a noisy environment. Dynamical decoupling attenuates the destructive effect of the environmental noise, but so far, it has been used primarily in the context of quantum memories. Here, we experimentally demonstrate a general scheme for combining dynamical decoupling with quantum logical gate operations using the example of an electron-spin qubit of a single nitrogen-vacancy center in diamond. We achieve process fidelities >98% for gate times that are 2 orders of magnitude longer than the unprotected dephasing time T2.
Collapse
Affiliation(s)
- Jingfu Zhang
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| | - Alexandre M Souza
- Centro Brasileiro de Pesquisas Físicas, Rua Dr. Xavier Sigaud 150, Rio de Janeiro 22290-180, RJ, Brazil
| | | | - Dieter Suter
- Fakultät Physik, Technische Universität Dortmund, D-44221 Dortmund, Germany
| |
Collapse
|
34
|
Lovrić M, Suter D, Ferrier A, Goldner P. Faithful solid state optical memory with dynamically decoupled spin wave storage. PHYSICAL REVIEW LETTERS 2013; 111:020503. [PMID: 23889376 DOI: 10.1103/physrevlett.111.020503] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2013] [Indexed: 06/02/2023]
Abstract
We report a high fidelity optical memory in which dynamical decoupling is used to extend the storage time. This is demonstrated in a rare-earth doped crystal in which optical coherences were transferred to nuclear spin coherences and then protected against environmental noise by dynamical decoupling, leading to storage times of up to 4.2 ms. An interference experiment shows that relative phases of input pulses are preserved through the whole storage and retrieval process with a visibility ≈1, demonstrating the usefulness of dynamical decoupling for extending the storage time of quantum memories. We also show that dynamical decoupling sequences insensitive to initial spin coherence increase retrieval efficiency.
Collapse
Affiliation(s)
- Marko Lovrić
- Technische Universität Dortmund, Fakultät Physik, D-44221 Dortmund, Germany
| | | | | | | |
Collapse
|
35
|
Husain S, Kawamura M, Jones JA. Further analysis of some symmetric and antisymmetric composite pulses for tackling pulse strength errors. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 230:145-154. [PMID: 23500528 DOI: 10.1016/j.jmr.2013.02.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 01/30/2013] [Accepted: 02/03/2013] [Indexed: 06/01/2023]
Abstract
Composite pulses have found widespread use in both conventional Nuclear Magnetic Resonance experiments and in experimental quantum information processing to reduce the effects of systematic errors. Here we describe several families of time symmetric and antisymmetric fully compensating composite pulses, inspired by the previous Fn, Gn and BB1 families family developed by Wimperis. We describe families of composite 180° pulses (not gates) which exhibit unprecedented tolerance of pulse strength errors without unreasonable sensitivity to off-resonance errors, and related families with more exotic tailored responses. Next we address the problem of extending these methods to other rotation angles, and discuss numerical results for 90° pulses. Finally we demonstrate the performance of some 90° and 180° pulses in NMR experiments.
Collapse
Affiliation(s)
- Sami Husain
- Centre for Quantum Computation, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | | | | |
Collapse
|
36
|
Serra RM, Oliveira IS. Nuclear magnetic resonance quantum information processing. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:4615-4619. [PMID: 22946031 PMCID: PMC3441066 DOI: 10.1098/rsta.2012.0332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
For the past decade, nuclear magnetic resonance (NMR) has been established as a main experimental technique for testing quantum protocols in small systems. This Theme Issue presents recent advances and major challenges of NMR quantum information possessing (QIP), including contributions by researchers from 10 different countries. In this introduction, after a short comment on NMR-QIP basics, we briefly anticipate the contents of this issue.
Collapse
Affiliation(s)
- R M Serra
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, R. Santa Adélia 166, 09210-170 Santo André, São Paulo, Brazil.
| | | |
Collapse
|