101
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Eddins AW, Beedle CC, Hendrickson DN, Friedman JR. Collective coupling of a macroscopic number of single-molecule magnets with a microwave cavity mode. PHYSICAL REVIEW LETTERS 2014; 112:120501. [PMID: 24724636 DOI: 10.1103/physrevlett.112.120501] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Indexed: 06/03/2023]
Abstract
We report the observation of strong coupling of a macroscopic ensemble of ∼1016 Fe8 molecular nanomagnets to the resonant mode of a microwave cavity. We use millimeter-wave spectroscopy to measure the splitting of the system's resonant frequency induced by the coupling between the spins and the cavity mode. The magnitude of this splitting is found to scale with √N, where N is the number of collectively coupled spins. We control N by changing the system's temperature and, thereby, the populations of the relevant spin energy levels. Strong coupling is observed for two distinct transitions between spin energy states. Our results indicate that at low temperatures nearly all of the spins in the sample couple with the cavity's resonant mode even though there is substantial inhomogeneous broadening of the Fe8 spin resonances.
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Affiliation(s)
- A W Eddins
- Department of Physics, Amherst College, Amherst, Massachusetts 01002-5000, USA
| | - C C Beedle
- Department of Chemistry & Biochemistry, University of California at San Diego, La Jolla, California 92093, USA
| | - D N Hendrickson
- Department of Chemistry & Biochemistry, University of California at San Diego, La Jolla, California 92093, USA
| | - Jonathan R Friedman
- Department of Physics, Amherst College, Amherst, Massachusetts 01002-5000, USA
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102
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High-fidelity spin entanglement using optimal control. Nat Commun 2014; 5:3371. [DOI: 10.1038/ncomms4371] [Citation(s) in RCA: 208] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 02/03/2014] [Indexed: 12/22/2022] Open
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103
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Chanelière T. Strong excitation of emitters in an impedance matched cavity: the area theorem, π-pulse and self-induced transparency. OPTICS EXPRESS 2014; 22:4423-4436. [PMID: 24663765 DOI: 10.1364/oe.22.004423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
I theoretically study the behavior of strong pulses exciting emitters inside a cavity. The ensemble is supposed to be inhomogeneously broadened and the cavity matched finding application in quantum storage of optical or RF photons. My analysis is based on energy and pulse area conservation rules predicting important distortions for specific areas. It is well supported by numerical simulations. I propose a qualitative interpretation in terms of slow-light. The analogy with the free space situation is remarkable.
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104
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Wood CJ, Borneman TW, Cory DG. Cavity cooling of an ensemble spin system. PHYSICAL REVIEW LETTERS 2014; 112:050501. [PMID: 24580576 DOI: 10.1103/physrevlett.112.050501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Indexed: 06/03/2023]
Abstract
We describe how sideband cooling techniques may be applied to large spin ensembles in magnetic resonance. Using the Tavis-Cummings model in the presence of a Rabi drive, we solve a Markovian master equation describing the joint spin-cavity dynamics to derive cooling rates as a function of ensemble size. Our calculations indicate that the coupled angular momentum subspaces of a spin ensemble containing roughly 10(11) electron spins may be polarized in a time many orders of magnitude shorter than the typical thermal relaxation time. The described techniques should permit efficient removal of entropy for spin-based quantum information processors and fast polarization of spin samples. The proposed application of a standard technique in quantum optics to magnetic resonance also serves to reinforce the connection between the two fields, which has recently begun to be explored in further detail due to the development of hybrid designs for manufacturing noise-resilient quantum devices.
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Affiliation(s)
- Christopher J Wood
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - Troy W Borneman
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| | - David G Cory
- Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada
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105
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Quantum Computation with Molecular Nanomagnets: Achievements, Challenges, and New Trends. MOLECULAR NANOMAGNETS AND RELATED PHENOMENA 2014. [DOI: 10.1007/430_2014_145] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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106
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Ohashi K, Rosskopf T, Watanabe H, Loretz M, Tao Y, Hauert R, Tomizawa S, Ishikawa T, Ishi-Hayase J, Shikata S, Degen CL, Itoh KM. Negatively charged nitrogen-vacancy centers in a 5 nm thin 12C diamond film. NANO LETTERS 2013; 13:4733-4738. [PMID: 24020334 DOI: 10.1021/nl402286v] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We report successful introduction of negatively charged nitrogen-vacancy (NV(-)) centers in a 5 nm thin, isotopically enriched ([(12)C] = 99.99%) diamond layer by CVD. The present method allows for the formation of NV(-) in such a thin layer even when the surface is terminated by hydrogen atoms. NV(-) centers are found to have spin coherence times of between T2 ~ 10-100 μs at room temperature. Changing the surface termination to oxygen or fluorine leads to a slight increase in the NV(-) density, but not to any significant change in T2. The minimum detectable magnetic field estimated by this T2 is 3 nT after 100 s of averaging, which would be sufficient for the detection of nuclear magnetic fields exerted by a single proton. We demonstrate the suitability for nanoscale NMR by measuring the fluctuating field from ~10(4) proton nuclei placed on top of the 5 nm diamond film.
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Affiliation(s)
- K Ohashi
- School of Fundamental Science and Technology, Keio University , Yokohama 223-8522, Japan
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107
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Huebl H, Zollitsch CW, Lotze J, Hocke F, Greifenstein M, Marx A, Gross R, Goennenwein STB. High cooperativity in coupled microwave resonator ferrimagnetic insulator hybrids. PHYSICAL REVIEW LETTERS 2013; 111:127003. [PMID: 24093293 DOI: 10.1103/physrevlett.111.127003] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2012] [Indexed: 05/23/2023]
Abstract
We report the observation of strong coupling between the exchange-coupled spins in a gallium-doped yttrium iron garnet and a superconducting coplanar microwave resonator made from Nb. The measured coupling rate of 450 MHz is proportional to the square root of the number of exchange-coupled spins and well exceeds the loss rate of 50 MHz of the spin system. This demonstrates that exchange-coupled systems are suitable for cavity quantum electrodynamics experiments, while allowing high integration densities due to their spin densities of the order of one Bohr magneton per atom. Our results furthermore show, that experiments with multiple exchange-coupled spin systems interacting via a single resonator are within reach.
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Affiliation(s)
- Hans Huebl
- Walther-Meißner-Institut, Bayerische Akademie der Wissenschaften, 85748 Garching, Germany
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108
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Carretta S, Chiesa A, Troiani F, Gerace D, Amoretti G, Santini P. Quantum information processing with hybrid spin-photon qubit encoding. PHYSICAL REVIEW LETTERS 2013; 111:110501. [PMID: 24074061 DOI: 10.1103/physrevlett.111.110501] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Indexed: 06/02/2023]
Abstract
We introduce a scheme to perform quantum information processing that is based on a hybrid spin-photon qubit encoding. The proposed qubits consist of spin ensembles coherently coupled to microwave photons in coplanar waveguide resonators. The quantum gates are performed solely by shifting the resonance frequencies of the resonators on a nanosecond time scale. An additional cavity containing a Cooper-pair box is exploited as an auxiliary degree of freedom to implement two-qubit gates. The generality of the scheme allows its potential implementation with a wide class of spin systems.
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Affiliation(s)
- S Carretta
- Dipartimento di Fisica e Scienze della Terra, Università di Parma, I-43124 Parma, Italy
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109
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Saito S, Zhu X, Amsüss R, Matsuzaki Y, Kakuyanagi K, Shimo-Oka T, Mizuochi N, Nemoto K, Munro WJ, Semba K. Towards realizing a quantum memory for a superconducting qubit: storage and retrieval of quantum states. PHYSICAL REVIEW LETTERS 2013; 111:107008. [PMID: 25166702 DOI: 10.1103/physrevlett.111.107008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2013] [Indexed: 06/03/2023]
Abstract
We have built a hybrid system composed of a superconducting flux qubit (the processor) and an ensemble of nitrogen-vacancy centers in diamond (the memory) that can be directly coupled to one another, and demonstrated how information can be transferred from the flux qubit to the memory, stored, and subsequently retrieved. We have established the coherence properties of the memory and succeeded in creating an entangled state between the processor and memory, demonstrating how the entangled state's coherence is preserved. Our results are a significant step towards using an electron spin ensemble as a quantum memory for superconducting qubits.
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Affiliation(s)
- Shiro Saito
- 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
| | - Robert Amsüss
- NTT Basic Research Laboratories, NTT Corporation, 3-1, Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan and Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, 1020 Vienna, Austria
| | - Yuichiro Matsuzaki
- 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
| | - Takaaki Shimo-Oka
- Graduate School of Engineering Science, Osaka University, 1-3 Machikane-yama, Toyonaka, Osaka 560-8531, Japan
| | - Norikazu Mizuochi
- Graduate School of Engineering Science, Osaka University, 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
| | - William J Munro
- NTT Basic Research Laboratories, NTT Corporation, 3-1, Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan
| | - Kouichi Semba
- NTT Basic Research Laboratories, NTT Corporation, 3-1, Morinosato-Wakamiya, Atsugi, Kanagawa 243-0198, Japan and National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo 101-8430, Japan
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110
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Lee SY, Widmann M, Rendler T, Doherty MW, Babinec TM, Yang S, Eyer M, Siyushev P, Hausmann BJM, Loncar M, Bodrog Z, Gali A, Manson NB, Fedder H, Wrachtrup J. Readout and control of a single nuclear spin with a metastable electron spin ancilla. NATURE NANOTECHNOLOGY 2013; 8:487-92. [PMID: 23793305 DOI: 10.1038/nnano.2013.104] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2013] [Accepted: 05/07/2013] [Indexed: 05/27/2023]
Abstract
Electron and nuclear spins associated with point defects in insulators are promising systems for solid-state quantum technology. The electron spin is usually used for readout and addressing, and nuclear spins are used as exquisite quantum bits and memory systems. With these systems, single-shot readout of single nuclear spins as well as entanglement, aided by the electron spin, have been shown. Although the electron spin in this example is essential for readout, it usually limits the nuclear spin coherence, leading to a quest for defects with spin-free ground states. Here, we isolate a hitherto unidentified defect in diamond and use it at room temperature to demonstrate optical spin polarization and readout with exceptionally high contrast (up to 45%), coherent manipulation of an individual excited triplet state spin, and coherent nuclear spin manipulation using the triplet electron spin as a metastable ancilla. We demonstrate nuclear magnetic resonance and Rabi oscillations of the uncoupled nuclear spin in the spin-free electronic ground state. Our study demonstrates that nuclei coupled to single metastable electron spins are useful quantum systems with long memory times, in spite of electronic relaxation processes.
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Affiliation(s)
- Sang-Yun Lee
- Physikalisches Institut and Research Center SCOPE, University Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart, Germany
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111
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Julsgaard B, Grezes C, Bertet P, Mølmer K. Quantum memory for microwave photons in an inhomogeneously broadened spin ensemble. PHYSICAL REVIEW LETTERS 2013; 110:250503. [PMID: 23829721 DOI: 10.1103/physrevlett.110.250503] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Indexed: 06/02/2023]
Abstract
We propose a multimode quantum memory protocol able to store the quantum state of the field in a microwave resonator into an ensemble of electronic spins. The stored information is protected against inhomogeneous broadening of the spin ensemble by spin-echo techniques resulting in memory times orders of magnitude longer than previously achieved. By calculating the evolution of the first and second moments of the spin-cavity system variables for current experimental parameters, we show that a memory based on nitrogen vacancy center spins in diamond can store a qubit encoded on the |0> and |1> Fock states of the field with 80% fidelity and outperform classical memory strategies for storage times ≤69 μs.
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Affiliation(s)
- Brian Julsgaard
- Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark.
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112
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Boero G, Gualco G, Lisowski R, Anders J, Suter D, Brugger J. Room temperature strong coupling between a microwave oscillator and an ensemble of electron spins. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 231:133-140. [PMID: 23644353 DOI: 10.1016/j.jmr.2013.04.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/05/2013] [Accepted: 04/06/2013] [Indexed: 06/02/2023]
Abstract
We demonstrate theoretically and experimentally the possibility to achieve the strong coupling regime at room temperature with a microwave electronic oscillator coupled with an ensemble of electron spins. The coupled system shows bistable behaviour, with a broad hysteresis and sharp transitions. The coupling strength and the hysteresis width can be adjusted through the number of spins in the ensemble, the temperature, and the microwave field strength.
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Affiliation(s)
- G Boero
- Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne, Switzerland.
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113
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114
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Benningshof OWB, Mohebbi HR, Taminiau IAJ, Miao GX, Cory DG. Superconducting microstrip resonator for pulsed ESR of thin films. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2013; 230:84-87. [PMID: 23454577 DOI: 10.1016/j.jmr.2013.01.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Revised: 01/24/2013] [Accepted: 01/25/2013] [Indexed: 06/01/2023]
Abstract
This article describes a superconducting microstrip resonator operating at 9.5 GHz (X-band) that is specially designed for pulsed ESR on thin films. A novel configuration consisting of an array of half-wave length microstrip transmission lines generates a uniform magnetic field over a 2-D region of 100×1000 μm(2) with field homogeneity better than 5×10(-2). Using the device, we demonstrate strong coupling of the resonator to an electron spin ensemble and pulsed ESR on Si:P.
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115
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Probst S, Rotzinger H, Wünsch S, Jung P, Jerger M, Siegel M, Ustinov AV, Bushev PA. Anisotropic rare-earth spin ensemble strongly coupled to a superconducting resonator. PHYSICAL REVIEW LETTERS 2013; 110:157001. [PMID: 25167299 DOI: 10.1103/physrevlett.110.157001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Indexed: 06/03/2023]
Abstract
Interfacing photonic and solid-state qubits within a hybrid quantum architecture offers a promising route towards large scale distributed quantum computing. Ideal candidates for coherent qubit interconversion are optically active spins, magnetically coupled to a superconducting resonator. We report on an on-chip cavity QED experiment with magnetically anisotropic Er(3+)∶Y2SiO5 crystals and demonstrate collective strong coupling of rare-earth spins to a lumped element resonator. Moreover, the electron spin resonance and relaxation dynamics of the erbium spins are detected via direct microwave absorption, without the aid of a cavity.
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Affiliation(s)
- S Probst
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
| | - H Rotzinger
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
| | - S Wünsch
- Institut für Mikro- und Nanoelektronische Systeme, Karlsruhe Institute of Technology, D-76189 Karlsruhe, Germany
| | - P Jung
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
| | - M Jerger
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
| | - M Siegel
- Institut für Mikro- und Nanoelektronische Systeme, Karlsruhe Institute of Technology, D-76189 Karlsruhe, Germany
| | - A V Ustinov
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
| | - P A Bushev
- Physikalisches Institut, Karlsruhe Institute of Technology, D-76128 Karlsruhe, Germany
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116
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Desvaux H. Non-linear liquid-state NMR. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2013; 70:50-71. [PMID: 23540576 DOI: 10.1016/j.pnmrs.2012.11.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2012] [Accepted: 10/31/2012] [Indexed: 06/02/2023]
Affiliation(s)
- Hervé Desvaux
- CEA, IRAMIS, SIS2M, UMR CEA/CNRS 3299, Laboratoire Structure et Dynamique par Résonance Magnétique, CEA/Saclay, Gif-sur-Yvette, France.
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117
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Fang K, Acosta VM, Santori C, Huang Z, Itoh KM, Watanabe H, Shikata S, Beausoleil RG. High-sensitivity magnetometry based on quantum beats in diamond nitrogen-vacancy centers. PHYSICAL REVIEW LETTERS 2013; 110:130802. [PMID: 23581305 DOI: 10.1103/physrevlett.110.130802] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Indexed: 06/02/2023]
Abstract
We demonstrate an absolute magnetometer based on quantum beats in the ground state of nitrogen-vacancy centers in diamond. We show that, by eliminating the dependence of spin evolution on the zero-field splitting D, the magnetometer is immune to temperature fluctuation and strain inhomogeneity. We apply this technique to measure low-frequency magnetic field noise by using a single nitrogen-vacancy center located within 500 nm of the surface of an isotopically pure (99.99% 12C) diamond. The photon-shot-noise limited sensitivity achieves 38 nT/sqrt[Hz] for 4.45 s acquisition time, a factor of sqrt[2] better than the implementation which uses only two spin levels. For long acquisition times (>10 s), we realize up to a factor of 15 improvement in magnetic sensitivity, which demonstrates the robustness of our technique against thermal drifts. Applying our technique to nitrogen-vacancy center ensembles, we eliminate dephasing from longitudinal strain inhomogeneity, resulting in a factor of 2.3 improvement in sensitivity.
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Affiliation(s)
- Kejie Fang
- Department of Physics, Stanford University, Stanford, California 94305, USA
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118
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Yin Y, Chen Y, Sank D, O'Malley PJJ, White TC, Barends R, Kelly J, Lucero E, Mariantoni M, Megrant A, Neill C, Vainsencher A, Wenner J, Korotkov AN, Cleland AN, Martinis JM. Catch and release of microwave photon states. PHYSICAL REVIEW LETTERS 2013; 110:107001. [PMID: 23521281 DOI: 10.1103/physrevlett.110.107001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Indexed: 06/01/2023]
Abstract
We demonstrate a superconducting resonator with variable coupling to a measurement transmission line. The resonator coupling can be adjusted through zero to a photon emission rate 1000 times the intrinsic resonator decay rate. We demonstrate the catch and release of photons in the resonator, as well as control of nonclassical Fock states. We also demonstrate the dynamical control of the release waveform of photons from the resonator, a key functionality that will enable high-fidelity quantum state transfer between distant resonators or qubits.
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Affiliation(s)
- Yi Yin
- Department of Physics, University of California, Santa Barbara, California 93106, USA.
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119
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Ranjan V, de Lange G, Schutjens R, Debelhoir T, Groen JP, Szombati D, Thoen DJ, Klapwijk TM, Hanson R, DiCarlo L. Probing dynamics of an electron-spin ensemble via a superconducting resonator. PHYSICAL REVIEW LETTERS 2013; 110:067004. [PMID: 23432295 DOI: 10.1103/physrevlett.110.067004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Indexed: 06/01/2023]
Abstract
We study spin relaxation and diffusion in an electron-spin ensemble of nitrogen impurities in diamond at low temperature (0.25-1.2 K) and polarizing magnetic field (80-300 mT). Measurements exploit field-controlled coupling of the ensemble to two modes of a transmission-line resonator. The observed temperature-independent spin relaxation time indicates that spin outdiffusion across the mode volume dominates over spin-lattice relaxation. Depolarization of one hyperfine-split subensemble by pumping of another indicates fast cross relaxation, with implications for the use of subensembles as independent quantum memories.
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Affiliation(s)
- V Ranjan
- Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 5046, 2600 GA Delft, The Netherlands
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120
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Malissa H, Schuster DI, Tyryshkin AM, Houck AA, Lyon SA. Superconducting coplanar waveguide resonators for low temperature pulsed electron spin resonance spectroscopy. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2013; 84:025116. [PMID: 23464260 DOI: 10.1063/1.4792205] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We discuss the design and implementation of thin film superconducting coplanar waveguide micro-resonators for pulsed electron spin resonance experiments. The performance of the resonators with P doped Si epilayer samples is compared to waveguide resonators under equivalent conditions. The high achievable filling factor even for small sized samples and the relatively high Q-factor result in a sensitivity of 4.5 × 10(8) spins per shot, which is superior to that of conventional waveguide resonators, in particular to spins close to the sample surface. The peak microwave power is on the order of a few milliwatts, which is compatible with measurements at ultra-low temperatures. We also discuss the effect of the nonuniform microwave magnetic field on the Hahn echo power dependence.
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Affiliation(s)
- H Malissa
- Department of Electrical Engineering, Princeton University, Olden Street, Princeton, New Jersey 08544, USA
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121
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Photon-mediated interaction between distant quantum dot circuits. Nat Commun 2013; 4:1400. [DOI: 10.1038/ncomms2407] [Citation(s) in RCA: 87] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Accepted: 12/20/2012] [Indexed: 11/08/2022] Open
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122
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George RE, Edwards JP, Ardavan A. Coherent spin control by electrical manipulation of the magnetic anisotropy. PHYSICAL REVIEW LETTERS 2013; 110:027601. [PMID: 23383938 DOI: 10.1103/physrevlett.110.027601] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Indexed: 06/01/2023]
Abstract
High-spin paramagnetic manganese defects in polar piezoelectric zinc oxide exhibit a simple, almost axial anisotropy and phase coherence times of the order of a millisecond at low temperatures. The anisotropy energy is tunable using an externally applied electric field. This can be used to control electrically the phase of spin superpositions and to drive spin transitions with resonant microwave electric fields.
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Affiliation(s)
- Richard E George
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, United Kingdom
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123
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Tsukanov AV. NV centers in diamond. Part III: Quantum algorithms, scaling, and hybrid systems. ACTA ACUST UNITED AC 2013. [DOI: 10.1134/s1063739713010058] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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124
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Leung PM, Sanders BC. Coherent control of microwave pulse storage in superconducting circuits. PHYSICAL REVIEW LETTERS 2012; 109:253603. [PMID: 23368461 DOI: 10.1103/physrevlett.109.253603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Indexed: 06/01/2023]
Abstract
Coherent pulse control for quantum memory is viable in the optical domain but nascent in microwave quantum circuits. We show how to realize coherent storage and on-demand pulse retrieval entirely within a superconducting circuit by exploiting and extending existing electromagnetically induced transparency technology in superconducting quantum circuits. Our scheme employs a linear array of superconducting artificial atoms coupled to a microwave transmission line.
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Affiliation(s)
- Patrick M Leung
- Institute for Quantum Information Science, University of Calgary, Alberta T2N 1N4, Canada.
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125
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Simmons S, Wu H, Morton JJL. Controlling and exploiting phases in multi-spin systems using electron spin resonance and nuclear magnetic resonance. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2012; 370:4794-4809. [PMID: 22946041 DOI: 10.1098/rsta.2011.0354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The phase of a superposition state is a quintessential characteristic that differentiates a quantum bit of information from a classical one. This phase can be manipulated dynamically or geometrically, and can be exploited to sensitively estimate Hamiltonian parameters, perform faithful quantum state tomography and encode quantum information into multiple modes of an ensemble. Here we discuss the methods that we have employed to manipulate and exploit the phase information of single-, two-, multi-qubit and multi-mode spin systems.
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Affiliation(s)
- Stephanie Simmons
- Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH, UK
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126
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Barzanjeh S, Abdi M, Milburn GJ, Tombesi P, Vitali D. Reversible optical-to-microwave quantum interface. PHYSICAL REVIEW LETTERS 2012; 109:130503. [PMID: 23030075 DOI: 10.1103/physrevlett.109.130503] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Indexed: 06/01/2023]
Abstract
We describe a reversible quantum interface between an optical and a microwave field using a hybrid device based on their common interaction with a micromechanical resonator in a superconducting circuit. We show that, by employing state-of-the-art optoelectromechanical devices, one can realize an effective source of (bright) two-mode squeezing with an optical idler (signal) and a microwave signal, which can be used for high-fidelity transfer of quantum states between optical and microwave fields by means of continuous variable teleportation.
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Affiliation(s)
- Sh Barzanjeh
- School of Science and Technology, Physics Division, University of Camerino, Camerino, Macerata 62032, Italy
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127
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ROY-GUAY DAVID, PIORO-LADRIÈRE MICHEL, MORRIS DENIS, TALLAIRE ALEXANDRE, ACHARD JOCELYN, DROUIN DOMINIQUE. CATHODOLUMINESCENCE AND PHOTOLUMINESCENCE OF NV CENTERS. INTERNATIONAL JOURNAL OF NANOSCIENCE 2012. [DOI: 10.1142/s0219581x12400169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Nitrogen-vacancy (NV) centers in diamond are a promising candidate as a solid state qubit memory for quantum information as they possess very long coherence times even at room temperature. Furthermore, NV centers are very sensitive to their electromagnetic environment and are addressable in the GHz frequency range. Here we review our progress towards the detection of single NV centers for the implementation of fast on demand coupling between NV centers and GHz electromagnetic fields. Precisely, we present efforts towards mapping NV centers with a cathodoluminescence setup. Developing such capability is important for patterning local one-qubit gates for the application of high amplitude electromagnetic fields as a tuning parameter.
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Affiliation(s)
- DAVID ROY-GUAY
- Département de Physique, Université de Sherbrooke, 2500 Boul. Université, Sherbrooke, QC, J1K 2R1, Canada
| | - MICHEL PIORO-LADRIÈRE
- Département de Physique, Université de Sherbrooke, 2500 Boul. Université, Sherbrooke, QC, J1K 2R1, Canada
| | - DENIS MORRIS
- Département de Physique, Université de Sherbrooke, 2500 Boul. Université, Sherbrooke, QC, J1K 2R1, Canada
| | - ALEXANDRE TALLAIRE
- LSPM, Université Paris 13, CNRS, 99 avenue Jean-Baptiste Clément, 93430 Villetaneuse, France
| | - JOCELYN ACHARD
- LSPM, Université Paris 13, CNRS, 99 avenue Jean-Baptiste Clément, 93430 Villetaneuse, France
| | - DOMINIQUE DROUIN
- Département de génie électrique et génie informatique, Université de Sherbrooke, 2500 Boul. Université, Sherbrooke, QC, J1K 2R1, Canada
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128
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Martínez-Pérez MJ, Cardona-Serra S, Schlegel C, Moro F, Alonso PJ, Prima-García H, Clemente-Juan JM, Evangelisti M, Gaita-Ariño A, Sesé J, van Slageren J, Coronado E, Luis F. Gd-based single-ion magnets with tunable magnetic anisotropy: molecular design of spin qubits. PHYSICAL REVIEW LETTERS 2012; 108:247213. [PMID: 23004325 DOI: 10.1103/physrevlett.108.247213] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Indexed: 05/14/2023]
Abstract
We report ac susceptibility and continuous wave and pulsed EPR experiments performed on GdW10 and GdW30 polyoxometalate clusters, in which a Gd3+ ion is coordinated to different polyoxometalate moieties. Despite the isotropic character of gadolinium as a free ion, these molecules show slow magnetic relaxation at very low temperatures, characteristic of single molecule magnets. For T≲200 mK, the spin-lattice relaxation becomes dominated by pure quantum tunneling events, with rates that agree quantitatively with those predicted by the Prokof'ev and Stamp model [Phys. Rev. Lett. 80, 5794 (1998)]. The sign of the magnetic anisotropy, the energy level splittings, and the tunneling rates strongly depend on the molecular structure. We argue that GdW30 molecules are also promising spin qubits with a coherence figure of merit Q(M)≳50.
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Affiliation(s)
- M J Martínez-Pérez
- Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, Pedro Cerbuna 12, 50009 Zaragoza, Spain
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129
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Jarmola A, Acosta VM, Jensen K, Chemerisov S, Budker D. Temperature- and magnetic-field-dependent longitudinal spin relaxation in nitrogen-vacancy ensembles in diamond. PHYSICAL REVIEW LETTERS 2012; 108:197601. [PMID: 23003089 DOI: 10.1103/physrevlett.108.197601] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Indexed: 06/01/2023]
Abstract
We present an experimental study of the longitudinal electron-spin relaxation time (T1) of negatively charged nitrogen-vacancy (NV) ensembles in diamond. T1 was studied as a function of temperature from 5 to 475 K and magnetic field from 0 to 630 G for several samples with various NV and nitrogen concentrations. Our studies reveal three processes responsible for T1 relaxation. Above room temperature, a two-phonon Raman process dominates; below room temperature, we observe an Orbach-type process with an activation energy of 73(4) meV, which closely matches the local vibrational modes of the NV center. At yet lower temperatures, sample dependent cross-relaxation processes dominate, resulting in temperature independent values of T1 from milliseconds to minutes. The value of T1 in this limit depends sensitively on the magnetic field and can be tuned by more than 1 order of magnitude.
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Affiliation(s)
- A Jarmola
- Department of Physics, University of California, Berkeley, California 94720, USA.
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130
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Ishikawa T, Fu KMC, Santori C, Acosta VM, Beausoleil RG, Watanabe H, Shikata S, Itoh KM. Optical and spin coherence properties of nitrogen-vacancy centers placed in a 100 nm thick isotopically purified diamond layer. NANO LETTERS 2012; 12:2083-2087. [PMID: 22404419 DOI: 10.1021/nl300350r] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We have studied optical and spin properties of near-surface nitrogen-vacancy (NV) centers incorporated during chemical vapor phase growth of isotopically purified (12)C single-crystal diamond layers. The spectral diffusion-limited line width of zero-phonon luminescence from the NV centers is 1.2 ± 0.5 GHz, a considerable improvement over that of NV centers formed by ion implantation and annealing. Enhanced spin dephasing times (T(2)* ≈ 90 μs, T(2) ≈ 1.7 ms) due to the reduction of (13)C nuclear spins persist even for NV centers placed within 100 nm of the surface.
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Affiliation(s)
- Toyofumi Ishikawa
- Graduate School of Fundamental Science and Technology, Keio University, Yokohama 223-8522, Japan
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131
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Decoherence-protected quantum gates for a hybrid solid-state spin register. Nature 2012; 484:82-6. [DOI: 10.1038/nature10900] [Citation(s) in RCA: 283] [Impact Index Per Article: 23.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 01/25/2012] [Indexed: 12/24/2022]
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132
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Creedon DL, Benmessaï K, Bowen WP, Tobar ME. Four-wave mixing from Fe3+ spins in sapphire. PHYSICAL REVIEW LETTERS 2012; 108:093902. [PMID: 22463638 DOI: 10.1103/physrevlett.108.093902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2011] [Indexed: 05/31/2023]
Abstract
Fe(3+) ions in sapphire exhibit an electron spin resonance which interacts strongly with high-Q whispering gallery modes at microwave frequencies. We report the first observation of a third-order paramagnetic nonlinear susceptibility in such a resonator at cryogenic temperatures and the first demonstration of four-wave mixing using this parametric nonlinearity. This observation of an all-microwave nonlinearity is an enabling step towards a host of quantum measurement and control applications which utilize spins in solids.
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Affiliation(s)
- Daniel L Creedon
- ARC Centre of Excellence for Engineered Quantum Systems, University of Western Australia, 35 Stirling Highway, Crawley, Western Australia 6009, Australia.
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133
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Tyryshkin AM, Tojo S, Morton JJL, Riemann H, Abrosimov NV, Becker P, Pohl HJ, Schenkel T, Thewalt MLW, Itoh KM, Lyon SA. Electron spin coherence exceeding seconds in high-purity silicon. NATURE MATERIALS 2011; 11:143-7. [PMID: 22138791 DOI: 10.1038/nmat3182] [Citation(s) in RCA: 191] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Accepted: 10/24/2011] [Indexed: 05/05/2023]
Abstract
Silicon is one of the most promising semiconductor materials for spin-based information processing devices. Its advanced fabrication technology facilitates the transition from individual devices to large-scale processors, and the availability of a (28)Si form with no magnetic nuclei overcomes a primary source of spin decoherence in many other materials. Nevertheless, the coherence lifetimes of electron spins in the solid state have typically remained several orders of magnitude lower than that achieved in isolated high-vacuum systems such as trapped ions. Here we examine electron spin coherence of donors in pure (28)Si material (residual (29)Si concentration <50 ppm) with donor densities of 10(14)-10(15) cm(-3). We elucidate three mechanisms for spin decoherence, active at different temperatures, and extract a coherence lifetime T(2) up to 2 s. In this regime, we find the electron spin is sensitive to interactions with other donor electron spins separated by ~200 nm. A magnetic field gradient suppresses such interactions, producing an extrapolated electron spin T(2) of 10 s at 1.8 K. These coherence lifetimes are without peer in the solid state and comparable to high-vacuum qubits, making electron spins of donors in silicon ideal components of quantum computers, or quantum memories for systems such as superconducting qubits.
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Affiliation(s)
- Alexei M Tyryshkin
- Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA
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134
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Kubo Y, Grezes C, Dewes A, Umeda T, Isoya J, Sumiya H, Morishita N, Abe H, Onoda S, Ohshima T, Jacques V, Dréau A, Roch JF, Diniz I, Auffeves A, Vion D, Esteve D, Bertet P. Hybrid quantum circuit with a superconducting qubit coupled to a spin ensemble. PHYSICAL REVIEW LETTERS 2011; 107:220501. [PMID: 22182018 DOI: 10.1103/physrevlett.107.220501] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Indexed: 05/31/2023]
Abstract
We report the experimental realization of a hybrid quantum circuit combining a superconducting qubit and an ensemble of electronic spins. The qubit, of the transmon type, is coherently coupled to the spin ensemble consisting of nitrogen-vacancy centers in a diamond crystal via a frequency-tunable superconducting resonator acting as a quantum bus. Using this circuit, we prepare a superposition of the qubit states that we store into collective excitations of the spin ensemble and retrieve back into the qubit later on. These results constitute a proof of concept of spin-ensemble based quantum memory for superconducting qubits.
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Affiliation(s)
- Y Kubo
- Quantronics group, SPEC (CNRS URA 2464), IRAMIS, DSM, CEA-Saclay, 91191 Gif-sur-Yvette, France
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135
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Abstract
Quantum computers hold the promise of massive performance enhancements across a range of applications, from cryptography and databases to revolutionary scientific simulation tools. Such computers would make use of the same quantum mechanical phenomena that pose limitations on the continued shrinking of conventional information processing devices. Many of the key requirements for quantum computing differ markedly from those of conventional computers. However, silicon, which plays a central part in conventional information processing, has many properties that make it a superb platform around which to build a quantum computer.
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136
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Coherent coupling of a superconducting flux qubit to an electron spin ensemble in diamond. Nature 2011; 478:221-4. [DOI: 10.1038/nature10462] [Citation(s) in RCA: 346] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2011] [Accepted: 08/10/2011] [Indexed: 11/09/2022]
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137
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Bermudez A, Jelezko F, Plenio MB, Retzker A. Electron-mediated nuclear-spin interactions between distant nitrogen-vacancy centers. PHYSICAL REVIEW LETTERS 2011; 107:150503. [PMID: 22107276 DOI: 10.1103/physrevlett.107.150503] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2011] [Indexed: 05/31/2023]
Abstract
We propose a scheme enabling controlled quantum coherent interactions between separated nitrogen-vacancy centers in diamond in the presence of strong magnetic fluctuations. The proposed scheme couples nuclear qubits employing the magnetic dipole-dipole interaction between the electron spins and, crucially, benefits from the suppression of the effect of environmental magnetic field fluctuations thanks to a strong microwave driving. This scheme provides a basic building block for a full-scale quantum-information processor or quantum simulator based on solid-state technology.
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Affiliation(s)
- A Bermudez
- Institut für Theoretische Physik, Albert-Einstein Allee 11, Universität Ulm, 89069 Ulm, Germany
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138
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Mal'shukov AG. Equilibrium circular photogalvanic effect in a hybrid superconductor-semiconductor system. PHYSICAL REVIEW LETTERS 2011; 107:146603. [PMID: 22107223 DOI: 10.1103/physrevlett.107.146603] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 07/30/2011] [Indexed: 05/31/2023]
Abstract
A dc electric current can be induced in a hybrid semiconductor-superconductor system under illumination of it by a circularly polarized light with the frequency below the energy of semiconductor interband transitions. In conditions when the light beam is unable to create real electron-hole excitations, this phenomenon is reminiscent of the Meissner effect in the static magnetic field. Such an effect can be employed in systems combining cavity photons and superconducting quantum circuits.
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Affiliation(s)
- A G Mal'shukov
- Institute of Spectroscopy, Russian Academy of Sciences, 142190, Troitsk, Moscow oblast, Russia
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139
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Ardavan A, Briggs GAD. Quantum control in spintronics. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2011; 369:3229-3248. [PMID: 21727123 DOI: 10.1098/rsta.2011.0009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Superposition and entanglement are uniquely quantum phenomena. Superposition incorporates a phase that contains information surpassing any classical mixture. Entanglement offers correlations between measurements in quantum systems that are stronger than any that would be possible classically. These give quantum computing its spectacular potential, but the implications extend far beyond quantum information processing. Early applications may be found in entanglement-enhanced sensing and metrology. Quantum spins in condensed matter offer promising candidates for investigating and exploiting superposition and entanglement, and enormous progress is being made in quantum control of such systems. In gallium arsenide (GaAs), individual electron spins can be manipulated and measured, and singlet-triplet states can be controlled in double-dot structures. In silicon, individual electron spins can be detected by ionization of phosphorus donors, and information can be transferred from electron spins to nuclear spins to provide long memory times. Electron and nuclear spins can be manipulated in nitrogen atoms incarcerated in fullerene molecules, which in turn can be assembled in ordered arrays. Spin states of charged nitrogen vacancy centres in diamond can be manipulated and read optically. Collective spin states in a range of materials systems offer scope for holographic storage of information. Conditions are now excellent for implementing superposition and entanglement in spintronic devices, thereby opening up a new era of quantum technologies.
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Affiliation(s)
- A Ardavan
- The Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, UK.
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140
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Hoi IC, Wilson CM, Johansson G, Palomaki T, Peropadre B, Delsing P. Demonstration of a single-photon router in the microwave regime. PHYSICAL REVIEW LETTERS 2011; 107:073601. [PMID: 21902392 DOI: 10.1103/physrevlett.107.073601] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Revised: 06/04/2011] [Indexed: 05/31/2023]
Abstract
We have embedded an artificial atom, a superconducting transmon qubit, in an open transmission line and investigated the strong scattering of incident microwave photons (∼6 GHz). When an input coherent state, with an average photon number N≪1 is on resonance with the artificial atom, we observe extinction of up to 99.6% in the forward propagating field. We use two-tone spectroscopy to study scattering from excited states and we observe electromagnetically induced transparency (EIT). We then use EIT to make a single-photon router, where we can control to what output port an incoming signal is delivered. The maximum on-off ratio is around 99% with a rise and fall time on the order of nanoseconds, consistent with theoretical expectations. The router can easily be extended to have multiple output ports and it can be viewed as a rudimentary quantum node, an important step towards building quantum information networks.
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Affiliation(s)
- Io-Chun Hoi
- MC2, Chalmers University of Technology, Göteborg, Sweden
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141
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Amsüss R, Koller C, Nöbauer T, Putz S, Rotter S, Sandner K, Schneider S, Schramböck M, Steinhauser G, Ritsch H, Schmiedmayer J, Majer J. Cavity QED with magnetically coupled collective spin states. PHYSICAL REVIEW LETTERS 2011; 107:060502. [PMID: 21902306 DOI: 10.1103/physrevlett.107.060502] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 05/03/2011] [Indexed: 05/31/2023]
Abstract
We report strong coupling between an ensemble of nitrogen-vacancy center electron spins in diamond and a superconducting microwave coplanar waveguide resonator. The characteristic scaling of the collective coupling strength with the square root of the number of emitters is observed directly. Additionally, we measure hyperfine coupling to (13)C nuclear spins, which is a first step towards a nuclear ensemble quantum memory. Using the dispersive shift of the cavity resonance frequency, we measure the relaxation time of the NV center at millikelvin temperatures in a nondestructive way.
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Affiliation(s)
- R Amsüss
- Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Austria
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142
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Brown RM, Tyryshkin AM, Porfyrakis K, Gauger EM, Lovett BW, Ardavan A, Lyon SA, Briggs GAD, Morton JJL. Coherent state transfer between an electron and nuclear spin in (15)N@C(60). PHYSICAL REVIEW LETTERS 2011; 106:110504. [PMID: 21469852 DOI: 10.1103/physrevlett.106.110504] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2010] [Indexed: 05/30/2023]
Abstract
Electron spin qubits in molecular systems offer high reproducibility and the ability to self-assemble into larger architectures. However, interactions between neighboring qubits are "always on," and although the electron spin coherence times can be several hundred microseconds, these are still much shorter than typical times for nuclear spins. Here we implement an electron-nuclear hybrid scheme which uses coherent transfer between electron and nuclear spin degrees of freedom in order to both effectively turn on or off interqubit coupling mediated by dipolar interactions and benefit from the long nuclear spin decoherence times (T(2n)). We transfer qubit states between the electron and (15)N nuclear spin in (15)N@C(60) with a two-way process fidelity of 88%, using a series of tuned microwave and radio frequency pulses and measure a nuclear spin coherence lifetime of over 100 ms.
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Affiliation(s)
- Richard M Brown
- Department of Materials, Oxford University, Oxford OX1 3PH, United Kingdom.
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143
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Marcos D, Wubs M, Taylor JM, Aguado R, Lukin MD, Sørensen AS. Coupling nitrogen-vacancy centers in diamond to superconducting flux qubits. PHYSICAL REVIEW LETTERS 2010; 105:210501. [PMID: 21231275 DOI: 10.1103/physrevlett.105.210501] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2010] [Indexed: 05/30/2023]
Abstract
We propose a method to achieve coherent coupling between nitrogen-vacancy (NV) centers in diamond and superconducting (SC) flux qubits. The resulting coupling can be used to create a coherent interaction between the spin states of distant NV centers mediated by the flux qubit. Furthermore, the magnetic coupling can be used to achieve a coherent transfer of quantum information between the flux qubit and an ensemble of NV centers. This enables a long-term memory for a SC quantum processor and possibly an interface between SC qubits and light.
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Affiliation(s)
- D Marcos
- Theory and Simulation of Materials Department, Instituto de Ciencia de Materiales de Madrid, CSIC, Cantoblanco 28049, Madrid, Spain
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144
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145
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Schuster DI, Sears AP, Ginossar E, DiCarlo L, Frunzio L, Morton JJL, Wu H, Briggs GAD, Buckley BB, Awschalom DD, Schoelkopf RJ. High-cooperativity coupling of electron-spin ensembles to superconducting cavities. PHYSICAL REVIEW LETTERS 2010; 105:140501. [PMID: 21230817 DOI: 10.1103/physrevlett.105.140501] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/11/2010] [Indexed: 05/30/2023]
Abstract
Electron spins in solids are promising candidates for quantum memories for superconducting qubits because they can have long coherence times, large collective couplings, and many qubits could be encoded into spin waves of a single ensemble. We demonstrate the coupling of electron-spin ensembles to a superconducting transmission-line cavity at strengths greatly exceeding the cavity decay rates and comparable to the spin linewidths. We also perform broadband spectroscopy of ruby (Al₂O₃:Cr(3+)) at millikelvin temperatures and low powers, using an on-chip feedline. In addition, we observe hyperfine structure in diamond P1 centers.
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Affiliation(s)
- D I Schuster
- Department of Applied Physics and Physics, Yale University, New Haven, Connecticut 06511, USA
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146
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Wu H, George RE, Wesenberg JH, Mølmer K, Schuster DI, Schoelkopf RJ, Itoh KM, Ardavan A, Morton JJL, Briggs GAD. Storage of multiple coherent microwave excitations in an electron spin ensemble. PHYSICAL REVIEW LETTERS 2010; 105:140503. [PMID: 21230819 DOI: 10.1103/physrevlett.105.140503] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Indexed: 05/30/2023]
Abstract
Strong coupling between a microwave photon and electron spins, which could enable a long-lived quantum memory element for superconducting qubits, is possible using a large ensemble of spins. This represents an inefficient use of resources unless multiple photons, or qubits, can be orthogonally stored and retrieved. Here we employ holographic techniques to realize a coherent memory using a pulsed magnetic field gradient and demonstrate the storage and retrieval of up to 100 weak 10 GHz coherent excitations in collective states of an electron spin ensemble. We further show that such collective excitations in the electron spin can then be stored in nuclear spin states, which offer coherence times in excess of seconds.
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Affiliation(s)
- Hua Wu
- Department of Materials, Oxford University, Oxford OX1 3PH, United Kingdom
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147
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