151
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Jamonneau P, Hétet G, Dréau A, Roch JF, Jacques V. Coherent Population Trapping of a Single Nuclear Spin Under Ambient Conditions. PHYSICAL REVIEW LETTERS 2016; 116:043603. [PMID: 26871331 DOI: 10.1103/physrevlett.116.043603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Indexed: 06/05/2023]
Abstract
We demonstrate coherent population trapping of a single nuclear spin in a room-temperature solid. To this end, we exploit a three-level system with a Λ configuration in the microwave domain, which consists of nuclear spin states addressed through their hyperfine coupling to the electron spin of a single nitrogen-vacancy defect in diamond. Moreover, the Λ-scheme relaxation is externally controlled through incoherent optical pumping and separated in time from consecutive coherent microwave excitations. Such a scheme allows us (i) to monitor the sequential accumulation of population into the dark state and (ii) to reach a novel regime of coherent population trapping dynamics for which periodic arrays of dark resonances can be observed, owing to multiple constructive interferences. This Letter offers new prospects for quantum state preparation, information storage in hybrid quantum systems, and metrology.
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Affiliation(s)
- P Jamonneau
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay91405 Orsay Cedex, France
| | - G Hétet
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay91405 Orsay Cedex, France
- Laboratoire Pierre Aigrain, CNRS, Université Pierre et Marie Curie, Université Paris Diderot and Ecole Normale Supérieure, 75005 Paris, France
| | - A Dréau
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay91405 Orsay Cedex, France
| | - J-F Roch
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay91405 Orsay Cedex, France
| | - V Jacques
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud, ENS Cachan, Université Paris-Saclay91405 Orsay Cedex, France
- Laboratoire Charles Coulomb, Université de Montpellier and CNRS, 34095 Montpellier, France
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152
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Fernandez A, Ferrando-Soria J, Pineda EM, Tuna F, Vitorica-Yrezabal IJ, Knappke C, Ujma J, Muryn CA, Timco GA, Barran PE, Ardavan A, Winpenny RE. Making hybrid [n]-rotaxanes as supramolecular arrays of molecular electron spin qubits. Nat Commun 2016; 7:10240. [PMID: 26742716 PMCID: PMC4729860 DOI: 10.1038/ncomms10240] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Accepted: 11/17/2015] [Indexed: 02/04/2023] Open
Abstract
Quantum information processing (QIP) would require that the individual units involved--qubits--communicate to other qubits while retaining their identity. In many ways this resembles the way supramolecular chemistry brings together individual molecules into interlocked structures, where the assembly has one identity but where the individual components are still recognizable. Here a fully modular supramolecular strategy has been to link hybrid organic-inorganic [2]- and [3]-rotaxanes into still larger [4]-, [5]- and [7]-rotaxanes. The ring components are heterometallic octanuclear [Cr7NiF8(O2C(t)Bu)16](-) coordination cages and the thread components template the formation of the ring about the organic axle, and are further functionalized to act as a ligand, which leads to large supramolecular arrays of these heterometallic rings. As the rings have been proposed as qubits for QIP, the strategy provides a possible route towards scalable molecular electron spin devices for QIP. Double electron-electron resonance experiments demonstrate inter-qubit interactions suitable for mediating two-qubit quantum logic gates.
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Affiliation(s)
- Antonio Fernandez
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Jesus Ferrando-Soria
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Eufemio Moreno Pineda
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Floriana Tuna
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Iñigo J. Vitorica-Yrezabal
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | | | - Jakub Ujma
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
- The Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Christopher A. Muryn
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Grigore A. Timco
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Perdita E. Barran
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
- The Michael Barber Centre for Collaborative Mass Spectrometry, Manchester Institute of Biotechnology, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
| | - Arzhang Ardavan
- Department of Physics, Centre for Advanced Electron Spin Resonance, The Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU, UK
| | - Richard E.P. Winpenny
- School of Chemistry and Photon Science Institute, The University of Manchester, Oxford Road, Manchester M13 9PL, UK
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153
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Quantum Zeno and Zeno-like effects in nitrogen vacancy centers. Sci Rep 2015; 5:17615. [PMID: 26620670 PMCID: PMC4664959 DOI: 10.1038/srep17615] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 11/03/2015] [Indexed: 01/16/2023] Open
Abstract
We present a proposal to realize the quantum Zeno effect (QZE) and quantum Zeno-like effect (QZLE) in a proximal (13)C nuclear spin by controlling a proximal electron spin of a nitrogen vacancy (NV) center. The measurement is performed by applying a microwave pulse to induce the transition between different electronic spin states. Under the practical experimental conditions, our calculations show that there exist both QZE and QZLE in a (13)C nuclear spin in the vicinity of an NV center.
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154
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Feng Y, Wang T, Li Y, Li J, Wu J, Wu B, Jiang L, Wang C. Steering Metallofullerene Electron Spin in Porous Metal–Organic Framework. J Am Chem Soc 2015; 137:15055-60. [DOI: 10.1021/jacs.5b10796] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Yongqiang Feng
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Molecular Nanostructure
and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Taishan Wang
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Molecular Nanostructure
and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Yongjian Li
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Molecular Nanostructure
and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jie Li
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Molecular Nanostructure
and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Jingyi Wu
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Molecular Nanostructure
and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Bo Wu
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Molecular Nanostructure
and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Li Jiang
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Molecular Nanostructure
and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
| | - Chunru Wang
- Beijing National Laboratory
for Molecular Sciences, Key Laboratory of Molecular Nanostructure
and Nanotechnology, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China
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155
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Wang P, Liu B, Yang W. Strongly polarizing weakly coupled (13)C nuclear spins with optically pumped nitrogen-vacancy center. Sci Rep 2015; 5:15847. [PMID: 26521962 PMCID: PMC4629148 DOI: 10.1038/srep15847] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Accepted: 10/01/2015] [Indexed: 11/16/2022] Open
Abstract
Enhancing the polarization of nuclear spins surrounding the nitrogen-vacancy (NV) center in diamond has recently attracted widespread attention due to its various applications. Here we present an analytical formula that not only provides a clear physical picture for the recently observed polarization reversal of strongly coupled(13)C nuclei over a narrow range of magnetic field [H. J. Wang et al., Nat. Commun. 4, 1940 (2013)], but also demonstrates the possibility to strongly polarize weakly coupled (13)C nuclei. This allows sensitive magnetic field control of the (13)C nuclear spin polarization for NMR applications and significant suppression of the (13)C nuclear spin noise to prolong the NV spin coherence time.
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Affiliation(s)
- Ping Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
- Beijing Computational Science Research Center, Beijing 100094, China
| | - Bao Liu
- Beijing Computational Science Research Center, Beijing 100094, China
| | - Wen Yang
- Beijing Computational Science Research Center, Beijing 100094, China
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156
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Buljubasich L, Sánchez CM, Dente AD, Levstein PR, Chattah AK, Pastawski HM. Experimental quantification of decoherence via the Loschmidt echo in a many spin system with scaled dipolar Hamiltonians. J Chem Phys 2015; 143:164308. [PMID: 26520514 DOI: 10.1063/1.4934221] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We performed Loschmidt echo nuclear magnetic resonance experiments to study decoherence under a scaled dipolar Hamiltonian by means of a symmetrical time-reversal pulse sequence denominated Proportionally Refocused Loschmidt (PRL) echo. The many-spin system represented by the protons in polycrystalline adamantane evolves through two steps of evolution characterized by the secular part of the dipolar Hamiltonian, scaled down with a factor |k| and opposite signs. The scaling factor can be varied continuously from 0 to 1/2, giving access to a range of complexity in the dynamics. The experimental results for the Loschmidt echoes showed a spreading of the decay rates that correlate directly to the scaling factors |k|, giving evidence that the decoherence is partially governed by the coherent dynamics. The average Hamiltonian theory was applied to give an insight into the spin dynamics during the pulse sequence. The calculations were performed for every single radio frequency block in contrast to the most widely used form. The first order of the average Hamiltonian numerically computed for an 8-spin system showed decay rates that progressively decrease as the secular dipolar Hamiltonian becomes weaker. Notably, the first order Hamiltonian term neglected by conventional calculations yielded an explanation for the ordering of the experimental decoherence rates. However, there is a strong overall decoherence observed in the experiments which is not reflected by the theoretical results. The fact that the non-inverted terms do not account for this effect is a challenging topic. A number of experiments to further explore the relation of the complete Hamiltonian with this dominant decoherence rate are proposed.
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Affiliation(s)
| | - Claudia M Sánchez
- Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba, Ciudad Universitaria, Córdoba 5000, Argentina
| | - Axel D Dente
- Instituto de Física Enrique Gaviola (IFEG-CONICET), Córdoba 5000, Argentina
| | | | - Ana K Chattah
- Instituto de Física Enrique Gaviola (IFEG-CONICET), Córdoba 5000, Argentina
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157
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Highly selective detection of individual nuclear spins with rotary echo on an electron spin probe. Sci Rep 2015; 5:15402. [PMID: 26497777 PMCID: PMC4620492 DOI: 10.1038/srep15402] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/17/2015] [Indexed: 01/09/2023] Open
Abstract
We consider an electronic spin, such as a nitrogen-vacancy center in diamond, weakly coupled to a large number of nuclear spins, and subjected to the Rabi driving with a periodically alternating phase. We show that by switching the driving phase synchronously with the precession of a given nuclear spin, the interaction to this spin is selectively enhanced, while the rest of the bath remains decoupled. The enhancement is of resonant character. The key feature of the suggested scheme is that the width of the resonance is adjustable, and can be greatly decreased by increasing the driving strength. Thus, the resonance can be significantly narrowed, by a factor of 10–100 in comparison with the existing detection methods. Significant improvement in selectivity is explained analytically and confirmed by direct numerical many-spin simulations. The method can be applied to a wide range of solid-state systems.
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158
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Tanaka T, Knott P, Matsuzaki Y, Dooley S, Yamaguchi H, Munro WJ, Saito S. Proposed Robust Entanglement-Based Magnetic Field Sensor Beyond the Standard Quantum Limit. PHYSICAL REVIEW LETTERS 2015; 115:170801. [PMID: 26551094 DOI: 10.1103/physrevlett.115.170801] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Indexed: 06/05/2023]
Abstract
Recently, there have been significant developments in entanglement-based quantum metrology. However, entanglement is fragile against experimental imperfections, and quantum sensing to beat the standard quantum limit in scaling has not yet been achieved in realistic systems. Here, we show that it is possible to overcome such restrictions so that one can sense a magnetic field with an accuracy beyond the standard quantum limit even under the effect of decoherence, by using a realistic entangled state that can be easily created even with current technology. Our scheme could pave the way for the realizations of practical entanglement-based magnetic field sensors.
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Affiliation(s)
- Tohru Tanaka
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
- Department of Physics, Waseda University, Tokyo 169-8555, Japan
| | - Paul Knott
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Yuichiro Matsuzaki
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Shane Dooley
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
- National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan
| | - Hiroshi Yamaguchi
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - William J Munro
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Shiro Saito
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
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159
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Yang WL, An JH, Zhang CJ, Chen CY, Oh CH. Dynamics of quantum correlation between separated nitrogen-vacancy centers embedded in plasmonic waveguide. Sci Rep 2015; 5:15513. [PMID: 26493045 PMCID: PMC4616030 DOI: 10.1038/srep15513] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 09/28/2015] [Indexed: 11/24/2022] Open
Abstract
We investigate the dynamics of quantum correlation between two separated nitrogen vacancy centers (NVCs) placed near a one-dimensional plasmonic waveguide. As a common medium of the radiation field of NVCs propagating, the plasmonic waveguide can dynamically induce quantum correlation between the two NVCs. It is interesting to find that such dynamically induced quantum correlation can be preserved in the long-time steady state by locally applying individual driving on the two NVCs. In particular, we also show that a large degree of quantum correlation can be established by this scheme even when the distance between the NVCs is much larger than their operating wavelength. This feature may open new perspectives for devising active decoherence-immune solid-state optical devices and long-distance NVC-based quantum networks in the context of plasmonic quantum electrodynamics.
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Affiliation(s)
- Wan-li Yang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China.,Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
| | - Jun-Hong An
- Center for Interdisciplinary Studies &Key Laboratory for Magnetism and Magnetic Materials of the MoE, Lanzhou University, Lanzhou 730000, China.,Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
| | - Cheng-jie Zhang
- Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
| | - Chang-yong Chen
- Department of Physics, Shaoguan University, Shaoguan, Guangdong 512005, China
| | - C H Oh
- Centre for Quantum Technologies, National University of Singapore, Singapore 117543, Singapore
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160
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Bourgeois E, Jarmola A, Siyushev P, Gulka M, Hruby J, Jelezko F, Budker D, Nesladek M. Photoelectric detection of electron spin resonance of nitrogen-vacancy centres in diamond. Nat Commun 2015; 6:8577. [PMID: 26486014 PMCID: PMC4639813 DOI: 10.1038/ncomms9577] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 09/08/2015] [Indexed: 12/22/2022] Open
Abstract
The readout of negatively charged nitrogen-vacancy centre electron spins is essential for applications in quantum computation, metrology and sensing. Conventional readout protocols are based on the detection of photons emitted from nitrogen-vacancy centres, a process limited by the efficiency of photon collection. We report on an alternative principle for detecting the magnetic resonance of nitrogen-vacancy centres, allowing the direct photoelectric readout of nitrogen-vacancy centres spin state in an all-diamond device. The photocurrent detection of magnetic resonance scheme is based on the detection of charge carriers promoted to the conduction band of diamond by two-photon ionization of nitrogen-vacancy centres. The optical and photoelectric detection of magnetic resonance are compared, by performing both types of measurements simultaneously. The minima detected in the measured photocurrent at resonant microwave frequencies are attributed to the spin-dependent ionization dynamics of nitrogen-vacancy, originating from spin-selective non-radiative transitions to the metastable singlet state. Nitrogen-vacancy colour centre defects in diamond are one possible host for qubits, but such an application requires a method for reading out the colour centre spin state. Here, the authors demonstrate a photoelectric readout technique of the magnetic resonances of these colour centres.
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Affiliation(s)
- E Bourgeois
- IMOMEC division, IMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium.,Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
| | - A Jarmola
- Department of Physics, University of California, Berkeley, California 94720-7300, USA
| | - P Siyushev
- Institute for Quantum Optics and IQST, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany
| | - M Gulka
- Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium.,Czech Technical University in Prague, Sitna sq. 3105, 272 01, Kladno, Czech Republic
| | - J Hruby
- Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium.,Czech Technical University in Prague, Sitna sq. 3105, 272 01, Kladno, Czech Republic
| | - F Jelezko
- Institute for Quantum Optics and IQST, Ulm University, Albert-Einstein-Allee 11, D-89081 Ulm, Germany
| | - D Budker
- Helmholtz Institute, Johannes Gutenberg University, D-55099, Mainz, Germany.,Department of Physics, University of California, Berkeley, California 94720-7300, USA
| | - M Nesladek
- IMOMEC division, IMEC, Wetenschapspark 1, B-3590 Diepenbeek, Belgium.,Institute for Materials Research (IMO), Hasselt University, Wetenschapspark 1, B-3590 Diepenbeek, Belgium
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161
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Abstract
The holographic principle states that the information about a volume of a system is encoded on the boundary surface of the volume. Holography appears in many branches of physics, such as optics, electromagnetism, many-body physics, quantum gravity, and string theory. Here we show that holography is also an underlying principle in thermodynamics, a most important foundation of physics. The thermodynamics of a system is fully determined by its partition function. We prove that the partition function of a finite but arbitrarily large system is an analytic function on the complex plane of physical parameters, and therefore the partition function in a region on the complex plane is uniquely determined by its values along the boundary. The thermodynamic holography has applications in studying thermodynamics of nano-scale systems (such as molecule engines, nano-generators and macromolecules) and provides a new approach to many-body physics.
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162
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Freitas JCC, Scopel WL, Paz WS, Bernardes LV, Cunha-Filho FE, Speglich C, Araújo-Moreira FM, Pelc D, Cvitanić T, Požek M. Determination of the hyperfine magnetic field in magnetic carbon-based materials: DFT calculations and NMR experiments. Sci Rep 2015; 5:14761. [PMID: 26434597 PMCID: PMC4593005 DOI: 10.1038/srep14761] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 09/03/2015] [Indexed: 11/25/2022] Open
Abstract
The prospect of carbon-based magnetic materials is of immense fundamental and practical importance, and information on atomic-scale features is required for a better understanding of the mechanisms leading to carbon magnetism. Here we report the first direct detection of the microscopic magnetic field produced at (13)C nuclei in a ferromagnetic carbon material by zero-field nuclear magnetic resonance (NMR). Electronic structure calculations carried out in nanosized model systems with different classes of structural defects show a similar range of magnetic field values (18-21 T) for all investigated systems, in agreement with the NMR experiments. Our results are strong evidence of the intrinsic nature of defect-induced magnetism in magnetic carbons and establish the magnitude of the hyperfine magnetic field created in the neighbourhood of the defects that lead to magnetic order in these materials.
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Affiliation(s)
- Jair C. C. Freitas
- Department of Physics, Federal University of Espírito Santo (UFES), Av. Fernando Ferrari, 514, 29075-910, Vitória, ES, Brazil
| | - Wanderlã L. Scopel
- Department of Physics, Federal University of Espírito Santo (UFES), Av. Fernando Ferrari, 514, 29075-910, Vitória, ES, Brazil
- Department of Exact Sciences, Federal Fluminense University, 27255-250, Volta Redonda, RJ, Brazil
| | - Wendel S. Paz
- Department of Physics, Federal University of Espírito Santo (UFES), Av. Fernando Ferrari, 514, 29075-910, Vitória, ES, Brazil
| | - Leandro V. Bernardes
- Department of Physics, Federal University of São Carlos (UFSCar), P.O. Box 676, 13565-905, São Carlos, SP, Brazil
| | - Francisco E. Cunha-Filho
- Department of Physics, Federal University of São Carlos (UFSCar), P.O. Box 676, 13565-905, São Carlos, SP, Brazil
| | - Carlos Speglich
- Department of Physics, Federal University of São Carlos (UFSCar), P.O. Box 676, 13565-905, São Carlos, SP, Brazil
| | - Fernando M. Araújo-Moreira
- Department of Physics, Federal University of São Carlos (UFSCar), P.O. Box 676, 13565-905, São Carlos, SP, Brazil
| | - Damjan Pelc
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička 32, HR-10000, Zagreb, Croatia
| | - Tonči Cvitanić
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička 32, HR-10000, Zagreb, Croatia
| | - Miroslav Požek
- Department of Physics, Faculty of Science, University of Zagreb, Bijenička 32, HR-10000, Zagreb, Croatia
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163
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Wang Y, Dolde F, Biamonte J, Babbush R, Bergholm V, Yang S, Jakobi I, Neumann P, Aspuru-Guzik A, Whitfield JD, Wrachtrup J. Quantum Simulation of Helium Hydride Cation in a Solid-State Spin Register. ACS NANO 2015; 9:7769-7774. [PMID: 25905564 DOI: 10.1021/acsnano.5b01651] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ab initio computation of molecular properties is one of the most promising applications of quantum computing. While this problem is widely believed to be intractable for classical computers, efficient quantum algorithms exist which have the potential to vastly accelerate research throughput in fields ranging from material science to drug discovery. Using a solid-state quantum register realized in a nitrogen-vacancy (NV) defect in diamond, we compute the bond dissociation curve of the minimal basis helium hydride cation, HeH(+). Moreover, we report an energy uncertainty (given our model basis) of the order of 10(-14) hartree, which is 10 orders of magnitude below the desired chemical precision. As NV centers in diamond provide a robust and straightforward platform for quantum information processing, our work provides an important step toward a fully scalable solid-state implementation of a quantum chemistry simulator.
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Affiliation(s)
- Ya Wang
- Third Institute of Physics, Research Center Scope and IQST, University of Stuttgart , 70569 Stuttgart, Germany
| | - Florian Dolde
- Third Institute of Physics, Research Center Scope and IQST, University of Stuttgart , 70569 Stuttgart, Germany
| | | | - Ryan Babbush
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138 United States
- Google , 150 Main Street, Venice Beach, California 90291, United States
| | | | - Sen Yang
- Third Institute of Physics, Research Center Scope and IQST, University of Stuttgart , 70569 Stuttgart, Germany
| | - Ingmar Jakobi
- Third Institute of Physics, Research Center Scope and IQST, University of Stuttgart , 70569 Stuttgart, Germany
| | - Philipp Neumann
- Third Institute of Physics, Research Center Scope and IQST, University of Stuttgart , 70569 Stuttgart, Germany
| | - Alán Aspuru-Guzik
- Department of Chemistry and Chemical Biology, Harvard University , Cambridge, Massachusetts 02138 United States
| | - James D Whitfield
- Department of Physics, Vienna Center for Quantum Science and Technology, University of Vienna , Boltzmanngasse 5, Vienna 1090, Austria
| | - Jörg Wrachtrup
- Third Institute of Physics, Research Center Scope and IQST, University of Stuttgart , 70569 Stuttgart, Germany
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164
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Khanaliloo B, Mitchell M, Hryciw AC, Barclay PE. High-Q/V Monolithic Diamond Microdisks Fabricated with Quasi-isotropic Etching. NANO LETTERS 2015; 15:5131-5136. [PMID: 26134379 DOI: 10.1021/acs.nanolett.5b01346] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optical microcavities enhance light-matter interactions and are essential for many experiments in solid state quantum optics, optomechanics, and nonlinear optics. Single crystal diamond microcavities are particularly sought after for applications involving diamond quantum emitters, such as nitrogen vacancy centers, and for experiments that benefit from diamond's excellent optical and mechanical properties. Light-matter coupling rates in experiments involving microcavities typically scale with Q/V, where Q and V are the microcavity quality-factor and mode-volume, respectively. Here we demonstrate that microdisk whispering gallery mode cavities with high Q/V can be fabricated directly from bulk single crystal diamond. By using a quasi-isotropic oxygen plasma to etch along diamond crystal planes and undercut passivated diamond structures, we create monolithic diamond microdisks. Fiber taper based measurements show that these devices support TE- and TM-like optical modes with Q > 1.1 × 10(5) and V < 11(λ/n) (3) at a wavelength of 1.5 μm.
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Affiliation(s)
- Behzad Khanaliloo
- †Department of Physics and Astronomy and Institute for Quantum Science and Technology, University of Calgary, Calgary, AB T2N 1N4, Canada
- ‡National Institute for Nanotechnology, 11421 Saskatchewan Drive Northwest, Edmonton, AB T6G 2M9, Canada
| | - Matthew Mitchell
- †Department of Physics and Astronomy and Institute for Quantum Science and Technology, University of Calgary, Calgary, AB T2N 1N4, Canada
- ‡National Institute for Nanotechnology, 11421 Saskatchewan Drive Northwest, Edmonton, AB T6G 2M9, Canada
| | - Aaron C Hryciw
- ‡National Institute for Nanotechnology, 11421 Saskatchewan Drive Northwest, Edmonton, AB T6G 2M9, Canada
- §nanoFAB Facility, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Paul E Barclay
- †Department of Physics and Astronomy and Institute for Quantum Science and Technology, University of Calgary, Calgary, AB T2N 1N4, Canada
- ‡National Institute for Nanotechnology, 11421 Saskatchewan Drive Northwest, Edmonton, AB T6G 2M9, Canada
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165
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Wang WB, Zu C, He L, Zhang WG, Duan LM. Memory-built-in quantum cloning in a hybrid solid-state spin register. Sci Rep 2015; 5:12203. [PMID: 26178617 PMCID: PMC4503958 DOI: 10.1038/srep12203] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2015] [Accepted: 06/17/2015] [Indexed: 11/09/2022] Open
Abstract
As a way to circumvent the quantum no-cloning theorem, approximate quantum cloning protocols have received wide attention with remarkable applications. Copying of quantum states to memory qubits provides an important strategy for eavesdropping in quantum cryptography. We report an experiment that realizes cloning of quantum states from an electron spin to a nuclear spin in a hybrid solid-state spin register with near-optimal fidelity. The nuclear spin provides an ideal memory qubit at room temperature, which stores the cloned quantum states for a millisecond under ambient conditions, exceeding the lifetime of the original quantum state carried by the electron spin by orders of magnitude. The realization of a cloning machine with built-in quantum memory provides a key step for application of quantum cloning in quantum information science.
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Affiliation(s)
- W-B Wang
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, PR China
| | - C Zu
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, PR China
| | - L He
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, PR China
| | - W-G Zhang
- Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, PR China
| | - L-M Duan
- 1] Center for Quantum Information, IIIS, Tsinghua University, Beijing 100084, PR China [2] Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
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166
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Active charge state control of single NV centres in diamond by in-plane Al-Schottky junctions. Sci Rep 2015; 5:12160. [PMID: 26177799 PMCID: PMC4503995 DOI: 10.1038/srep12160] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 05/28/2015] [Indexed: 11/23/2022] Open
Abstract
In this paper, we demonstrate an active control of the charge state of a single nitrogen-vacancy (NV) centre by using in-plane Schottky-diode geometries with aluminium on hydrogen-terminated diamond surface. A switching between NV+, NV0 and NV− can be performed with the Al-gates which apply electric fields in the hole depletion region of the Schottky junction that induces a band bending modulation, thereby shifting the Fermi-level over NV charge transition levels. We simulated the in-plane band structure of the Schottky junction with the Software ATLAS by solving the drift-diffusion model and the Poisson-equation self-consistently. We simulated the IV-characteristics, calculated the width of the hole depletion region, the position of the Fermi-level intersection with the NV charge transition levels for different reverse bias voltages applied on the Al-gate. We can show that the field-induced band bending modulation in the depletion region causes a shifting of the Fermi-level over NV charge transition levels in such a way that the charge state of a single NV centre and thus its electrical and optical properties is tuned. In addition, the NV centre should be approx. 1–2 μm away from the Al-edge in order to be switched with moderate bias voltages.
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167
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Plakhotnik T, Aman H, Chang HC. All-optical single-nanoparticle ratiometric thermometry with a noise floor of 0.3 K Hz(-1/2). NANOTECHNOLOGY 2015; 26:245501. [PMID: 26011506 DOI: 10.1088/0957-4484/26/24/245501] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We demonstrate a temperature noise floor of 0.3 K Hz(-1/2) and a long-term stability better than 0.6 K (peak-to-peak value) using a single crystal of diamond smaller than 50 nm across and containing about 100 nitrogen-vacancy centres as a temperature sensor. We compare the achieved characteristics to other single-particle sensors and show that it is one of the best ratiometric all-optical nano-probes of temperature to date.
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Affiliation(s)
- Taras Plakhotnik
- School of Mathematics and Physics, The University of Queensland, St Lucia, QLD 4072, Australia
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168
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Goldman ML, Sipahigil A, Doherty MW, Yao NY, Bennett SD, Markham M, Twitchen DJ, Manson NB, Kubanek A, Lukin MD. Phonon-induced population dynamics and intersystem crossing in nitrogen-vacancy centers. PHYSICAL REVIEW LETTERS 2015; 114:145502. [PMID: 25910136 DOI: 10.1103/physrevlett.114.145502] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2014] [Indexed: 06/04/2023]
Abstract
We report direct measurement of population dynamics in the excited state manifold of a nitrogen-vacancy (NV) center in diamond. We quantify the phonon-induced mixing rate and demonstrate that it can be completely suppressed at low temperatures. Further, we measure the intersystem crossing (ISC) rate for different excited states and develop a theoretical model that unifies the phonon-induced mixing and ISC mechanisms. We find that our model is in excellent agreement with experiment and that it can be used to predict unknown elements of the NV center's electronic structure. We discuss the model's implications for enhancing the NV center's performance as a room-temperature sensor.
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Affiliation(s)
- M L Goldman
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - A Sipahigil
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M W Doherty
- Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Australian Capital Territory 0200, Australia
| | - N Y Yao
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - S D Bennett
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M Markham
- Element Six Ltd, Kings Ride Park, Ascot SL5 8BP, United Kingdom
| | - D J Twitchen
- Element Six Ltd, Kings Ride Park, Ascot SL5 8BP, United Kingdom
| | - N B Manson
- Laser Physics Centre, Research School of Physics and Engineering, Australian National University, Australian Capital Territory 0200, Australia
| | - A Kubanek
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M D Lukin
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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169
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Liu GQ, Zhang YR, Chang YC, Yue JD, Fan H, Pan XY. Demonstration of entanglement-enhanced phase estimation in solid. Nat Commun 2015; 6:6726. [PMID: 25832364 PMCID: PMC4396365 DOI: 10.1038/ncomms7726] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Accepted: 02/21/2015] [Indexed: 11/09/2022] Open
Abstract
Precise parameter estimation plays a central role in science and technology. The statistical error in estimation can be decreased by repeating measurement, leading to that the resultant uncertainty of the estimated parameter is proportional to the square root of the number of repetitions in accordance with the central limit theorem. Quantum parameter estimation, an emerging field of quantum technology, aims to use quantum resources to yield higher statistical precision than classical approaches. Here we report the first room-temperature implementation of entanglement-enhanced phase estimation in a solid-state system: the nitrogen-vacancy centre in pure diamond. We demonstrate a super-resolving phase measurement with two entangled qubits of different physical realizations: an nitrogen-vacancy centre electron spin and a proximal (13)C nuclear spin. The experimental data shows clearly the uncertainty reduction when entanglement resource is used, confirming the theoretical expectation. Our results represent an elemental demonstration of enhancement of quantum metrology against classical procedure.
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Affiliation(s)
- Gang-Qin Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yu-Ran Zhang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Yan-Chun Chang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jie-Dong Yue
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Heng Fan
- 1] Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [2] Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
| | - Xin-Yu Pan
- 1] Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China [2] Collaborative Innovation Center of Quantum Matter, Beijing 100190, China
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170
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Laucht A, Muhonen JT, Mohiyaddin FA, Kalra R, Dehollain JP, Freer S, Hudson FE, Veldhorst M, Rahman R, Klimeck G, Itoh KM, Jamieson DN, McCallum JC, Dzurak AS, Morello A. Electrically controlling single-spin qubits in a continuous microwave field. SCIENCE ADVANCES 2015; 1:e1500022. [PMID: 26601166 PMCID: PMC4640634 DOI: 10.1126/sciadv.1500022] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 03/14/2015] [Indexed: 05/24/2023]
Abstract
Large-scale quantum computers must be built upon quantum bits that are both highly coherent and locally controllable. We demonstrate the quantum control of the electron and the nuclear spin of a single (31)P atom in silicon, using a continuous microwave magnetic field together with nanoscale electrostatic gates. The qubits are tuned into resonance with the microwave field by a local change in electric field, which induces a Stark shift of the qubit energies. This method, known as A-gate control, preserves the excellent coherence times and gate fidelities of isolated spins, and can be extended to arbitrarily many qubits without requiring multiple microwave sources.
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Affiliation(s)
- Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Juha T. Muhonen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Fahd A. Mohiyaddin
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Rachpon Kalra
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Juan P. Dehollain
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Solomon Freer
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Fay E. Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Menno Veldhorst
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Rajib Rahman
- Network for Computational Nanotechnology, Purdue University, West Lafayette, IN 47907, USA
| | - Gerhard Klimeck
- Network for Computational Nanotechnology, Purdue University, West Lafayette, IN 47907, USA
| | - Kohei M. Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
| | - David N. Jamieson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jeffrey C. McCallum
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew S. Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, New South Wales 2052, Australia
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171
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Matsuzaki Y, Zhu X, Kakuyanagi K, Toida H, Shimo-Oka T, Mizuochi N, Nemoto K, Semba K, Munro WJ, Yamaguchi H, Saito S. Improving the coherence time of a quantum system via a coupling to a short-lived system. PHYSICAL REVIEW LETTERS 2015; 114:120501. [PMID: 25860725 DOI: 10.1103/physrevlett.114.120501] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Indexed: 06/04/2023]
Abstract
In this Letter, we propose a counterintuitive use of a hybrid system where the coherence time of a quantum system can be significantly improved by coupling it with a system of a shorter coherence time. Coupling a two-level system with a single nitrogen-vacancy (NV^{-}) center, a dark state of the NV^{-} center naturally forms after the hybridization. We show that this dark state becomes robust against noise due to the coupling even when the coherence time of the two-level system is much shorter than that of the NV^{-} center. Our proposal opens a new way to use a quantum hybrid system for the realization of robust quantum information processing.
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Affiliation(s)
- Yuichiro Matsuzaki
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Xiaobo Zhu
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Kosuke Kakuyanagi
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Hiraku Toida
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Takaaki Shimo-Oka
- Graduate School of Engineering Science, University of Osaka, 1-3 Machikane-yama, Toyonaka, Osaka 560-8531, Japan
| | - Norikazu Mizuochi
- Graduate School of Engineering Science, University of Osaka, 1-3 Machikane-yama, Toyonaka, Osaka 560-8531, Japan
| | - Kae Nemoto
- National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan
| | - Kouichi Semba
- National Institute of Information and Communications Technology, Koganei, Tokyo 184-8795, Japan
| | - William J Munro
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Hiroshi Yamaguchi
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Shiro Saito
- NTT Basic Research Laboratories, NTT Corporation, 3-1 Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
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172
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Borregaard J, Kómár P, Kessler EM, Sørensen AS, Lukin MD. Heralded quantum gates with integrated error detection in optical cavities. PHYSICAL REVIEW LETTERS 2015; 114:110502. [PMID: 25839248 DOI: 10.1103/physrevlett.114.110502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2015] [Indexed: 06/04/2023]
Abstract
We propose and analyze heralded quantum gates between qubits in optical cavities. They employ an auxiliary qubit to report if a successful gate occurred. In this manner, the errors, which would have corrupted a deterministic gate, are converted into a nonunity probability of success: once successful, the gate has a much higher fidelity than a similar deterministic gate. Specifically, we describe that a heralded, near-deterministic controlled phase gate (CZ gate) with the conditional error arbitrarily close to zero and the success probability that approaches unity as the cooperativity of the system, C, becomes large. Furthermore, we describe an extension to near-deterministic N-qubit Toffoli gate with a favorable error scaling. These gates can be directly employed in quantum repeater networks to facilitate near-ideal entanglement swapping, thus greatly speeding up the entanglement distribution.
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Affiliation(s)
- J Borregaard
- The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark
| | - P Kómár
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - E M Kessler
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
- ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
| | - A S Sørensen
- The Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark
| | - M D Lukin
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
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173
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Abstract
An extensively pursued current direction of research in physics aims at the development of practical technologies that exploit the effects of quantum mechanics. As part of this ongoing effort, devices for quantum information processing, secure communication, and high-precision sensing are being implemented with diverse systems, ranging from photons, atoms, and spins to mesoscopic superconducting and nanomechanical structures. Their physical properties make some of these systems better suited than others for specific tasks; thus, photons are well suited for transmitting quantum information, weakly interacting spins can serve as long-lived quantum memories, and superconducting elements can rapidly process information encoded in their quantum states. A central goal of the envisaged quantum technologies is to develop devices that can simultaneously perform several of these tasks, namely, reliably store, process, and transmit quantum information. Hybrid quantum systems composed of different physical components with complementary functionalities may provide precisely such multitasking capabilities. This article reviews some of the driving theoretical ideas and first experimental realizations of hybrid quantum systems and the opportunities and challenges they present and offers a glance at the near- and long-term perspectives of this fascinating and rapidly expanding field.
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174
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Morello A. Quantum spintronics: Single spins in silicon carbide. NATURE MATERIALS 2015; 14:135-136. [PMID: 25437257 DOI: 10.1038/nmat4171] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Affiliation(s)
- Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney New South Wales 2052, Australia
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175
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Kupchak C, Mittiga T, Jordaan B, Namazi M, Nölleke C, Figueroa E. Room-temperature single-photon level memory for polarization states. Sci Rep 2015; 5:7658. [PMID: 25564048 PMCID: PMC4288213 DOI: 10.1038/srep07658] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 12/03/2014] [Indexed: 11/09/2022] Open
Abstract
An optical quantum memory is a stationary device that is capable of storing and recreating photonic qubits with a higher fidelity than any classical device. Thus far, these two requirements have been fulfilled for polarization qubits in systems based on cold atoms and cryogenically cooled crystals. Here, we report a room-temperature memory capable of storing arbitrary polarization qubits with a signal-to-background ratio higher than 1 and an average fidelity surpassing the classical benchmark for weak laser pulses containing 1.6 photons on average, without taking into account non-unitary operation. Our results demonstrate that a common vapor cell can reach the low background noise levels necessary for polarization qubit storage using single-photon level light, and propels atomic-vapor systems towards a level of functionality akin to other quantum information processing architectures.
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Affiliation(s)
- Connor Kupchak
- Department of Physics and Astronomy, Stony Brook University, New York 11794-3800, USA
| | - Thomas Mittiga
- Department of Physics and Astronomy, Stony Brook University, New York 11794-3800, USA
| | - Bertus Jordaan
- Department of Physics and Astronomy, Stony Brook University, New York 11794-3800, USA
| | - Mehdi Namazi
- Department of Physics and Astronomy, Stony Brook University, New York 11794-3800, USA
| | - Christian Nölleke
- Department of Physics and Astronomy, Stony Brook University, New York 11794-3800, USA
| | - Eden Figueroa
- Department of Physics and Astronomy, Stony Brook University, New York 11794-3800, USA
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176
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Blok MS, Kalb N, Reiserer A, Taminiau TH, Hanson R. Towards quantum networks of single spins: analysis of a quantum memory with an optical interface in diamond. Faraday Discuss 2015; 184:173-82. [DOI: 10.1039/c5fd00113g] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Single defect centers in diamond have emerged as a powerful platform for quantum optics experiments and quantum information processing tasks. Connecting spatially separated nodes via optical photons into a quantum network will enable distributed quantum computing and long-range quantum communication. Initial experiments on trapped atoms and ions as well as defects in diamond have demonstrated entanglement between two nodes over several meters. To realize multi-node networks, additional quantum bit systems that store quantum states while new entanglement links are established are highly desirable. Such memories allow for entanglement distillation, purification and quantum repeater protocols that extend the size, speed and distance of the network. However, to be effective, the memory must be robust against the entanglement generation protocol, which typically must be repeated many times. Here we evaluate the prospects of using carbon nuclear spins in diamond as quantum memories that are compatible with quantum networks based on single nitrogen vacancy (NV) defects in diamond. We present a theoretical framework to describe the dephasing of the nuclear spins under repeated generation of NV spin-photon entanglement and show that quantum states can be stored during hundreds of repetitions using typical experimental coupling parameters. This result demonstrates that nuclear spins with weak hyperfine couplings are promising quantum memories for quantum networks.
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Affiliation(s)
- M. S. Blok
- QuTech and Kavli Institute of Nanoscience
- Delft University of Technology
- 2600 GA Delft
- The Netherlands
| | - N. Kalb
- QuTech and Kavli Institute of Nanoscience
- Delft University of Technology
- 2600 GA Delft
- The Netherlands
| | - A. Reiserer
- QuTech and Kavli Institute of Nanoscience
- Delft University of Technology
- 2600 GA Delft
- The Netherlands
| | - T. H. Taminiau
- QuTech and Kavli Institute of Nanoscience
- Delft University of Technology
- 2600 GA Delft
- The Netherlands
| | - R. Hanson
- QuTech and Kavli Institute of Nanoscience
- Delft University of Technology
- 2600 GA Delft
- The Netherlands
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177
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Barskaya IY, Veber SL, Fokin SV, Tretyakov EV, Bagryanskaya EG, Ovcharenko VI, Fedin MV. Structural specifics of light-induced metastable states in copper(ii)–nitroxide molecular magnets. Dalton Trans 2015; 44:20883-8. [DOI: 10.1039/c5dt03683f] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Although thermally- and light-induced structures of molecular magnets Cu(hfac)2LR are principally similar, FTIR reveals differences in packing of peripheral groups.
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Affiliation(s)
- I. Yu. Barskaya
- International Tomography Center SB RAS
- Novosibirsk
- Russia
- Novosibirsk State University
- Novosibirsk
| | - S. L. Veber
- International Tomography Center SB RAS
- Novosibirsk
- Russia
- Novosibirsk State University
- Novosibirsk
| | - S. V. Fokin
- International Tomography Center SB RAS
- Novosibirsk
- Russia
| | - E. V. Tretyakov
- International Tomography Center SB RAS
- Novosibirsk
- Russia
- Novosibirsk State University
- Novosibirsk
| | - E. G. Bagryanskaya
- Novosibirsk State University
- Novosibirsk
- Russia
- N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS
- Novosibirsk
| | | | - M. V. Fedin
- International Tomography Center SB RAS
- Novosibirsk
- Russia
- Novosibirsk State University
- Novosibirsk
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178
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Rogers LJ, Jahnke KD, Metsch MH, Sipahigil A, Binder JM, Teraji T, Sumiya H, Isoya J, Lukin MD, Hemmer P, Jelezko F. All-optical initialization, readout, and coherent preparation of single silicon-vacancy spins in diamond. PHYSICAL REVIEW LETTERS 2014; 113:263602. [PMID: 25615330 DOI: 10.1103/physrevlett.113.263602] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2014] [Indexed: 06/04/2023]
Abstract
The silicon-vacancy (SiV-) color center in diamond has attracted attention because of its unique optical properties. It exhibits spectral stability and indistinguishability that facilitate efficient generation of photons capable of demonstrating quantum interference. Here we show optical initialization and readout of electronic spin in a single SiV- center with a spin relaxation time of T1=2.4±0.2 ms. Coherent population trapping (CPT) is used to demonstrate coherent preparation of dark superposition states with a spin coherence time of T2⋆=35±3 ns. This is fundamentally limited by orbital relaxation, and an understanding of this process opens the way to extend coherence by engineering interactions with phonons. Hyperfine structure is observed in CPT measurements with the 29Si isotope which allows access to nuclear spin. These results establish the SiV- center as a solid-state spin-photon interface.
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Affiliation(s)
- Lachlan J Rogers
- Institute for Quantum Optics and Center for Integrated Quantum Science and Technology (IQst), Ulm University, Ulm D-89081, Germany
| | - Kay D Jahnke
- Institute for Quantum Optics and Center for Integrated Quantum Science and Technology (IQst), Ulm University, Ulm D-89081, Germany
| | - Mathias H Metsch
- Institute for Quantum Optics and Center for Integrated Quantum Science and Technology (IQst), Ulm University, Ulm D-89081, Germany
| | - Alp Sipahigil
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Jan M Binder
- Institute for Quantum Optics and Center for Integrated Quantum Science and Technology (IQst), Ulm University, Ulm D-89081, Germany
| | - Tokuyuki Teraji
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Hitoshi Sumiya
- Advanced Materials R & D Laboratories, Sumitomo Electric Industries Limited, Itami, Hyogo 664-0016, Japan
| | - Junichi Isoya
- Research Center for Knowledge Communities, University of Tsukuba, 1-2 Kasuga, Tsukuba, Ibaraki 305-8550, Japan
| | - Mikhail D Lukin
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - Philip Hemmer
- Electrical & Computer Engineering Department, Texas A&M University, College Station, Texas 77843, USA
| | - Fedor Jelezko
- Institute for Quantum Optics and Center for Integrated Quantum Science and Technology (IQst), Ulm University, Ulm D-89081, Germany
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179
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180
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Golter DA, Baldwin TK, Wang H. Protecting a solid-state spin from decoherence using dressed spin states. PHYSICAL REVIEW LETTERS 2014; 113:237601. [PMID: 25526157 DOI: 10.1103/physrevlett.113.237601] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2014] [Indexed: 06/04/2023]
Abstract
We report experimental studies of dressing an electron spin in diamond with resonant and continuous microwave fields to protect the electron spin from magnetic fluctuations induced by the nuclear spin bath. We use optical coherent population trapping (CPT) to probe the energy level structure, optically induced spin transitions, and spin decoherence rates of the dressed spin states. Dressing an electron spin with resonant microwaves at a coupling rate near 1 MHz leads to a 50 times reduction in the linewidth of the spin transition underlying the CPT process, limited by transit-time broadening. Compared with dynamical decoupling, where effects of the bath are averaged out at specific times, the dressed spin state provides a continuous protection from decoherence.
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Affiliation(s)
- D Andrew Golter
- Department of Physics, University of Oregon, Eugene, Oregon 97403, USA
| | - Thomas K Baldwin
- Department of Physics, University of Oregon, Eugene, Oregon 97403, USA
| | - Hailin Wang
- Department of Physics, University of Oregon, Eugene, Oregon 97403, USA
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181
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Muhonen JT, Dehollain JP, Laucht A, Hudson FE, Kalra R, Sekiguchi T, Itoh KM, Jamieson DN, McCallum JC, Dzurak AS, Morello A. Storing quantum information for 30 seconds in a nanoelectronic device. NATURE NANOTECHNOLOGY 2014; 9:986-91. [PMID: 25305745 DOI: 10.1038/nnano.2014.211] [Citation(s) in RCA: 154] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 08/22/2014] [Indexed: 05/14/2023]
Abstract
The spin of an electron or a nucleus in a semiconductor naturally implements the unit of quantum information--the qubit. In addition, because semiconductors are currently used in the electronics industry, developing qubits in semiconductors would be a promising route to realize scalable quantum information devices. The solid-state environment, however, may provide deleterious interactions between the qubit and the nuclear spins of surrounding atoms, or charge and spin fluctuations arising from defects in oxides and interfaces. For materials such as silicon, enrichment of the spin-zero (28)Si isotope drastically reduces spin-bath decoherence. Experiments on bulk spin ensembles in (28)Si crystals have indeed demonstrated extraordinary coherence times. However, it remained unclear whether these would persist at the single-spin level, in gated nanostructures near amorphous interfaces. Here, we present the coherent operation of individual (31)P electron and nuclear spin qubits in a top-gated nanostructure, fabricated on an isotopically engineered (28)Si substrate. The (31)P nuclear spin sets the new benchmark coherence time (>30 s with Carr-Purcell-Meiboom-Gill (CPMG) sequence) of any single qubit in the solid state and reaches >99.99% control fidelity. The electron spin CPMG coherence time exceeds 0.5 s, and detailed noise spectroscopy indicates that--contrary to widespread belief--it is not limited by the proximity to an interface. Instead, decoherence is probably dominated by thermal and magnetic noise external to the device, and is thus amenable to further improvement.
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Affiliation(s)
- Juha T Muhonen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Juan P Dehollain
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Arne Laucht
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Fay E Hudson
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Rachpon Kalra
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Takeharu Sekiguchi
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, 223-8522, Japan
| | - Kohei M Itoh
- School of Fundamental Science and Technology, Keio University, 3-14-1 Hiyoshi, 223-8522, Japan
| | - David N Jamieson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Jeffrey C McCallum
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew S Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
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182
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Dąbrowski M, Chrapkiewicz R, Wasilewski W. Hamiltonian design in readout from room-temperature Raman atomic memory. OPTICS EXPRESS 2014; 22:26076-26090. [PMID: 25401640 DOI: 10.1364/oe.22.026076] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We present an experimental demonstration of the Hamiltonian manipulation in light-atom interface in Raman-type warm rubidium-87 vapor atomic memory. By adjusting the detuning of the driving beam we varied the relative contributions of the Stokes and anti-Stokes scattering to the process of four-wave mixing which reads out a spatially multimode state of atomic memory. We measured the temporal evolution of the readout fields and the spatial intensity correlations between write-in and readout as a function of detuning with the use of an intensified camera. The correlation maps enabled us to resolve between the anti-Stokes and the Stokes scattering and to quantify their contributions. Our experimental results agree quantitatively with a simple, plane-wave theoretical model we provide. They allow for a simple interpretation of the coaction of the anti-Stokes and the Stokes scattering at the readout stage. The Stokes contribution yields additional, adjustable gain at the readout stage, albeit with inevitable extra noise. Here we provide a simple and useful framework to trace it and the results can be utilized in the existing atomic memories setups. Furthermore, the shown Hamiltonian manipulation offers a broad range of atom-light interfaces readily applicable in current and future quantum protocols with atomic ensembles.
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183
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Loretz M, Rosskopf T, Boss JM, Pezzagna S, Meijer J, Degen CL. RETRACTED: Single-proton spin detection by diamond magnetometry. Science 2014; aheadofprint:1259464. [PMID: 25323696 DOI: 10.1126/science.1259464] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Extending magnetic resonance imaging to the atomic scale has been a long-standing aspiration, driven by the prospect of directly mapping atomic positions in molecules with three-dimensional spatial resolution. We report detection of individual, isolated proton spins by a nitrogen-vacancy (NV) center in a diamond chip covered by an inorganic salt. The single-proton identity was confirmed by the Zeeman effect and by a quantum coherent rotation of the weakly coupled nuclear spin. Using the hyperfine field of the NV center as an imaging gradient, we determined proton-NV distances of less than 1 nm.
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Affiliation(s)
- M Loretz
- Department of Physics, ETH Zurich, Otto Stern Weg 1, 8093 Zurich, Switzerland
| | - T Rosskopf
- Department of Physics, ETH Zurich, Otto Stern Weg 1, 8093 Zurich, Switzerland
| | - J M Boss
- Department of Physics, ETH Zurich, Otto Stern Weg 1, 8093 Zurich, Switzerland
| | - S Pezzagna
- Institute for Experimental Physics II, Department of Nuclear Solid State Physics, Universität Leipzig, Linnéstrasse 5, D-04103 Leipzig, Germany
| | - J Meijer
- Institute for Experimental Physics II, Department of Nuclear Solid State Physics, Universität Leipzig, Linnéstrasse 5, D-04103 Leipzig, Germany
| | - C L Degen
- Department of Physics, ETH Zurich, Otto Stern Weg 1, 8093 Zurich, Switzerland.
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184
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Pfender M, Aslam N, Waldherr G, Neumann P, Wrachtrup J. Single-spin stochastic optical reconstruction microscopy. Proc Natl Acad Sci U S A 2014; 111:14669-74. [PMID: 25267655 PMCID: PMC4205624 DOI: 10.1073/pnas.1404907111] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
We experimentally demonstrate precision addressing of single-quantum emitters by combined optical microscopy and spin resonance techniques. To this end, we use nitrogen vacancy (NV) color centers in diamond confined within a few ten nanometers as individually resolvable quantum systems. By developing a stochastic optical reconstruction microscopy (STORM) technique for NV centers, we are able to simultaneously perform sub-diffraction-limit imaging and optically detected spin resonance (ODMR) measurements on NV spins. This allows the assignment of spin resonance spectra to individual NV center locations with nanometer-scale resolution and thus further improves spatial discrimination. For example, we resolved formerly indistinguishable emitters by their spectra. Furthermore, ODMR spectra contain metrology information allowing for sub-diffraction-limit sensing of, for instance, magnetic or electric fields with inherently parallel data acquisition. As an example, we have detected nuclear spins with nanometer-scale precision. Finally, we give prospects of how this technique can evolve into a fully parallel quantum sensor for nanometer resolution imaging of delocalized quantum correlations.
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Affiliation(s)
- Matthias Pfender
- Third Institute of Physics, Stuttgart Research Center of Photonic Engineering and Center for Integrated Quantum Science, University of Stuttgart, 70550 Stuttgart, Germany
| | - Nabeel Aslam
- Third Institute of Physics, Stuttgart Research Center of Photonic Engineering and Center for Integrated Quantum Science, University of Stuttgart, 70550 Stuttgart, Germany
| | - Gerald Waldherr
- Third Institute of Physics, Stuttgart Research Center of Photonic Engineering and Center for Integrated Quantum Science, University of Stuttgart, 70550 Stuttgart, Germany
| | - Philipp Neumann
- Third Institute of Physics, Stuttgart Research Center of Photonic Engineering and Center for Integrated Quantum Science, University of Stuttgart, 70550 Stuttgart, Germany
| | - Jörg Wrachtrup
- Third Institute of Physics, Stuttgart Research Center of Photonic Engineering and Center for Integrated Quantum Science, University of Stuttgart, 70550 Stuttgart, Germany
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185
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Dréau A, Jamonneau P, Gazzano O, Kosen S, Roch JF, Maze JR, Jacques V. Probing the dynamics of a nuclear spin bath in diamond through time-resolved central spin magnetometry. PHYSICAL REVIEW LETTERS 2014; 113:137601. [PMID: 25302916 DOI: 10.1103/physrevlett.113.137601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Indexed: 06/04/2023]
Abstract
Using fast electron spin resonance spectroscopy of a single nitrogen-vacancy defect in diamond, we demonstrate real-time readout of the Overhauser field produced by its nuclear spin environment under ambient conditions. These measurements enable narrowing the Overhauser field distribution by postselection, corresponding to a conditional preparation of the nuclear spin bath. Correlations of the Overhauser field fluctuations are quantitatively inferred by analyzing the Allan deviation over consecutive measurements. This method allows us to extract the dynamics of weakly coupled nuclear spins of the reservoir.
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Affiliation(s)
- A Dréau
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud and Ecole Normale Supérieure de Cachan, 91405 Orsay, France
| | - P Jamonneau
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud and Ecole Normale Supérieure de Cachan, 91405 Orsay, France
| | - O Gazzano
- Universität des Saarlandes, Fachrichtung 7.2 (Experimentalphysik), Campus E2.6, 66123 Saarbrücken, Germany
| | - S Kosen
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud and Ecole Normale Supérieure de Cachan, 91405 Orsay, France
| | - J-F Roch
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud and Ecole Normale Supérieure de Cachan, 91405 Orsay, France
| | - J R Maze
- Facultad de Física, Pontificia Universidad Católica de Chile, Santiago 7820436, Chile
| | - V Jacques
- Laboratoire Aimé Cotton, CNRS, Université Paris-Sud and Ecole Normale Supérieure de Cachan, 91405 Orsay, France
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186
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Malissa H, Kavand M, Waters DP, van Schooten KJ, Burn PL, Vardeny ZV, Saam B, Lupton JM, Boehme C. Room-temperature coupling between electrical current and nuclear spins in OLEDs. Science 2014; 345:1487-90. [DOI: 10.1126/science.1255624] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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187
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Sipahigil A, Jahnke KD, Rogers LJ, Teraji T, Isoya J, Zibrov AS, Jelezko F, Lukin MD. Indistinguishable photons from separated silicon-vacancy centers in diamond. PHYSICAL REVIEW LETTERS 2014; 113:113602. [PMID: 25259977 DOI: 10.1103/physrevlett.113.113602] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2014] [Indexed: 05/08/2023]
Abstract
We demonstrate that silicon-vacancy (SiV) centers in diamond can be used to efficiently generate coherent optical photons with excellent spectral properties. We show that these features are due to the inversion symmetry associated with SiV centers. The generation of indistinguishable single photons from separated emitters at 5 K is demonstrated in a Hong-Ou-Mandel interference experiment. Prospects for realizing efficient quantum network nodes using SiV centers are discussed.
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Affiliation(s)
- A Sipahigil
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - K D Jahnke
- Institute for Quantum Optics, University Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - L J Rogers
- Institute for Quantum Optics, University Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - T Teraji
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - J Isoya
- Research Center for Knowledge Communities, University of Tsukuba, 1-2 Kasuga, Tsukuba, Ibaraki 305-8550, Japan
| | - A S Zibrov
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
| | - F Jelezko
- Institute for Quantum Optics, University Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany
| | - M D Lukin
- Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA
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188
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Derntl C, Schneider M, Schalko J, Bittner A, Schmiedmayer J, Schmid U, Trupke M. Arrays of open, independently tunable microcavities. OPTICS EXPRESS 2014; 22:22111-22120. [PMID: 25321586 DOI: 10.1364/oe.22.022111] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Optical cavities are of central importance in numerous areas of physics, including precision measurement, cavity optomechanics and cavity quantum electrodynamics. The miniaturisation and scaling to large numbers of sites is of interest for many of these applications, in particular for quantum computation and simulation. Here we present the first scaled microcavity system which enables the creation of large numbers of highly uniform, tunable light-matter interfaces using ions, neutral atoms or solid-state qubits. The microcavities are created by means of silicon micro-fabrication, are coupled directly to optical fibres and can be independently tuned to the chosen frequency, paving the way for arbitrarily large networks of optical microcavities.
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189
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Liu GQ, Jiang QQ, Chang YC, Liu DQ, Li WX, Gu CZ, Po HC, Zhang WX, Zhao N, Pan XY. Protection of centre spin coherence by dynamic nuclear spin polarization in diamond. NANOSCALE 2014; 6:10134-10139. [PMID: 25042514 DOI: 10.1039/c4nr02007c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We experimentally investigate the protection of electron spin coherence of a nitrogen-vacancy (NV) centre in diamond by dynamic nuclear spin polarization (DNP). The electron spin decoherence of an NV centre is caused by the magnetic field fluctuation of the (13)C nuclear spin bath, which contributes large thermal fluctuation to the centre electron spin when it is in an equilibrium state at room temperature. To address this issue, we continuously transfer the angular momentum from electron spin to nuclear spins, and pump the nuclear spin bath to a polarized state under the Hartmann-Hahn condition. The bath polarization effect is verified by the observation of prolongation of the electron spin coherence time (T). Optimal conditions for the DNP process, including the pumping pulse duration and repeat numbers, are proposed by numerical simulation and confirmed by experiment. We also studied the depolarization effect of laser pulses. Our results provide a new route for quantum information processing and quantum simulation using the polarized nuclear spin bath.
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Affiliation(s)
- Gang-Qin Liu
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
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190
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Bassett LC, Heremans FJ, Christle DJ, Yale CG, Burkard G, Buckley BB, Awschalom DD. Ultrafast optical control of orbital and spin dynamics in a solid-state defect. Science 2014; 345:1333-7. [PMID: 25123482 DOI: 10.1126/science.1255541] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Atom-scale defects in semiconductors are promising building blocks for quantum devices, but our understanding of their material-dependent electronic structure, optical interactions, and dissipation mechanisms is lacking. Using picosecond resonant pulses of light, we study the coherent orbital and spin dynamics of a single nitrogen-vacancy center in diamond over time scales spanning six orders of magnitude. We develop a time-domain quantum tomography technique to precisely map the defect's excited-state Hamiltonian and exploit the excited-state dynamics to control its ground-state spin with optical pulses alone. These techniques generalize to other optically addressable nanoscale spin systems and serve as powerful tools to characterize and control spin qubits for future applications in quantum technology.
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Affiliation(s)
- Lee C Bassett
- Center for Spintronics and Quantum Computation, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - F Joseph Heremans
- Center for Spintronics and Quantum Computation, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - David J Christle
- Center for Spintronics and Quantum Computation, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Christopher G Yale
- Center for Spintronics and Quantum Computation, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA
| | - Guido Burkard
- Department of Physics, University of Konstanz, D-78457 Konstanz, Germany
| | - Bob B Buckley
- Center for Spintronics and Quantum Computation, University of California, Santa Barbara, Santa Barbara, CA 93106, USA
| | - David D Awschalom
- Center for Spintronics and Quantum Computation, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. Institute for Molecular Engineering, University of Chicago, Chicago, IL 60637, USA.
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191
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Collins RJ, Donaldson RJ, Dunjko V, Wallden P, Clarke PJ, Andersson E, Jeffers J, Buller GS. Realization of quantum digital signatures without the requirement of quantum memory. PHYSICAL REVIEW LETTERS 2014; 113:040502. [PMID: 25105603 DOI: 10.1103/physrevlett.113.040502] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Indexed: 06/03/2023]
Abstract
Digital signatures are widely used to provide security for electronic communications, for example, in financial transactions and electronic mail. Currently used classical digital signature schemes, however, only offer security relying on unproven computational assumptions. In contrast, quantum digital signatures offer information-theoretic security based on laws of quantum mechanics. Here, security against forging relies on the impossibility of perfectly distinguishing between nonorthogonal quantum states. A serious drawback of previous quantum digital signature schemes is that they require long-term quantum memory, making them impractical at present. We present the first realization of a scheme that does not need quantum memory and which also uses only standard linear optical components and photodetectors. In our realization, the recipients measure the distributed quantum signature states using a new type of quantum measurement, quantum state elimination. This significantly advances quantum digital signatures as a quantum technology with potential for real applications.
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Affiliation(s)
- Robert J Collins
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, David Brewster Building, Edinburgh EH14 4AS, United Kingdom
| | - Ross J Donaldson
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, David Brewster Building, Edinburgh EH14 4AS, United Kingdom
| | - Vedran Dunjko
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, David Brewster Building, Edinburgh EH14 4AS, United Kingdom and School of Informatics, Informatics Forum, University of Edinburgh, 10 Crichton Street, Edinburgh EH8 9AB, United Kingdom and Laboratory of Evolutionary Genetics, Division of Molecular Biology, Ruđer Bošković Institute, Bijenička Cesta 54, 10000 Zagreb, Croatia
| | - Petros Wallden
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, David Brewster Building, Edinburgh EH14 4AS, United Kingdom
| | - Patrick J Clarke
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, David Brewster Building, Edinburgh EH14 4AS, United Kingdom
| | - Erika Andersson
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, David Brewster Building, Edinburgh EH14 4AS, United Kingdom
| | - John Jeffers
- SUPA, Department of Physics, University of Strathclyde, John Anderson Building, 107 Rottenrow, Glasgow G4 0NG, United Kingdom
| | - Gerald S Buller
- SUPA, Institute of Photonics and Quantum Sciences, School of Engineering and Physical Sciences, Heriot-Watt University, David Brewster Building, Edinburgh EH14 4AS, United Kingdom
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192
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Sangtawesin S, Brundage TO, Petta JR. Fast room-temperature phase gate on a single nuclear spin in diamond. PHYSICAL REVIEW LETTERS 2014; 113:020506. [PMID: 25062156 DOI: 10.1103/physrevlett.113.020506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Indexed: 06/03/2023]
Abstract
Nuclear spins support long lived quantum coherence due to weak coupling to the environment, but are difficult to rapidly control using nuclear magnetic resonance as a result of the small nuclear magnetic moment. We demonstrate a fast ∼500 ns nuclear spin phase gate on a (14)N nuclear spin qubit intrinsic to a nitrogen-vacancy center in diamond. The phase gate is enabled by the hyperfine interaction and off-resonance driving of electron spin transitions. Repeated applications of the phase gate bang-bang decouple the nuclear spin from the environment, locking the spin state for up to ∼140 μs.
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Affiliation(s)
- S Sangtawesin
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - T O Brundage
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
| | - J R Petta
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
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193
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Thiele S, Balestro F, Ballou R, Klyatskaya S, Ruben M, Wernsdorfer W. Electrically driven nuclear spin resonance in single-molecule magnets. Science 2014; 344:1135-8. [PMID: 24904159 DOI: 10.1126/science.1249802] [Citation(s) in RCA: 498] [Impact Index Per Article: 49.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Recent advances in addressing isolated nuclear spins have opened up a path toward using nuclear-spin-based quantum bits. Local magnetic fields are normally used to coherently manipulate the state of the nuclear spin; however, electrical manipulation would allow for fast switching and spatially confined spin control. Here, we propose and demonstrate coherent single nuclear spin manipulation using electric fields only. Because there is no direct coupling between the spin and the electric field, we make use of the hyperfine Stark effect as a magnetic field transducer at the atomic level. This quantum-mechanical process is present in all nuclear spin systems, such as phosphorus or bismuth atoms in silicon, and offers a general route toward the electrical control of nuclear-spin-based devices.
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Affiliation(s)
- Stefan Thiele
- CNRS, Inst NEEL, F-38042 Grenoble, France. Université Grenoble Alpes, Inst NEEL, F-38042 Grenoble, France
| | - Franck Balestro
- CNRS, Inst NEEL, F-38042 Grenoble, France. Université Grenoble Alpes, Inst NEEL, F-38042 Grenoble, France. Institut Universitaire de France, 103 boulevard Saint-Michel, 75005 Paris, France
| | - Rafik Ballou
- CNRS, Inst NEEL, F-38042 Grenoble, France. Université Grenoble Alpes, Inst NEEL, F-38042 Grenoble, France
| | - Svetlana Klyatskaya
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany
| | - Mario Ruben
- Institute of Nanotechnology, Karlsruhe Institute of Technology, 76344 Eggenstein-Leopoldshafen, Germany. Institut de Physique et de Chimie des Materiaux de Strasbourg, CNRS, 67034 Strasbourg, France
| | - Wolfgang Wernsdorfer
- CNRS, Inst NEEL, F-38042 Grenoble, France. Université Grenoble Alpes, Inst NEEL, F-38042 Grenoble, France.
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194
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Türschmann P, Colell J, Theis T, Blümich B, Appelt S. Analysis of parahydrogen polarized spin system in low magnetic fields. Phys Chem Chem Phys 2014; 16:15411-21. [PMID: 24947652 DOI: 10.1039/c4cp01807a] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Nuclear magnetic resonance (NMR) spectra of spin systems polarized either thermally or by parahydrogen exhibit strikingly different field dependencies. Thermally polarized spin systems show the well-known roof effect, observed when reducing magnetic field strengths which precludes the independent determination of chemical shift differences and J-coupling constants at low-fields. Quantum mechanical analysis of the NMR spectra with respect to polarization method, pulsed state preparation, and transition probabilities reveals that spectra of parahydrogen polarized systems feature an "inverse roof effect" in the regime where the chemical shift difference δν is smaller than J. This inverse roof effect allows for the extraction of both J-coupling and chemical shift information down to very low fields. Based on a two-spin system, the observed non-linear magnetic field dependence of the splitting of spectral lines is predicted. We develop a general solution for the steady state density matrix of a parahydrogen polarized three-spin system including a heteronucleus which allows explaining experimentally observed (1)H spectra. The analysis of three-spin density matrix illustrates two pathways for an efficient polarization transfer from parahydrogen to (13)C nuclei. Examination of the experimental data facilitates the extraction of all relevant NMR parameters using single-scan, high-resolution (1)H and (13)C NMR spectroscopy at low fields at a fraction of the cost associated with cryogenically cooled high-field NMR spectrometers.
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Affiliation(s)
- P Türschmann
- Institut für Technische und Markomolekulare Chemie, RWTH Aachen University, 52056 Aachen, Germany.
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195
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Dehollain JP, Muhonen JT, Tan KY, Saraiva A, Jamieson DN, Dzurak AS, Morello A. Single-shot readout and relaxation of singlet and triplet states in exchange-coupled 31P electron spins in silicon. PHYSICAL REVIEW LETTERS 2014; 112:236801. [PMID: 24972221 DOI: 10.1103/physrevlett.112.236801] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Indexed: 06/03/2023]
Abstract
We present the experimental observation of a large exchange coupling J ≈ 300 μeV between two (31)P electron spin qubits in silicon. The singlet and triplet states of the coupled spins are monitored in real time by a single-electron transistor, which detects ionization from tunnel-rate-dependent processes in the coupled spin system, yielding single-shot readout fidelities above 95%. The triplet to singlet relaxation time T(1) ≈ 4 ms at zero magnetic field agrees with the theoretical prediction for J-coupled 31P dimers in silicon. The time evolution of the two-electron state populations gives further insight into the valley-orbit eigenstates of the donor dimer, valley selection rules and relaxation rates, and the role of hyperfine interactions. These results pave the way to the realization of two-qubit quantum logic gates with spins in silicon and highlight the necessity to adopt gating schemes compatible with weak J-coupling strengths.
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Affiliation(s)
- Juan P Dehollain
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Juha T Muhonen
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Kuan Y Tan
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Andre Saraiva
- Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21941-972 Rio de Janeiro, Brazil and University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - David N Jamieson
- Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Andrew S Dzurak
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
| | - Andrea Morello
- Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Australia, Sydney, New South Wales 2052, Australia
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196
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Thomas N, Barbour RJ, Song Y, Lee ML, Fu KMC. Waveguide-integrated single-crystalline GaP resonators on diamond. OPTICS EXPRESS 2014; 22:13555-13564. [PMID: 24921549 DOI: 10.1364/oe.22.013555] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Large-scale entanglement of nitrogen-vacancy (NV) centers in diamond will require integration of NV centers with optical networks. Toward this goal, we present the fabrication of single-crystalline gallium phosphide (GaP) resonator-waveguide coupled structures on diamond. We demonstrate coupling between 1 μm diameter GaP disk resonators and waveguides with a loaded Q factor of 3,800, and evaluate their potential for efficient photon collection if integrated with single photon emitters. This work opens a path toward scalable NV entanglement in the hybrid GaP/diamond platform, with the potential to integrate on-chip photon collection, switching, and detection for applications in quantum information processing.
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197
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Pfaff W, Hensen BJ, Bernien H, van Dam SB, Blok MS, Taminiau TH, Tiggelman MJ, Schouten RN, Markham M, Twitchen DJ, Hanson R. Quantum information. Unconditional quantum teleportation between distant solid-state quantum bits. Science 2014; 345:532-5. [PMID: 25082696 DOI: 10.1126/science.1253512] [Citation(s) in RCA: 111] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Realizing robust quantum information transfer between long-lived qubit registers is a key challenge for quantum information science and technology. Here we demonstrate unconditional teleportation of arbitrary quantum states between diamond spin qubits separated by 3 meters. We prepare the teleporter through photon-mediated heralded entanglement between two distant electron spins and subsequently encode the source qubit in a single nuclear spin. By realizing a fully deterministic Bell-state measurement combined with real-time feed-forward, quantum teleportation is achieved upon each attempt with an average state fidelity exceeding the classical limit. These results establish diamond spin qubits as a prime candidate for the realization of quantum networks for quantum communication and network-based quantum computing.
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Affiliation(s)
- W Pfaff
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - B J Hensen
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - H Bernien
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - S B van Dam
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - M S Blok
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - T H Taminiau
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - M J Tiggelman
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - R N Schouten
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands
| | - M Markham
- Element Six, Ltd., Kings Ride Park, Ascot, Berkshire SL5 8BP, UK
| | - D J Twitchen
- Element Six, Ltd., Kings Ride Park, Ascot, Berkshire SL5 8BP, UK
| | - R Hanson
- Kavli Institute of Nanoscience Delft, Delft University of Technology, Post Office Box 5046, 2600 GA Delft, Netherlands.
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198
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Kessler EM, Lovchinsky I, Sushkov AO, Lukin MD. Quantum error correction for metrology. PHYSICAL REVIEW LETTERS 2014; 112:150802. [PMID: 24785020 DOI: 10.1103/physrevlett.112.150802] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Indexed: 06/03/2023]
Abstract
We propose and analyze a new approach based on quantum error correction (QEC) to improve quantum metrology in the presence of noise. We identify the conditions under which QEC allows one to improve the signal-to-noise ratio in quantum-limited measurements, and we demonstrate that it enables, in certain situations, Heisenberg-limited sensitivity. We discuss specific applications to nanoscale sensing using nitrogen-vacancy centers in diamond in which QEC can significantly improve the measurement sensitivity and bandwidth under realistic experimental conditions.
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Affiliation(s)
- E M Kessler
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA and ITAMP, Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts 02138, USA
| | - I Lovchinsky
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA
| | - A O Sushkov
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA and Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA
| | - M D Lukin
- Physics Department, Harvard University, Cambridge, Massachusetts 02138, USA
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199
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Golter DA, Wang H. Optically driven Rabi oscillations and adiabatic passage of single electron spins in diamond. PHYSICAL REVIEW LETTERS 2014; 112:116403. [PMID: 24702393 DOI: 10.1103/physrevlett.112.116403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Indexed: 06/03/2023]
Abstract
Rabi oscillations and adiabatic passage of single electron spins in a diamond nitrogen vacancy center are demonstrated with two Raman-resonant optical pulses that are detuned from the respective dipole optical transitions. We show that the optical spin control is nuclear-spin selective and can be robust against rapid decoherence, including radiative decay and spectral diffusion, of the underlying optical transitions. A direct comparison between the Rabi oscillation and the adiabatic passage, along with a detailed theoretical analysis, provides significant physical insights into the connections and differences between these coherent spin processes and also elucidates the role of spectral diffusion in these processes. The optically driven coherent spin processes enable the use of nitrogen vacancy excited states to mediate coherent spin-phonon coupling, opening the door to combining optical control of both spin and mechanical degrees of freedom.
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Affiliation(s)
- D Andrew Golter
- Department of Physics and Oregon Center for Optics, University of Oregon, Eugene, Oregon 97403, USA
| | - Hailin Wang
- Department of Physics and Oregon Center for Optics, University of Oregon, Eugene, Oregon 97403, USA
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200
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Erven C, Ng N, Gigov N, Laflamme R, Wehner S, Weihs G. An experimental implementation of oblivious transfer in the noisy storage model. Nat Commun 2014; 5:3418. [PMID: 24618984 DOI: 10.1038/ncomms4418] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Accepted: 02/10/2014] [Indexed: 11/09/2022] Open
Abstract
Cryptography's importance in our everyday lives continues to grow in our increasingly digital world. Oblivious transfer has long been a fundamental and important cryptographic primitive, as it is known that general two-party cryptographic tasks can be built from this basic building block. Here we show the experimental implementation of a 1-2 random oblivious transfer protocol by performing measurements on polarization-entangled photon pairs in a modified entangled quantum key distribution system, followed by all of the necessary classical postprocessing including one-way error correction. We successfully exchange a 1,366 bit random oblivious transfer string in ~3 min and include a full security analysis under the noisy storage model, accounting for all experimental error rates and finite size effects. This demonstrates the feasibility of using today's quantum technologies to implement secure two-party protocols.
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Affiliation(s)
- C Erven
- 1] Institute for Quantum Computing and Department of Physics & Astronomy, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 [2] Centre for Quantum Photonics, H. H. Wills Physics Laboratory & Department of Electrical and Electronic Engineering, University of Bristol, Merchant Venturers Building, Woodland Road, Bristol BS8 1UB, UK
| | - N Ng
- Center for Quantum Technologies, National University of Singapore, 2 Science Drive 3, Singapore 117543
| | - N Gigov
- Institute for Quantum Computing and Department of Physics & Astronomy, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1
| | - R Laflamme
- 1] Institute for Quantum Computing and Department of Physics & Astronomy, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 [2] Perimeter Institute, 31 Caroline Street North, Waterloo, Ontario, Canada N2L 2Y5
| | - S Wehner
- 1] Center for Quantum Technologies, National University of Singapore, 2 Science Drive 3, Singapore 117543 [2] School of Computing, National University of Singapore, 13 Computing Drive, Singapore 117417
| | - G Weihs
- 1] Institute for Quantum Computing and Department of Physics & Astronomy, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1 [2] Institut für Experimentalphysik, Universität Innsbruck, Technikerstrasse 25, 6020 Innsbruck, Austria
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