1
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Lysne NK, Niedermeyer JF, Wilson AC, Slichter DH, Leibfried D. Individual Addressing and State Readout of Trapped Ions Utilizing Radio-Frequency Micromotion. PHYSICAL REVIEW LETTERS 2024; 133:033201. [PMID: 39094141 DOI: 10.1103/physrevlett.133.033201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 05/20/2024] [Indexed: 08/04/2024]
Abstract
Excess "micromotion" of trapped ions due to the residual radio-frequency (rf) trapping field at their location is often undesirable and is usually carefully minimized. Here, we induce precise amounts of excess micromotion on individual ions by adjusting the local static electric field they experience. Micromotion modulates the coupling of an ion to laser fields, ideally tuning it from its maximum value to zero as the ion is moved away from the trap's rf null. We use tunable micromotion to vary the Rabi frequency of stimulated Raman transitions over two orders of magnitude, and to individually control the rates of resonant fluorescence from three ions under global laser illumination without any changes to the driving light fields. The technique is amenable to situations where addressing individual ions with focused laser beams is challenging, such as tightly packed linear ion strings or two-dimensional ion arrays illuminated from the side.
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2
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Jeong J, Jung C, Kim T, Cho DD. Using machine learning to improve multi-qubit state discrimination of trapped ions from uncertain EMCCD measurements. OPTICS EXPRESS 2023; 31:35113-35130. [PMID: 37859250 DOI: 10.1364/oe.491301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 08/15/2023] [Indexed: 10/21/2023]
Abstract
This paper proposes a residual network (ResNet)-based convolutional neural network (CNN) model to improve multi-qubit state measurements using an electron-multiplying charge-coupled device (EMCCD). The CNN model is developed to simultaneously use the intensity of pixel values and the shape of ion images in determining the quantum states of ions. In contrast, conventional methods use only the intensity values. In our experiments, the proposed model achieved a 99.53±0.14% mean individual measurement fidelity (MIMF) of 4 trapped ions, reducing the error by 46% when compared to the MIMF of maximum likelihood estimation method of 99.13±0.08%. In addition, it is experimentally shown that the model is also robust against the ion image drift, which was tested by intentionally shifting the ion images.
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3
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Leu AD, Gely MF, Weber MA, Smith MC, Nadlinger DP, Lucas DM. Fast, High-Fidelity Addressed Single-Qubit Gates Using Efficient Composite Pulse Sequences. PHYSICAL REVIEW LETTERS 2023; 131:120601. [PMID: 37802949 DOI: 10.1103/physrevlett.131.120601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/29/2023] [Indexed: 10/08/2023]
Abstract
We use electronic microwave control methods to implement addressed single-qubit gates with high speed and fidelity, for ^{43}Ca^{+} hyperfine "atomic clock" qubits in a cryogenic (100 K) surface trap. For a single qubit, we benchmark an error of 1.5×10^{-6} per Clifford gate (implemented using 600 ns π/2 pulses). For 2 qubits in the same trap zone (ion separation 5 μm), we use a spatial microwave field gradient, combined with an efficient four-pulse scheme, to implement independent addressed gates. Parallel randomized benchmarking on both qubits yields an average error 3.4×10^{-5} per addressed π/2 gate. The scheme scales theoretically to larger numbers of qubits in a single register.
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Affiliation(s)
- A D Leu
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - M F Gely
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - M A Weber
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - M C Smith
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D P Nadlinger
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D M Lucas
- Clarendon Laboratory, Department of Physics, University of Oxford, Parks Road, Oxford OX1 3PU, United Kingdom
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4
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Srinivas R, Löschnauer CM, Malinowski M, Hughes AC, Nourshargh R, Negnevitsky V, Allcock DTC, King SA, Matthiesen C, Harty TP, Ballance CJ. Coherent Control of Trapped-Ion Qubits with Localized Electric Fields. PHYSICAL REVIEW LETTERS 2023; 131:020601. [PMID: 37505962 DOI: 10.1103/physrevlett.131.020601] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Accepted: 05/23/2023] [Indexed: 07/30/2023]
Abstract
We present a new method for coherent control of trapped ion qubits in separate interaction regions of a multizone trap by simultaneously applying an electric field and a spin-dependent gradient. Both the phase and amplitude of the effective single-qubit rotation depend on the electric field, which can be localized to each zone. We demonstrate this interaction on a single ion using both laser-based and magnetic-field gradients in a surface-electrode ion trap, and measure the localization of the electric field.
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Affiliation(s)
- R Srinivas
- Oxford Ionics, Oxford, OX5 1PF, United Kingdom
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom
| | | | | | - A C Hughes
- Oxford Ionics, Oxford, OX5 1PF, United Kingdom
| | | | | | - D T C Allcock
- Oxford Ionics, Oxford, OX5 1PF, United Kingdom
- Department of Physics, University of Oregon, Eugene, Oregon 97403, USA
| | - S A King
- Oxford Ionics, Oxford, OX5 1PF, United Kingdom
| | | | - T P Harty
- Oxford Ionics, Oxford, OX5 1PF, United Kingdom
| | - C J Ballance
- Oxford Ionics, Oxford, OX5 1PF, United Kingdom
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford, OX1 3PU, United Kingdom
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5
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Srinivas R, Burd SC, Knaack HM, Sutherland RT, Kwiatkowski A, Glancy S, Knill E, Wineland DJ, Leibfried D, Wilson AC, Allcock DTC, Slichter DH. High-fidelity laser-free universal control of trapped ion qubits. Nature 2021; 597:209-213. [PMID: 34497396 PMCID: PMC11165722 DOI: 10.1038/s41586-021-03809-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 07/07/2021] [Indexed: 11/09/2022]
Abstract
Universal control of multiple qubits-the ability to entangle qubits and to perform arbitrary individual qubit operations1-is a fundamental resource for quantum computing2, simulation3 and networking4. Qubits realized in trapped atomic ions have shown the highest-fidelity two-qubit entangling operations5-7 and single-qubit rotations8 so far. Universal control of trapped ion qubits has been separately demonstrated using tightly focused laser beams9-12 or by moving ions with respect to laser beams13-15, but at lower fidelities. Laser-free entangling methods16-20 may offer improved scalability by harnessing microwave technology developed for wireless communications, but so far their performance has lagged the best reported laser-based approaches. Here we demonstrate high-fidelity laser-free universal control of two trapped-ion qubits by creating both symmetric and antisymmetric maximally entangled states with fidelities of [Formula: see text] and [Formula: see text], respectively (68 per cent confidence level), corrected for initialization error. We use a scheme based on radiofrequency magnetic field gradients combined with microwave magnetic fields that is robust against multiple sources of decoherence and usable with essentially any trapped ion species. The scheme has the potential to perform simultaneous entangling operations on multiple pairs of ions in a large-scale trapped-ion quantum processor without increasing control signal power or complexity. Combining this technology with low-power laser light delivered via trap-integrated photonics21,22 and trap-integrated photon detectors for qubit readout23,24 provides an opportunity for scalable, high-fidelity, fully chip-integrated trapped-ion quantum computing.
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Affiliation(s)
- R Srinivas
- National Institute of Standards and Technology, Boulder, CO, USA.
- Department of Physics, University of Colorado, Boulder, CO, USA.
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, UK.
| | - S C Burd
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado, Boulder, CO, USA
- Department of Physics, Stanford University, Stanford, CA, USA
| | - H M Knaack
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado, Boulder, CO, USA
| | - R T Sutherland
- Physics Division, Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, CA, USA
- Department of Electrical and Computer Engineering, University of Texas at San Antonio, San Antonio, TX, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, USA
| | - A Kwiatkowski
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado, Boulder, CO, USA
| | - S Glancy
- National Institute of Standards and Technology, Boulder, CO, USA
| | - E Knill
- National Institute of Standards and Technology, Boulder, CO, USA
- Center for Theory of Quantum Matter, University of Colorado, Boulder, CO, USA
| | - D J Wineland
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado, Boulder, CO, USA
- Department of Physics, University of Oregon, Eugene, OR, USA
| | - D Leibfried
- National Institute of Standards and Technology, Boulder, CO, USA
| | - A C Wilson
- National Institute of Standards and Technology, Boulder, CO, USA
| | - D T C Allcock
- National Institute of Standards and Technology, Boulder, CO, USA
- Department of Physics, University of Colorado, Boulder, CO, USA
- Department of Physics, University of Oregon, Eugene, OR, USA
| | - D H Slichter
- National Institute of Standards and Technology, Boulder, CO, USA.
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6
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Bardin JC, Slichter DH, Reilly DJ. Microwaves in Quantum Computing. IEEE JOURNAL OF MICROWAVES 2021; 1:10.1109/JMW.2020.3034071. [PMID: 34355217 PMCID: PMC8335598 DOI: 10.1109/jmw.2020.3034071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Quantum information processing systems rely on a broad range of microwave technologies and have spurred development of microwave devices and methods in new operating regimes. Here we review the use of microwave signals and systems in quantum computing, with specific reference to three leading quantum computing platforms: trapped atomic ion qubits, spin qubits in semiconductors, and superconducting qubits. We highlight some key results and progress in quantum computing achieved through the use of microwave systems, and discuss how quantum computing applications have pushed the frontiers of microwave technology in some areas. We also describe open microwave engineering challenges for the construction of large-scale, fault-tolerant quantum computers.
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Affiliation(s)
- Joseph C Bardin
- Department of Electrical and Computer Engineering, University of Massachusetts Amherst, Amherst, MA 01003 USA
- Google LLC, Goleta, CA 93117 USA
| | - Daniel H Slichter
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305 USA
| | - David J Reilly
- Microsoft Inc., Microsoft Quantum Sydney, The University of Sydney, Sydney, NSW 2050, Australia
- ARC Centre of Excellence for Engineered Quantum Systems (EQuS), School of Physics, The University of Sydney, Sydney, NSW 2050, Australia
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7
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Kaufmann P, Gloger TF, Kaufmann D, Johanning M, Wunderlich C. High-Fidelity Preservation of Quantum Information During Trapped-Ion Transport. PHYSICAL REVIEW LETTERS 2018; 120:010501. [PMID: 29350951 DOI: 10.1103/physrevlett.120.010501] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Indexed: 06/07/2023]
Abstract
A promising scheme for building scalable quantum simulators and computers is the synthesis of a scalable system using interconnected subsystems. A prerequisite for this approach is the ability to faithfully transfer quantum information between subsystems. With trapped atomic ions, this can be realized by transporting ions with quantum information encoded into their internal states. Here, we measure with high precision the fidelity of quantum information encoded into hyperfine states of a ^{171}Yb^{+} ion during ion transport in a microstructured Paul trap. Ramsey spectroscopy of the ion's internal state is interleaved with up to 4000 transport operations over a distance of 280 μm each taking 12.8 μs. We obtain a state fidelity of 99.9994( _{-7}^{+6})% per ion transport.
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Affiliation(s)
- Peter Kaufmann
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - Timm F Gloger
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - Delia Kaufmann
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - Michael Johanning
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - Christof Wunderlich
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
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8
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Lekitsch B, Weidt S, Fowler AG, Mølmer K, Devitt SJ, Wunderlich C, Hensinger WK. Blueprint for a microwave trapped ion quantum computer. SCIENCE ADVANCES 2017; 3:e1601540. [PMID: 28164154 PMCID: PMC5287699 DOI: 10.1126/sciadv.1601540] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 12/15/2016] [Indexed: 06/02/2023]
Abstract
The availability of a universal quantum computer may have a fundamental impact on a vast number of research fields and on society as a whole. An increasingly large scientific and industrial community is working toward the realization of such a device. An arbitrarily large quantum computer may best be constructed using a modular approach. We present a blueprint for a trapped ion-based scalable quantum computer module, making it possible to create a scalable quantum computer architecture based on long-wavelength radiation quantum gates. The modules control all operations as stand-alone units, are constructed using silicon microfabrication techniques, and are within reach of current technology. To perform the required quantum computations, the modules make use of long-wavelength radiation-based quantum gate technology. To scale this microwave quantum computer architecture to a large size, we present a fully scalable design that makes use of ion transport between different modules, thereby allowing arbitrarily many modules to be connected to construct a large-scale device. A high error-threshold surface error correction code can be implemented in the proposed architecture to execute fault-tolerant operations. With appropriate adjustments, the proposed modules are also suitable for alternative trapped ion quantum computer architectures, such as schemes using photonic interconnects.
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Affiliation(s)
- Bjoern Lekitsch
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, U.K
| | - Sebastian Weidt
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, U.K
| | | | - Klaus Mølmer
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - Simon J. Devitt
- Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 315-0198, Japan
| | - Christof Wunderlich
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
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9
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Harty TP, Sepiol MA, Allcock DTC, Ballance CJ, Tarlton JE, Lucas DM. High-Fidelity Trapped-Ion Quantum Logic Using Near-Field Microwaves. PHYSICAL REVIEW LETTERS 2016; 117:140501. [PMID: 27740823 DOI: 10.1103/physrevlett.117.140501] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Indexed: 06/06/2023]
Abstract
We demonstrate a two-qubit logic gate driven by near-field microwaves in a room-temperature microfabricated surface ion trap. We introduce a dynamically decoupled gate method, which stabilizes the qubits against fluctuating energy shifts and avoids the need to null the microwave field. We use the gate to produce a Bell state with fidelity 99.7(1)%, after accounting for state preparation and measurement errors. The gate is applied directly to ^{43}Ca^{+} hyperfine "atomic clock" qubits (coherence time T_{2}^{*}≈50 s) using the oscillating magnetic field gradient produced by an integrated microwave electrode.
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Affiliation(s)
- T P Harty
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - M A Sepiol
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D T C Allcock
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - C J Ballance
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - J E Tarlton
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
| | - D M Lucas
- Department of Physics, University of Oxford, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, United Kingdom
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10
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Piltz C, Sriarunothai T, Ivanov SS, Wölk S, Wunderlich C. Versatile microwave-driven trapped ion spin system for quantum information processing. SCIENCE ADVANCES 2016; 2:e1600093. [PMID: 27419233 PMCID: PMC4942346 DOI: 10.1126/sciadv.1600093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2016] [Accepted: 06/14/2016] [Indexed: 05/11/2023]
Abstract
Using trapped atomic ions, we demonstrate a tailored and versatile effective spin system suitable for quantum simulations and universal quantum computation. By simply applying microwave pulses, selected spins can be decoupled from the remaining system and, thus, can serve as a quantum memory, while simultaneously, other coupled spins perform conditional quantum dynamics. Also, microwave pulses can change the sign of spin-spin couplings, as well as their effective strength, even during the course of a quantum algorithm. Taking advantage of the simultaneous long-range coupling between three spins, a coherent quantum Fourier transform-an essential building block for many quantum algorithms-is efficiently realized. This approach, which is based on microwave-driven trapped ions and is complementary to laser-based methods, opens a new route to overcoming technical and physical challenges in the quest for a quantum simulator and a quantum computer.
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Affiliation(s)
- Christian Piltz
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - Theeraphot Sriarunothai
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - Svetoslav S. Ivanov
- Department of Physics, Sofia University, 5 James Bourchier Boulevard, 1164 Sofia, Bulgaria
| | - Sabine Wölk
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
| | - Christof Wunderlich
- Department Physik, Naturwissenschaftlich-Technische Fakultät, Universität Siegen, 57068 Siegen, Germany
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11
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Wang Y, Kumar A, Wu TY, Weiss DS. Single-qubit gates based on targeted phase shifts in a 3D neutral atom array. Science 2016; 352:1562-5. [DOI: 10.1126/science.aaf2581] [Citation(s) in RCA: 95] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 05/10/2016] [Indexed: 11/02/2022]
Affiliation(s)
- Yang Wang
- Department of Physics, Pennsylvania State University, University Park, PA, USA
| | - Aishwarya Kumar
- Department of Physics, Pennsylvania State University, University Park, PA, USA
| | - Tsung-Yao Wu
- Department of Physics, Pennsylvania State University, University Park, PA, USA
| | - David S. Weiss
- Department of Physics, Pennsylvania State University, University Park, PA, USA
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12
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Friis N, Melnikov AA, Kirchmair G, Briegel HJ. Coherent controlization using superconducting qubits. Sci Rep 2015; 5:18036. [PMID: 26667893 PMCID: PMC4678369 DOI: 10.1038/srep18036] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Accepted: 11/10/2015] [Indexed: 11/08/2022] Open
Abstract
Coherent controlization, i.e., coherent conditioning of arbitrary single- or multi-qubit operations on the state of one or more control qubits, is an important ingredient for the flexible implementation of many algorithms in quantum computation. This is of particular significance when certain subroutines are changing over time or when they are frequently modified, such as in decision-making algorithms for learning agents. We propose a scheme to realize coherent controlization for any number of superconducting qubits coupled to a microwave resonator. For two and three qubits, we present an explicit construction that is of high relevance for quantum learning agents. We demonstrate the feasibility of our proposal, taking into account loss, dephasing, and the cavity self-Kerr effect.
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Affiliation(s)
- Nicolai Friis
- Institute for Theoretical Physics, University of Innsbruck, Technikerstraße 21a, A-6020 Innsbruck, Austria
| | - Alexey A. Melnikov
- Institute for Theoretical Physics, University of Innsbruck, Technikerstraße 21a, A-6020 Innsbruck, Austria
- Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Technikerstraße 21a, A-6020 Innsbruck, Austria
| | - Gerhard Kirchmair
- Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences, Technikerstraße 21a, A-6020 Innsbruck, Austria
- Institute for Experimental Physics, University of Innsbruck, Technikerstraße 25, A-6020 Innsbruck, Austria
| | - Hans J. Briegel
- Institute for Theoretical Physics, University of Innsbruck, Technikerstraße 21a, A-6020 Innsbruck, Austria
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13
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Erratum: A trapped-ion-based quantum byte with 10−5 next-neighbour cross-talk. Nat Commun 2015; 6:8908. [DOI: 10.1038/ncomms9908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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14
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Weidt S, Randall J, Webster SC, Standing ED, Rodriguez A, Webb AE, Lekitsch B, Hensinger WK. Ground-State Cooling of a Trapped Ion Using Long-Wavelength Radiation. PHYSICAL REVIEW LETTERS 2015; 115:013002. [PMID: 26182094 DOI: 10.1103/physrevlett.115.013002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Indexed: 06/04/2023]
Abstract
We demonstrate ground-state cooling of a trapped ion using radio-frequency (rf) radiation. This is a powerful tool for the implementation of quantum operations, where rf or microwave radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of n[over ¯]=0.13(4) after sideband cooling, corresponding to a ground-state occupation probability of 88(7)%. After preparing in the vibrational ground state, we demonstrate motional state engineering by driving Rabi oscillations between the |n=0⟩ and |n=1⟩ Fock states. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost 2 orders of magnitude compared with our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system.
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Affiliation(s)
- S Weidt
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
| | - J Randall
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
- QOLS, Blackett Laboratory, Imperial College London, London SW7 2BW, United Kingdom
| | - S C Webster
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
| | - E D Standing
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
| | - A Rodriguez
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
| | - A E Webb
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
| | - B Lekitsch
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
| | - W K Hensinger
- Department of Physics and Astronomy, University of Sussex, Brighton BN1 9QH, United Kingdom
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