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Jeon H, Kang J, Kim J, Choi W, Kim K, Kim T. Experimental realization of entangled coherent states in two-dimensional harmonic oscillators of a trapped ion. Sci Rep 2024; 14:6847. [PMID: 38514797 DOI: 10.1038/s41598-024-57391-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/18/2024] [Indexed: 03/23/2024] Open
Abstract
Entangled coherent states play pivotal roles in various fields such as quantum computation, quantum communication, and quantum sensing. We experimentally demonstrate the generation of entangled coherent states with the two-dimensional motion of a trapped ion system. Using Raman transitions with appropriate detunings, we simultaneously drive the red and blue sidebands of the two transverse axes of a single trapped ion and observe multi-periodic entanglement and disentanglement of its spin and two-dimensional motion. Then, by measuring the spin state, we herald entangled coherent states of the transverse motions of the trapped ion and observe the corresponding modulation in the parity of the phonon distribution of one of the harmonic oscillators. Lastly, we trap two ions in a linear chain and realize Mølmer-Sørensen gate using two-dimensional motion.
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Affiliation(s)
- Honggi Jeon
- Department of Computer Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Automation and Systems Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jiyong Kang
- Department of Computer Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Automation and Systems Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Jaeun Kim
- Department of Computer Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Automation and Systems Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Wonhyeong Choi
- Department of Computer Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Automation and Systems Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Kyunghye Kim
- Department of Computer Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea
- Automation and Systems Research Institute, Seoul National University, Seoul, 08826, Republic of Korea
| | - Taehyun Kim
- Department of Computer Science and Engineering, Seoul National University, Seoul, 08826, Republic of Korea.
- Automation and Systems Research Institute, Seoul National University, Seoul, 08826, Republic of Korea.
- Inter-university Semiconductor Research Center, Seoul National University, Seoul, 08826, Republic of Korea.
- Institute of Computer Technology, Seoul National University, Seoul, 08826, Republic of Korea.
- Institute of Applied Physics, Seoul National University, Seoul, 08826, Republic of Korea.
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2
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Whitlow J, Jia Z, Wang Y, Fang C, Kim J, Brown KR. Quantum simulation of conical intersections using trapped ions. Nat Chem 2023; 15:1509-1514. [PMID: 37640856 DOI: 10.1038/s41557-023-01303-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 07/21/2023] [Indexed: 08/31/2023]
Abstract
Conical intersections often control the reaction products of photochemical processes and occur when two electronic potential energy surfaces intersect. Theory predicts that the conical intersection will result in a geometric phase for a wavepacket on the ground potential energy surface, and although conical intersections have been observed experimentally, the geometric phase has not been directly observed in a molecular system. Here we use a trapped atomic ion system to perform a quantum simulation of a conical intersection. The ion's internal state serves as the electronic state, and the motion of the atomic nuclei is encoded into the motion of the ions. The simulated electronic potential is constructed by applying state-dependent optical forces to the ion. We experimentally observe a clear manifestation of the geometric phase using adiabatic state preparation followed by motional state measurement. Our experiment shows the advantage of combining spin and motion degrees for quantum simulation of chemical reactions.
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Affiliation(s)
- Jacob Whitlow
- Duke Quantum Center, Duke University, Durham, NC, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Zhubing Jia
- Duke Quantum Center, Duke University, Durham, NC, USA
- Department of Physics, Duke University, Durham, NC, USA
- Department of Physics, The University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Ye Wang
- Duke Quantum Center, Duke University, Durham, NC, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
- School of Physical Sciences, University of Science and Technology of China, Hefei, China
| | - Chao Fang
- Duke Quantum Center, Duke University, Durham, NC, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Jungsang Kim
- Duke Quantum Center, Duke University, Durham, NC, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
- Department of Physics, Duke University, Durham, NC, USA
- IonQ, Inc., College Park, MD, USA
| | - Kenneth R Brown
- Duke Quantum Center, Duke University, Durham, NC, USA.
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
- Department of Physics, Duke University, Durham, NC, USA.
- Department of Chemistry, Duke University, Durham, NC, USA.
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3
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MacDonell RJ, Navickas T, Wohlers-Reichel TF, Valahu CH, Rao AD, Millican MJ, Currington MA, Biercuk MJ, Tan TR, Hempel C, Kassal I. Predicting molecular vibronic spectra using time-domain analog quantum simulation. Chem Sci 2023; 14:9439-9451. [PMID: 37712022 PMCID: PMC10498668 DOI: 10.1039/d3sc02453a] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2023] [Accepted: 08/09/2023] [Indexed: 09/16/2023] Open
Abstract
Spectroscopy is one of the most accurate probes of the molecular world. However, predicting molecular spectra accurately is computationally difficult because of the presence of entanglement between electronic and nuclear degrees of freedom. Although quantum computers promise to reduce this computational cost, existing quantum approaches rely on combining signals from individual eigenstates, an approach whose cost grows exponentially with molecule size. Here, we introduce a method for scalable analog quantum simulation of molecular spectroscopy: by performing simulations in the time domain, the number of required measurements depends on the desired spectral range and resolution, not molecular size. Our approach can treat more complicated molecular models than previous ones, requires fewer approximations, and can be extended to open quantum systems with minimal overhead. We present a direct mapping of the underlying problem of time-domain simulation of molecular spectra to the degrees of freedom and control fields available in a trapped-ion quantum simulator. We experimentally demonstrate our algorithm on a trapped-ion device, exploiting both intrinsic electronic and motional degrees of freedom, showing excellent quantitative agreement for a single-mode vibronic photoelectron spectrum of SO2.
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Affiliation(s)
- Ryan J MacDonell
- School of Chemistry, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
- University of Sydney Nano Institute, University of Sydney NSW 2006 Australia
| | - Tomas Navickas
- School of Physics, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
| | - Tim F Wohlers-Reichel
- School of Physics, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
| | - Christophe H Valahu
- School of Physics, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
| | - Arjun D Rao
- School of Physics, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
| | - Maverick J Millican
- School of Physics, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
| | | | - Michael J Biercuk
- School of Physics, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
| | - Ting Rei Tan
- School of Physics, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
| | - Cornelius Hempel
- School of Physics, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
- ETH Zurich-PSI Quantum Computing Hub, Laboratory for Nano and Quantum Technologies (LNQ), Paul Scherrer Institut 5232 Villigen Switzerland
| | - Ivan Kassal
- School of Chemistry, University of Sydney NSW 2006 Australia
- ARC Centre of Excellence for Engineered Quantum Systems, University of Sydney NSW 2006 Australia
- University of Sydney Nano Institute, University of Sydney NSW 2006 Australia
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4
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Solaro C, Debavelaere C, Cladé P, Guellati-Khelifa S. Atom Interferometer Driven by a Picosecond Frequency Comb. PHYSICAL REVIEW LETTERS 2022; 129:173204. [PMID: 36332244 DOI: 10.1103/physrevlett.129.173204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
We demonstrate a light-pulse atom interferometer based on the diffraction of free-falling atoms by a picosecond frequency-comb laser. More specifically, we coherently split and recombine wave packets of cold ^{87}Rb atoms by driving stimulated Raman transitions between the |5s ^{2}S_{1/2},F=1⟩ and |5s ^{2}S_{1/2},F=2⟩ hyperfine states, using two trains of picosecond pulses in a counterpropagating geometry. We study the impact of the pulses' length as well as the interrogation time onto the contrast of the atom interferometer. Our experimental data are well reproduced by a numerical simulation based on an effective coupling that depends on the overlap between the pulses and the atomic cloud. These results pave the way for extending light-pulse interferometry to transitions in other spectral regions and therefore to other species, for new possibilities in metrology, sensing of gravito-inertial effects, and tests of fundamental physics.
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Affiliation(s)
- Cyrille Solaro
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-Université PSL, Collège de France, 75005 Paris, France
| | - Clément Debavelaere
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-Université PSL, Collège de France, 75005 Paris, France
| | - Pierre Cladé
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-Université PSL, Collège de France, 75005 Paris, France
| | - Saïda Guellati-Khelifa
- Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-Université PSL, Collège de France, 75005 Paris, France
- Conservatoire National des Arts et Métiers, 75003 Paris, France
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5
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Li RR, He R, Cui JM, Chen Y, Ye WR, Chen YL, Huang YF, Li CF, Guo GC. A versatile multi-tone laser system for manipulating atomic qubits based on a fiber Mach-Zehnder modulator and second harmonic generation. OPTICS EXPRESS 2022; 30:30098-30107. [PMID: 36242120 DOI: 10.1364/oe.462737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Accepted: 07/19/2022] [Indexed: 06/16/2023]
Abstract
Stimulated Raman transition is a fundamental method to coherently manipulate quantum states in different physical systems. Phase-coherent dichromatic radiation fields matching the energy level splitting are the key to realizing stimulated Raman transition. Here we demonstrate a flexible-tuning, spectrum-clean and fiber-compatible method to generate a highly phase-coherent and high-power multi-tone laser. This method features the utilization of a broadband fiber Mach-Zehnder modulator working at carrier suppression condition and second harmonic generation. We generate a multi-tone continuous-wave 532 nm laser with a power of 1.5 Watts and utilize it to manipulate the spin and motional states of a trapped 171Yb+ ion via stimulated Raman transition. For spin state manipulation, we acquire an effective Rabi frequency of 2π × 662.3 kHz. Due to the broad bandwidth of the fiber modulator and nonlinear crystal, the frequency gap between tones can be flexibly tuned. Benefiting from the features above, this method can manipulate 171Yb+ and 137Ba+ simultaneously in the multi-species ion trap and has potential to be widely applied in atomic, molecular and optical physics.
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6
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Maksymov IS, Huy Nguyen BQ, Pototsky A, Suslov S. Acoustic, Phononic, Brillouin Light Scattering and Faraday Wave-Based Frequency Combs: Physical Foundations and Applications. SENSORS (BASEL, SWITZERLAND) 2022; 22:3921. [PMID: 35632330 PMCID: PMC9143010 DOI: 10.3390/s22103921] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/16/2022] [Accepted: 05/20/2022] [Indexed: 11/16/2022]
Abstract
Frequency combs (FCs)-spectra containing equidistant coherent peaks-have enabled researchers and engineers to measure the frequencies of complex signals with high precision, thereby revolutionising the areas of sensing, metrology and communications and also benefiting the fundamental science. Although mostly optical FCs have found widespread applications thus far, in general FCs can be generated using waves other than light. Here, we review and summarise recent achievements in the emergent field of acoustic frequency combs (AFCs), including phononic FCs and relevant acousto-optical, Brillouin light scattering and Faraday wave-based techniques that have enabled the development of phonon lasers, quantum computers and advanced vibration sensors. In particular, our discussion is centred around potential applications of AFCs in precision measurements in various physical, chemical and biological systems in conditions where using light, and hence optical FCs, faces technical and fundamental limitations, which is, for example, the case in underwater distance measurements and biomedical imaging applications. This review article will also be of interest to readers seeking a discussion of specific theoretical aspects of different classes of AFCs. To that end, we support the mainstream discussion by the results of our original analysis and numerical simulations that can be used to design the spectra of AFCs generated using oscillations of gas bubbles in liquids, vibrations of liquid drops and plasmonic enhancement of Brillouin light scattering in metal nanostructures. We also discuss the application of non-toxic room-temperature liquid-metal alloys in the field of AFC generation.
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Affiliation(s)
- Ivan S. Maksymov
- Optical Sciences Centre, Swinburne University of Technology, Hawthorn, VIC 3122, Australia;
| | - Bui Quoc Huy Nguyen
- Optical Sciences Centre, Swinburne University of Technology, Hawthorn, VIC 3122, Australia;
| | - Andrey Pototsky
- Department of Mathematics, Swinburne University of Technology, Hawthorn, VIC 3122, Australia; (A.P.); (S.S.)
| | - Sergey Suslov
- Department of Mathematics, Swinburne University of Technology, Hawthorn, VIC 3122, Australia; (A.P.); (S.S.)
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7
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Wang P, Zhang J, Luan CY, Um M, Wang Y, Qiao M, Xie T, Zhang JN, Cabello A, Kim K. Significant loophole-free test of Kochen-Specker contextuality using two species of atomic ions. SCIENCE ADVANCES 2022; 8:eabk1660. [PMID: 35138888 PMCID: PMC8827658 DOI: 10.1126/sciadv.abk1660] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Accepted: 12/16/2021] [Indexed: 05/28/2023]
Abstract
Quantum measurements cannot be thought of as revealing preexisting results, even when they do not disturb any other measurement in the same trial. This feature is called contextuality and is crucial for the quantum advantage in computing. Here, we report the observation of quantum contextuality simultaneously free of the detection, sharpness, and compatibility loopholes. The detection and sharpness loopholes are closed by adopting a hybrid two-ion system and highly efficient fluorescence measurements offering a detection efficiency of 100% and a measurement repeatability of >98%. The compatibility loophole is closed by targeting correlations between observables for two different ions in a Paul trap, a 171Yb+ ion and a 138Ba+ ion, chosen so measurements on each ion use different operation laser wavelengths, fluorescence wavelengths, and detectors. The experimental results show a violation of the bound for the most adversarial noncontextual models and open a way to certify quantum systems.
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Affiliation(s)
- Pengfei Wang
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People’s Republic of China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, People’s Republic of China
| | - Junhua Zhang
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, People’s Republic of China
| | - Chun-Yang Luan
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People’s Republic of China
| | - Mark Um
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People’s Republic of China
| | - Ye Wang
- Department of Electrical and Computer Engineering, Duke University, Durham, NC 27708, USA
| | - Mu Qiao
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People’s Republic of China
| | - Tian Xie
- Kavli Nanoscience Institute and Thomas J. Watson Sr., Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
| | - Jing-Ning Zhang
- Beijing Academy of Quantum Information Sciences, Beijing 100193, People’s Republic of China
| | - Adán Cabello
- Departamento de Física Aplicada II, Universidad de Sevilla, E-41012 Sevilla, Spain
- Instituto Carlos I de Física Teórica y Computacional, Universidad de Sevilla, E-41012 Sevilla, Spain
| | - Kihwan Kim
- State Key Laboratory of Low Dimensional Quantum Physics, Department of Physics, Tsinghua University, Beijing 100084, People’s Republic of China
- Beijing Academy of Quantum Information Sciences, Beijing 100193, People’s Republic of China
- Frontier Science Center for Quantum Information, Beijing 100084, People’s Republic of China
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8
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Milne AR, Hempel C, Li L, Edmunds CL, Slatyer HJ, Ball H, Hush MR, Biercuk MJ. Quantum Oscillator Noise Spectroscopy via Displaced Cat States. PHYSICAL REVIEW LETTERS 2021; 126:250506. [PMID: 34241523 DOI: 10.1103/physrevlett.126.250506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 04/21/2021] [Indexed: 06/13/2023]
Abstract
Quantum harmonic oscillators are central to many modern quantum technologies. We introduce a method to determine the frequency noise spectrum of oscillator modes through coupling them to a qubit with continuously driven qubit-state-dependent displacements. We reconstruct the noise spectrum using a series of different drive phase and amplitude modulation patterns in conjunction with a data-fusion routine based on convex optimization. We apply the technique to the identification of intrinsic noise in the motional frequency of a single trapped ion with sensitivity to fluctuations at the sub-Hz level in a spectral range from quasi-dc up to 50 kHz.
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Affiliation(s)
- Alistair R Milne
- ARC Centre of Excellence for Engineered Quantum Systems, The University of Sydney, School of Physics, New South Wales 2006, Australia
| | - Cornelius Hempel
- ARC Centre of Excellence for Engineered Quantum Systems, The University of Sydney, School of Physics, New South Wales 2006, Australia
| | - Li Li
- Q-CTRL Pty Ltd, Sydney, New South Wales 2006, Australia
| | - Claire L Edmunds
- ARC Centre of Excellence for Engineered Quantum Systems, The University of Sydney, School of Physics, New South Wales 2006, Australia
| | | | - Harrison Ball
- Q-CTRL Pty Ltd, Sydney, New South Wales 2006, Australia
| | | | - Michael J Biercuk
- ARC Centre of Excellence for Engineered Quantum Systems, The University of Sydney, School of Physics, New South Wales 2006, Australia
- Q-CTRL Pty Ltd, Sydney, New South Wales 2006, Australia
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9
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Shinjo A, Baba M, Higashiyama K, Saito R, Mukaiyama T. Three-Dimensional Matter-Wave Interferometry of a Trapped Single Ion. PHYSICAL REVIEW LETTERS 2021; 126:153604. [PMID: 33929227 DOI: 10.1103/physrevlett.126.153604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 02/02/2021] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
We report on a demonstration of Ramsey interferometry by three-dimensional motion with a trapped ^{171}Yb^{+} ion. We applied a momentum kick to the ion in a direction diagonal to the trap axes to initiate three-dimensional motion using a mode-locked pulse laser. The interference signal was analyzed theoretically to demonstrate three-dimensional matter-wave interference. This work paves the way to realizing matter-wave interferometry using trapped ions.
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Affiliation(s)
- Ami Shinjo
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Masato Baba
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Koya Higashiyama
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
| | - Ryoichi Saito
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
- Quantum Information and Quantum Biology Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka 560-8531, Japan
| | - Takashi Mukaiyama
- Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, Osaka 560-8531, Japan
- Quantum Information and Quantum Biology Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Osaka 560-8531, Japan
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10
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Cai ML, Liu ZD, Zhao WD, Wu YK, Mei QX, Jiang Y, He L, Zhang X, Zhou ZC, Duan LM. Observation of a quantum phase transition in the quantum Rabi model with a single trapped ion. Nat Commun 2021; 12:1126. [PMID: 33602942 PMCID: PMC7893029 DOI: 10.1038/s41467-021-21425-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 01/22/2021] [Indexed: 11/30/2022] Open
Abstract
Quantum phase transitions (QPTs) are usually associated with many-body systems in the thermodynamic limit when their ground states show abrupt changes at zero temperature with variation of a parameter in the Hamiltonian. Recently it has been realized that a QPT can also occur in a system composed of only a two-level atom and a single-mode bosonic field, described by the quantum Rabi model (QRM). Here we report an experimental demonstration of a QPT in the QRM using a 171Yb+ ion in a Paul trap. We measure the spin-up state population and the average phonon number of the ion as two order parameters and observe clear evidence of the phase transition via adiabatic tuning of the coupling between the ion and its spatial motion. An experimental probe of the phase transition in a fundamental quantum optics model without imposing the thermodynamic limit opens up a window for controlled study of QPTs and quantum critical phenomena. Quantum phase transition occurs in many-body systems with abrupt changes in the ground state around zero temperature. Here the authors report signatures of quantum phase transition in single trapped ion that can be described using quantum Rabi model.
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Affiliation(s)
- M-L Cai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Z-D Liu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - W-D Zhao
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Y-K Wu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Q-X Mei
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - Y Jiang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - L He
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China
| | - X Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China.,Department of Physics, Renmin University, Beijing, PR China
| | - Z-C Zhou
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China.,Beijing Academy of Quantum Information Sciences, Beijing, PR China
| | - L-M Duan
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, PR China.
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11
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Qiao M, Wang Y, Cai Z, Du B, Wang P, Luan C, Chen W, Noh HR, Kim K. Double-Electromagnetically-Induced-Transparency Ground-State Cooling of Stationary Two-Dimensional Ion Crystals. PHYSICAL REVIEW LETTERS 2021; 126:023604. [PMID: 33512231 DOI: 10.1103/physrevlett.126.023604] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 12/21/2020] [Indexed: 06/12/2023]
Abstract
We theoretically and experimentally investigate double-electromagnetically-induced transparency (double-EIT) cooling of two-dimensional ion crystals confined in a Paul trap. The double-EIT ground-state cooling is observed for ^{171}Yb^{+} ions with a clock state, for which EIT cooling has not been realized like many other ions with a simple Λ scheme. A cooling rate of n[over ¯][over ˙]=34(±1.8) ms^{-1} and a cooling limit of n[over ¯]=0.06(±0.059) are observed for a single ion. The measured cooling rate and limit are consistent with theoretical predictions. We apply double-EIT cooling to the transverse modes of two-dimensional (2D) crystals with up to 12 ions. In our 2D crystals, the micromotion and the transverse mode directions are perpendicular, which makes them decoupled. Therefore, the cooling on transverse modes is not disturbed by micromotion, which is confirmed in our experiment. For the center of mass mode of a 12-ion crystal, we observe a cooling rate and a cooling limit that are consistent with those of a single ion, including heating rates proportional to the number of ions. This method can be extended to other hyperfine qubits, and near ground-state cooling of stationary 2D crystals with large numbers of ions may advance the field of quantum information sciences.
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Affiliation(s)
- Mu Qiao
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Ye Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Zhengyang Cai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Botao Du
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
- Department of Physics and Astronomy, Purdue University, West Lafayette, Indiana 47907, USA
| | - Pengfei Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Chunyang Luan
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Wentao Chen
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Heung-Ryoul Noh
- Department of Physics, Chonnam National University, Gwangju 61186, Korea
| | - Kihwan Kim
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
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12
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Wang Y, Crain S, Fang C, Zhang B, Huang S, Liang Q, Leung PH, Brown KR, Kim J. High-Fidelity Two-Qubit Gates Using a Microelectromechanical-System-Based Beam Steering System for Individual Qubit Addressing. PHYSICAL REVIEW LETTERS 2020; 125:150505. [PMID: 33095613 DOI: 10.1103/physrevlett.125.150505] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
In a large scale trapped atomic ion quantum computer, high-fidelity two-qubit gates need to be extended over all qubits with individual control. We realize and characterize high-fidelity two-qubit gates in a system with up to four ions using radial modes. The ions are individually addressed by two tightly focused beams steered using microelectromechanical system mirrors. We deduce a gate fidelity of 99.49(7)% in a two-ion chain and 99.30(6)% in a four-ion chain by applying a sequence of up to 21 two-qubit gates and measuring the final state fidelity. We characterize the residual errors and discuss methods to further improve the gate fidelity towards values that are compatible with fault-tolerant quantum computation.
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Affiliation(s)
- Ye Wang
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Stephen Crain
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Chao Fang
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Bichen Zhang
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Shilin Huang
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Qiyao Liang
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
| | - Pak Hong Leung
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
| | - Kenneth R Brown
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
| | - Jungsang Kim
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
- IonQ, Inc., College Park, Maryland 20740, USA
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13
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Feng L, Tan WL, De A, Menon A, Chu A, Pagano G, Monroe C. Efficient Ground-State Cooling of Large Trapped-Ion Chains with an Electromagnetically-Induced-Transparency Tripod Scheme. PHYSICAL REVIEW LETTERS 2020; 125:053001. [PMID: 32794882 DOI: 10.1103/physrevlett.125.053001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 06/12/2020] [Indexed: 06/11/2023]
Abstract
We report the electromagnetically-induced-transparency (EIT) cooling of a large trapped ^{171}Yb^{+} ion chain to the quantum ground state. Unlike conventional EIT cooling, we engage a four-level tripod structure and achieve fast sub-Doppler cooling over all motional modes. We observe simultaneous ground-state cooling across the complete transverse mode spectrum of up to 40 ions, occupying a bandwidth of over 3 MHz. The cooling time is observed to be less than 300 μs, independent of the number of ions. Such efficient cooling across the entire spectrum is essential for high-fidelity quantum operations using trapped ion crystals for quantum simulators or quantum computers.
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Affiliation(s)
- L Feng
- Joint Quantum Institute, Center for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - W L Tan
- Joint Quantum Institute, Center for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - A De
- Joint Quantum Institute, Center for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - A Menon
- Joint Quantum Institute, Center for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - A Chu
- Joint Quantum Institute, Center for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - G Pagano
- Joint Quantum Institute, Center for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
- Department of Physics and Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, USA
| | - C Monroe
- Joint Quantum Institute, Center for Quantum Information and Computer Science, and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
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14
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Gan HCJ, Maslennikov G, Tseng KW, Nguyen C, Matsukevich D. Hybrid Quantum Computing with Conditional Beam Splitter Gate in Trapped Ion System. PHYSICAL REVIEW LETTERS 2020; 124:170502. [PMID: 32412255 DOI: 10.1103/physrevlett.124.170502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2019] [Accepted: 03/25/2020] [Indexed: 06/11/2023]
Abstract
The hybrid approach to quantum computation simultaneously utilizes both discrete and continuous variables, which offers the advantage of higher density encoding and processing powers for the same physical resources. Trapped ions, with discrete internal states and motional modes that can be described by continuous variables in an infinite-dimensional Hilbert space, offer a natural platform for this approach. A nonlinear gate for universal quantum computing can be implemented with the conditional beam splitter Hamiltonian |e⟩⟨e|(a[over ^]^{†}b[over ^]+a[over ^]b[over ^]^{†}) that swaps the quantum states of two motional modes, depending on the ion's internal state. We realize such a gate and demonstrate its applications for quantum state overlap measurements, single-shot parity measurement, and generation of NOON states.
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Affiliation(s)
- H C J Gan
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Gleb Maslennikov
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Ko-Wei Tseng
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Chihuan Nguyen
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Dzmitry Matsukevich
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551 Singapore, Singapore
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15
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Lešundák A, Pham TM, Čížek M, Obšil P, Slodička L, Číp O. Optical frequency analysis on dark state of a single trapped ion. OPTICS EXPRESS 2020; 28:13091-13103. [PMID: 32403790 DOI: 10.1364/oe.389411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/24/2020] [Indexed: 06/11/2023]
Abstract
We demonstrate an optical frequency analysis method using the Fourier transform of detection times of fluorescence photons emitted from a single trapped 40Ca+ ion. The response of the detected photon rate to the relative laser frequency deviations is recorded within the slope of a dark resonance formed in the lambda-type energy level scheme corresponding to two optical dipole transitions. This approach enhances the sensitivity to the small frequency deviations and does so with reciprocal dependence on the fluorescence rate. The employed lasers are phase locked to an optical frequency comb, which allows for precise calibration of optical frequency analysis by deterministic modulation of the analyzed laser beam with respect to the reference beam. The attainable high signal-to-noise ratios of up to a MHz range of modulation deviations and up to a hundred kHz modulation frequencies promise the applicability of the presented results in a broad range of optical spectroscopic applications.
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16
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Chou CW, Collopy AL, Kurz C, Lin Y, Harding ME, Plessow PN, Fortier T, Diddams S, Leibfried D, Leibrandt DR. Frequency-comb spectroscopy on pure quantum states of a single molecular ion. Science 2020; 367:1458-1461. [PMID: 32217722 PMCID: PMC10652508 DOI: 10.1126/science.aba3628] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 03/04/2020] [Indexed: 01/21/2023]
Abstract
Spectroscopy is a powerful tool for studying molecules and is commonly performed on large thermal molecular ensembles that are perturbed by motional shifts and interactions with the environment and one another, resulting in convoluted spectra and limited resolution. Here, we use quantum-logic techniques to prepare a trapped molecular ion in a single quantum state, drive terahertz rotational transitions with an optical frequency comb, and read out the final state nondestructively, leaving the molecule ready for further manipulation. We can resolve rotational transitions to 11 significant digits and derive the rotational constant of 40CaH+ to be B R = 142 501 777.9(1.7) kilohertz. Our approach is suited for a wide range of molecular ions, including polyatomics and species relevant for tests of fundamental physics, chemistry, and astrophysics.
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Affiliation(s)
- C W Chou
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA.
| | - A L Collopy
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - C Kurz
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA
| | - Y Lin
- CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics, University of Science and Technology of China, Hefei 230026, China
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA
- Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China
- Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei 230026, China
| | - M E Harding
- Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe, Germany
| | - P N Plessow
- Institute of Catalysis Research and Technology, Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe, Germany
| | - T Fortier
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - S Diddams
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - D Leibfried
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado, Boulder, CO 80309, USA
| | - D R Leibrandt
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado, Boulder, CO 80309, USA
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17
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Stern L, Stone JR, Kang S, Cole DC, Suh MG, Fredrick C, Newman Z, Vahala K, Kitching J, Diddams SA, Papp SB. Direct Kerr frequency comb atomic spectroscopy and stabilization. SCIENCE ADVANCES 2020; 6:eaax6230. [PMID: 32158936 PMCID: PMC7048413 DOI: 10.1126/sciadv.aax6230] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 12/05/2019] [Indexed: 05/19/2023]
Abstract
Microresonator-based soliton frequency combs, microcombs, have recently emerged to offer low-noise, photonic-chip sources for applications, spanning from timekeeping to optical-frequency synthesis and ranging. Broad optical bandwidth, brightness, coherence, and frequency stability have made frequency combs important to directly probe atoms and molecules, especially in trace gas detection, multiphoton light-atom interactions, and spectroscopy in the extreme ultraviolet. Here, we explore direct microcomb atomic spectroscopy, using a cascaded, two-photon 1529-nm atomic transition in a rubidium micromachined cell. Fine and simultaneous repetition rate and carrier-envelope offset frequency control of the soliton enables direct sub-Doppler and hyperfine spectroscopy. Moreover, the entire set of microcomb modes are stabilized to this atomic transition, yielding absolute optical-frequency fluctuations at the kilohertz level over a few seconds and <1-MHz day-to-day accuracy. Our work demonstrates direct atomic spectroscopy with Kerr microcombs and provides an atomic-stabilized microcomb laser source, operating across the telecom band for sensing, dimensional metrology, and communication.
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Affiliation(s)
- Liron Stern
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
- Corresponding author. (L.S.); (S.B.P)
| | - Jordan R. Stone
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Songbai Kang
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Daniel C. Cole
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Myoung-Gyun Suh
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
| | - Connor Fredrick
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Zachary Newman
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Kerry Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, CA 91125, USA
| | - John Kitching
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
| | - Scott A. Diddams
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
| | - Scott B. Papp
- Time and Frequency Division, National Institute for Standards and Technology, Boulder, CO 80305, USA
- Department of Physics, University of Colorado Boulder, Boulder, CO 80309, USA
- Corresponding author. (L.S.); (S.B.P)
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18
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Wright K, Beck KM, Debnath S, Amini JM, Nam Y, Grzesiak N, Chen JS, Pisenti NC, Chmielewski M, Collins C, Hudek KM, Mizrahi J, Wong-Campos JD, Allen S, Apisdorf J, Solomon P, Williams M, Ducore AM, Blinov A, Kreikemeier SM, Chaplin V, Keesan M, Monroe C, Kim J. Benchmarking an 11-qubit quantum computer. Nat Commun 2019; 10:5464. [PMID: 31784527 PMCID: PMC6884641 DOI: 10.1038/s41467-019-13534-2] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 11/13/2019] [Indexed: 11/23/2022] Open
Abstract
The field of quantum computing has grown from concept to demonstration devices over the past 20 years. Universal quantum computing offers efficiency in approaching problems of scientific and commercial interest, such as factoring large numbers, searching databases, simulating intractable models from quantum physics, and optimizing complex cost functions. Here, we present an 11-qubit fully-connected, programmable quantum computer in a trapped ion system composed of 13 171Yb+ ions. We demonstrate average single-qubit gate fidelities of 99.5\documentclass[12pt]{minimal}
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\begin{document}$$\%$$\end{document}%, respectively. These algorithms serve as excellent benchmarks for any type of quantum hardware, and show that our system outperforms all other currently available hardware. The growing complexity of quantum computing devices makes presents challenges for benchmarking their performance as previous, exhaustive approaches become infeasible. Here the authors characterise the quality of their 11-qubit device by successfully computing two quantum algorithms.
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Affiliation(s)
- K Wright
- IonQ, Inc., College Park, MD, 20740, USA.
| | - K M Beck
- IonQ, Inc., College Park, MD, 20740, USA
| | - S Debnath
- IonQ, Inc., College Park, MD, 20740, USA
| | - J M Amini
- IonQ, Inc., College Park, MD, 20740, USA
| | - Y Nam
- IonQ, Inc., College Park, MD, 20740, USA
| | - N Grzesiak
- IonQ, Inc., College Park, MD, 20740, USA
| | - J-S Chen
- IonQ, Inc., College Park, MD, 20740, USA
| | | | - M Chmielewski
- IonQ, Inc., College Park, MD, 20740, USA.,Joint Quantum Institute and Department of Physics, University of Maryland, College Park, MD, 20742, USA
| | - C Collins
- IonQ, Inc., College Park, MD, 20740, USA
| | - K M Hudek
- IonQ, Inc., College Park, MD, 20740, USA
| | - J Mizrahi
- IonQ, Inc., College Park, MD, 20740, USA
| | | | - S Allen
- IonQ, Inc., College Park, MD, 20740, USA
| | - J Apisdorf
- IonQ, Inc., College Park, MD, 20740, USA
| | - P Solomon
- IonQ, Inc., College Park, MD, 20740, USA
| | - M Williams
- IonQ, Inc., College Park, MD, 20740, USA
| | - A M Ducore
- IonQ, Inc., College Park, MD, 20740, USA
| | - A Blinov
- IonQ, Inc., College Park, MD, 20740, USA
| | | | - V Chaplin
- IonQ, Inc., College Park, MD, 20740, USA
| | - M Keesan
- IonQ, Inc., College Park, MD, 20740, USA
| | - C Monroe
- IonQ, Inc., College Park, MD, 20740, USA.,Joint Quantum Institute and Department of Physics, University of Maryland, College Park, MD, 20742, USA
| | - J Kim
- IonQ, Inc., College Park, MD, 20740, USA.,Department of Electrical and Computer Engineering, Duke University, Durham, NC, 27708, USA
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19
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Lu Y, Zhang S, Zhang K, Chen W, Shen Y, Zhang J, Zhang JN, Kim K. Global entangling gates on arbitrary ion qubits. Nature 2019; 572:363-367. [PMID: 31341282 DOI: 10.1038/s41586-019-1428-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/10/2019] [Indexed: 11/09/2022]
Abstract
Quantum computers can efficiently solve classically intractable problems, such as the factorization of a large number1 and the simulation of quantum many-body systems2,3. Universal quantum computation can be simplified by decomposing circuits into single- and two-qubit entangling gates4, but such decomposition is not necessarily efficient. It has been suggested that polynomial or exponential speedups can be obtained with global N-qubit (N greater than two) entangling gates5-9. Such global gates involve all-to-all connectivity, which emerges among trapped-ion qubits when using laser-driven collective motional modes10-14, and have been implemented for a single motional mode15,16. However, the single-mode approach is difficult to scale up because isolating single modes becomes challenging as the number of ions increases in a single crystal, and multi-mode schemes are scalable17,18 but limited to pairwise gates19-23. Here we propose and implement a scalable scheme for realizing global entangling gates on multiple 171Yb+ ion qubits by coupling to multiple motional modes through modulated laser fields. Because such global gates require decoupling multiple modes and balancing all pairwise coupling strengths during the gate, we develop a system with fully independent control capability on each ion14. To demonstrate the usefulness and flexibility of these global gates, we generate a Greenberger-Horne-Zeilinger state with up to four qubits using a single global operation. Our approach realizes global entangling gates as scalable building blocks for universal quantum computation, motivating future research in scalable global methods for quantum information processing.
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Affiliation(s)
- Yao Lu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China.
| | - Shuaining Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China
| | - Kuan Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China.,MOE Key Laboratory of Fundamental Physical Quantities Measurement & Hubei Key Laboratory of Gravitation and Quantum Physics, PGMF and School of Physics, Huazhong University of Science and Technology, Wuhan, China
| | - Wentao Chen
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China
| | - Yangchao Shen
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China
| | - Jialiang Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China
| | - Jing-Ning Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China
| | - Kihwan Kim
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, China.
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20
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Paschke AG, Zarantonello G, Hahn H, Lang T, Manzoni C, Marangoni M, Cerullo G, Morgner U, Ospelkaus C. Versatile Control of ^{9}Be^{+} Ions Using a Spectrally Tailored UV Frequency Comb. PHYSICAL REVIEW LETTERS 2019; 122:123606. [PMID: 30978050 DOI: 10.1103/physrevlett.122.123606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Indexed: 06/09/2023]
Abstract
We demonstrate quantum control of ^{9}Be^{+} ions directly implemented by an optical frequency comb. Based on numerical simulations of the relevant processes in ^{9}Be^{+} for different magnetic field regimes, we demonstrate a wide applicability when controlling the comb's spectral properties. We introduce a novel technique for the selective and efficient generation of a spectrally tailored narrow-bandwidth optical frequency comb near 313 nm. We experimentally demonstrate internal state control and internal-motional state coupling of ^{9}Be^{+} ions implemented by stimulated-Raman manipulation using a spectrally optimized optical frequency comb. Our pulsed laser approach is a key enabling step for the implementation of quantum logic and quantum information experiments in Penning traps.
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Affiliation(s)
- A-G Paschke
- Institute of Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - G Zarantonello
- Institute of Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - H Hahn
- Institute of Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
| | - T Lang
- Institute of Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
| | - C Manzoni
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, Milano, 20133, Italy
| | - M Marangoni
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, Milano, 20133, Italy
| | - G Cerullo
- IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, Milano, 20133, Italy
| | - U Morgner
- Institute of Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
| | - C Ospelkaus
- Institute of Quantum Optics, Leibniz Universität Hannover, Welfengarten 1, 30167 Hannover, Germany
- Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116 Braunschweig, Germany
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21
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Maslennikov G, Ding S, Hablützel R, Gan J, Roulet A, Nimmrichter S, Dai J, Scarani V, Matsukevich D. Quantum absorption refrigerator with trapped ions. Nat Commun 2019; 10:202. [PMID: 30643131 PMCID: PMC6331551 DOI: 10.1038/s41467-018-08090-0] [Citation(s) in RCA: 50] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 12/07/2018] [Indexed: 11/09/2022] Open
Abstract
In recent years substantial efforts have been expended in extending thermodynamics to single quantum systems. Quantum effects have emerged as a resource that can improve the performance of heat machines. However in the fully quantum regime their implementation still remains a challenge. Here, we report an experimental realization of a quantum absorption refrigerator in a system of three trapped ions, with three of its normal modes of motion coupled by a trilinear Hamiltonian such that heat transfer between two modes refrigerates the third. We investigate the dynamics and steady-state properties of the refrigerator and compare its cooling capability when only thermal states are involved to the case when squeezing is employed as a quantum resource. We also study the performance of such a refrigerator in the single shot regime made possible by coherence and demonstrate cooling below both the steady-state energy and a benchmark set by classical thermodynamics.
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Affiliation(s)
- Gleb Maslennikov
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore
| | - Shiqian Ding
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore.,JILA, National Institute of Standards and Technology and University of Colorado, and Department of Physics, University of Colorado, Boulder, CO, 80309, USA
| | - Roland Hablützel
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore
| | - Jaren Gan
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore
| | - Alexandre Roulet
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore
| | - Stefan Nimmrichter
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore
| | - Jibo Dai
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore
| | - Valerio Scarani
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore.,Department of Physics, National University of Singapore, 2 Science Dr 3, Singapore, 117551, Singapore
| | - Dzmitry Matsukevich
- Centre for Quantum Technologies, National University of Singapore, 3 Science Dr 2, Singapore, 117543, Singapore. .,Department of Physics, National University of Singapore, 2 Science Dr 3, Singapore, 117551, Singapore.
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22
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Zhang J, Um M, Lv D, Zhang JN, Duan LM, Kim K. NOON States of Nine Quantized Vibrations in Two Radial Modes of a Trapped Ion. PHYSICAL REVIEW LETTERS 2018; 121:160502. [PMID: 30387619 DOI: 10.1103/physrevlett.121.160502] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Revised: 07/25/2018] [Indexed: 06/08/2023]
Abstract
We develop a deterministic method to generate and verify arbitrarily high NOON states of quantized vibrations (phonons), through the coupling to the internal state. We experimentally create the entangled states up to N=9 phonons in two vibrational modes of a single trapped ^{171}Yb^{+} ion. We observe an increasing phase sensitivity of the generated NOON state as the number of phonons N increases and obtain the fidelity from the contrast of the phase interference and the population of the phonon states through the two-mode projective measurement, which are significantly above the classical bound. We also measure the quantum Fisher information of the generated state and observe Heisenberg scaling in the lower bounds of phase sensitivity as N increases. Our scheme is generic and applicable to other photonic or phononic systems such as circuit QED systems or nanomechanical oscillators, which have Jaynes-Cummings-type of interactions.
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Affiliation(s)
- Junhua Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, People's Republic of China
- Shenzhen Institute for Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
- Department of Physics, Southern University of Science and Technology, Shenzhen, 518055, People's Republic of China
| | - Mark Um
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Dingshun Lv
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Jing-Ning Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Lu-Ming Duan
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, People's Republic of China
| | - Kihwan Kim
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, People's Republic of China
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23
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Ding S, Maslennikov G, Hablützel R, Matsukevich D. Quantum Simulation with a Trilinear Hamiltonian. PHYSICAL REVIEW LETTERS 2018; 121:130502. [PMID: 30312083 DOI: 10.1103/physrevlett.121.130502] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/12/2018] [Indexed: 06/08/2023]
Abstract
Interaction among harmonic oscillators described by a trilinear Hamiltonian ℏξ(a^{†}bc+ab^{†}c^{†}) is one of the most fundamental models in quantum optics. By employing the anharmonicity of the Coulomb potential in a linear trapped three-ion crystal, we experimentally implement it among three normal modes of motion in the strong-coupling regime, where the coupling strength is much larger than the decoherence rate of the ion motion. We use it to simulate the interaction of an atom and light as described by the Tavis-Cummings model and the process of nondegenerate parametric down-conversion in the regime of a depleted pump.
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Affiliation(s)
- Shiqian Ding
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543, Singapore
| | - Gleb Maslennikov
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543, Singapore
| | - Roland Hablützel
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543, Singapore
| | - Dzmitry Matsukevich
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551, Singapore
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24
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Solaro C, Meyer S, Fisher K, DePalatis MV, Drewsen M. Direct Frequency-Comb-Driven Raman Transitions in the Terahertz Range. PHYSICAL REVIEW LETTERS 2018; 120:253601. [PMID: 29979052 DOI: 10.1103/physrevlett.120.253601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Indexed: 06/08/2023]
Abstract
We demonstrate the use of a femtosecond frequency comb to coherently drive stimulated Raman transitions between terahertz-spaced atomic energy levels. More specifically, we address the 3d ^{2}D_{3/2} and 3d ^{2}D_{5/2} fine structure levels of a single trapped ^{40}Ca^{+} ion and spectroscopically resolve the transition frequency to be ν_{D}=1,819,599,021,534±8 Hz. The achieved accuracy is nearly a factor of five better than the previous best Raman spectroscopy, and is currently limited by the stability of our atomic clock reference. Furthermore, the population dynamics of frequency-comb-driven Raman transitions can be fully predicted from the spectral properties of the frequency comb, and Rabi oscillations with a contrast of 99.3(6)% and millisecond coherence time have been achieved. Importantly, the technique can be easily generalized to transitions in the sub-kHz to tens of THz range and should be applicable for driving, e.g., spin-resolved rovibrational transitions in molecules and hyperfine transitions in highly charged ions.
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Affiliation(s)
- C Solaro
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - S Meyer
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - K Fisher
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M V DePalatis
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
| | - M Drewsen
- Department of Physics and Astronomy, Aarhus University, DK-8000 Aarhus C, Denmark
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25
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Observation of a many-body dynamical phase transition with a 53-qubit quantum simulator. Nature 2018; 551:601-604. [PMID: 29189781 DOI: 10.1038/nature24654] [Citation(s) in RCA: 197] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/20/2017] [Indexed: 12/23/2022]
Abstract
A quantum simulator is a type of quantum computer that controls the interactions between quantum bits (or qubits) in a way that can be mapped to certain quantum many-body problems. As it becomes possible to exert more control over larger numbers of qubits, such simulators will be able to tackle a wider range of problems, such as materials design and molecular modelling, with the ultimate limit being a universal quantum computer that can solve general classes of hard problems. Here we use a quantum simulator composed of up to 53 qubits to study non-equilibrium dynamics in the transverse-field Ising model with long-range interactions. We observe a dynamical phase transition after a sudden change of the Hamiltonian, in a regime in which conventional statistical mechanics does not apply. The qubits are represented by the spins of trapped ions, which can be prepared in various initial pure states. We apply a global long-range Ising interaction with controllable strength and range, and measure each individual qubit with an efficiency of nearly 99 per cent. Such high efficiency means that arbitrary many-body correlations between qubits can be measured in a single shot, enabling the dynamical phase transition to be probed directly and revealing computationally intractable features that rely on the long-range interactions and high connectivity between qubits.
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26
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Malinovskaya SA, Liu G. Adiabatic Passage Control Methods for Ultracold Alkali Atoms and Molecules via Chirped Laser Pulses and Optical Frequency Combs. ADVANCES IN QUANTUM CHEMISTRY 2018. [DOI: 10.1016/bs.aiq.2018.02.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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27
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Hess PW, Becker P, Kaplan HB, Kyprianidis A, Lee AC, Neyenhuis B, Pagano G, Richerme P, Senko C, Smith J, Tan WL, Zhang J, Monroe C. Non-thermalization in trapped atomic ion spin chains. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2017; 375:rsta.2017.0107. [PMID: 29084886 PMCID: PMC5665787 DOI: 10.1098/rsta.2017.0107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/27/2017] [Indexed: 05/27/2023]
Abstract
Linear arrays of trapped and laser-cooled atomic ions are a versatile platform for studying strongly interacting many-body quantum systems. Effective spins are encoded in long-lived electronic levels of each ion and made to interact through laser-mediated optical dipole forces. The advantages of experiments with cold trapped ions, including high spatio-temporal resolution, decoupling from the external environment and control over the system Hamiltonian, are used to measure quantum effects not always accessible in natural condensed matter samples. In this review, we highlight recent work using trapped ions to explore a variety of non-ergodic phenomena in long-range interacting spin models, effects that are heralded by the memory of out-of-equilibrium initial conditions. We observe long-lived memory in static magnetizations for quenched many-body localization and prethermalization, while memory is preserved in the periodic oscillations of a driven discrete time crystal state.This article is part of the themed issue 'Breakdown of ergodicity in quantum systems: from solids to synthetic matter'.
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Affiliation(s)
- P W Hess
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - P Becker
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - H B Kaplan
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - A Kyprianidis
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - A C Lee
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - B Neyenhuis
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - G Pagano
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - P Richerme
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - C Senko
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - J Smith
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - W L Tan
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - J Zhang
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
| | - C Monroe
- Joint Quantum Institute, Department of Physics, University of Maryland and National Institute of Standards and Technology, College Park, MD 20742, USA
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28
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Complete 3-Qubit Grover search on a programmable quantum computer. Nat Commun 2017; 8:1918. [PMID: 29203858 PMCID: PMC5715115 DOI: 10.1038/s41467-017-01904-7] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 10/25/2017] [Indexed: 11/17/2022] Open
Abstract
The Grover quantum search algorithm is a hallmark application of a quantum computer with a well-known speedup over classical searches of an unsorted database. Here, we report results for a complete three-qubit Grover search algorithm using the scalable quantum computing technology of trapped atomic ions, with better-than-classical performance. Two methods of state marking are used for the oracles: a phase-flip method employed by other experimental demonstrations, and a Boolean method requiring an ancilla qubit that is directly equivalent to the state marking scheme required to perform a classical search. We also report the deterministic implementation of a Toffoli-4 gate, which is used along with Toffoli-3 gates to construct the algorithms; these gates have process fidelities of 70.5% and 89.6%, respectively. Grover’s algorithm provides a quantum speedup when searching through an unsorted database. Here, the authors perform it on 3 qubits using trapped ions, demonstrating two methods for marking the correct result in the algorithm’s oracle and providing data for searches yielding 1 or 2 solutions.
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29
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Ding S, Maslennikov G, Hablützel R, Matsukevich D. Cross-Kerr Nonlinearity for Phonon Counting. PHYSICAL REVIEW LETTERS 2017; 119:193602. [PMID: 29219528 DOI: 10.1103/physrevlett.119.193602] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Indexed: 06/07/2023]
Abstract
State measurement of a quantum harmonic oscillator is essential in quantum optics and quantum information processing. In a system of trapped ions, we experimentally demonstrate the projective measurement of the state of the ions' motional mode via an effective cross-Kerr coupling to another motional mode. This coupling is induced by the intrinsic nonlinearity of the Coulomb interaction between the ions. We spectroscopically resolve the frequency shift of the motional sideband of the first mode due to the presence of single phonons in the second mode and use it to reconstruct the phonon number distribution of the second mode.
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Affiliation(s)
- Shiqian Ding
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Gleb Maslennikov
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Roland Hablützel
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Dzmitry Matsukevich
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551 Singapore, Singapore
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30
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Ding S, Maslennikov G, Hablützel R, Loh H, Matsukevich D. Quantum Parametric Oscillator with Trapped Ions. PHYSICAL REVIEW LETTERS 2017; 119:150404. [PMID: 29077472 DOI: 10.1103/physrevlett.119.150404] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Indexed: 06/07/2023]
Abstract
A strong nonlinear coupling between harmonic oscillators is highly desirable for quantum information processing and quantum simulation, but is difficult to achieve in many physical systems. Here, we exploit the Coulomb interaction between two trapped ions to achieve strong nonlinear coupling between normal modes of motion at the single-phonon level. We experimentally demonstrate phonon up- and down-conversion and apply this coupling to directly measure the parity and Wigner functions of the ions' motional states. Our results represent the fully quantum operation of a degenerate parametric oscillator and hold promise for quantum computation schemes that involve continuous variables.
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Affiliation(s)
- Shiqian Ding
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Gleb Maslennikov
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Roland Hablützel
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Huanqian Loh
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Dzmitry Matsukevich
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117551 Singapore, Singapore
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31
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Inlek IV, Crocker C, Lichtman M, Sosnova K, Monroe C. Multispecies Trapped-Ion Node for Quantum Networking. PHYSICAL REVIEW LETTERS 2017; 118:250502. [PMID: 28696766 DOI: 10.1103/physrevlett.118.250502] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Indexed: 06/07/2023]
Abstract
Trapped atomic ions are a leading platform for quantum information networks, with long-lived identical qubit memories that can be locally entangled through their Coulomb interaction and remotely entangled through photonic channels. However, performing both local and remote operations in a single node of a quantum network requires extreme isolation between spectator qubit memories and qubits associated with the photonic interface. We achieve this isolation by cotrapping ^{171}Yb^{+} and ^{138}Ba^{+} qubits. We further demonstrate the ingredients of a scalable ion trap network node with two distinct experiments that consist of entangling the mixed species qubit pair through their collective motion and entangling a ^{138}Ba^{+} qubit with an emitted visible photon.
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Affiliation(s)
- I V Inlek
- Joint Quantum Institute and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - C Crocker
- Joint Quantum Institute and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - M Lichtman
- Joint Quantum Institute and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - K Sosnova
- Joint Quantum Institute and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
| | - C Monroe
- Joint Quantum Institute and Department of Physics, University of Maryland, College Park, Maryland 20742, USA
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32
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Observation of a discrete time crystal. Nature 2017; 543:217-220. [DOI: 10.1038/nature21413] [Citation(s) in RCA: 634] [Impact Index Per Article: 90.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 01/10/2017] [Indexed: 11/08/2022]
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33
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Yoon Oh D, Yang KY, Fredrick C, Ycas G, Diddams SA, Vahala KJ. Coherent ultra-violet to near-infrared generation in silica ridge waveguides. Nat Commun 2017; 8:13922. [PMID: 28067233 PMCID: PMC5227738 DOI: 10.1038/ncomms13922] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 11/11/2016] [Indexed: 11/25/2022] Open
Abstract
Short duration, intense pulses of light can experience dramatic spectral broadening when propagating through lengths of optical fibre. This continuum generation process is caused by a combination of nonlinear optical effects including the formation of dispersive waves. Optical analogues of Cherenkov radiation, these waves allow a pulse to radiate power into a distant spectral region. In this work, efficient and coherent dispersive wave generation of visible to ultraviolet light is demonstrated in silica waveguides on a silicon chip. Unlike fibre broadeners, the arrays provide a wide range of emission wavelength choices on a single, compact chip. This new capability is used to simplify offset frequency measurements of a mode-locked frequency comb. The arrays can also enable mode-locked lasers to attain unprecedented tunable spectral reach for spectroscopy, bioimaging, tomography and metrology. Continuum generation in optical fibres has enabled many applications, like optical frequency combs. Here, Oh et al. demonstrate controlled dispersive-wave generation in on-chip silica waveguides, which could have a similar impact on integrated devices.
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Affiliation(s)
- Dong Yoon Oh
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Ki Youl Yang
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
| | - Connor Fredrick
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Gabriel Ycas
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Scott A Diddams
- Time and Frequency Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
| | - Kerry J Vahala
- T. J. Watson Laboratory of Applied Physics, California Institute of Technology, Pasadena, California 91125, USA
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34
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Demonstration of a small programmable quantum computer with atomic qubits. Nature 2016; 536:63-6. [DOI: 10.1038/nature18648] [Citation(s) in RCA: 435] [Impact Index Per Article: 54.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/01/2016] [Indexed: 11/08/2022]
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35
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Johnson KG, Wong-Campos JD, Restelli A, Landsman KA, Neyenhuis B, Mizrahi J, Monroe C. Active stabilization of ion trap radiofrequency potentials. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:053110. [PMID: 27250395 DOI: 10.1063/1.4948734] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a radiofrequency (rf) Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to be better than 10 Hz or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique could impact the sensitivity of ion trap mass spectrometry and the fidelity of quantum operations in ion trap quantum information applications.
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Affiliation(s)
- K G Johnson
- Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742, USA
| | - J D Wong-Campos
- Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742, USA
| | - A Restelli
- Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742, USA
| | - K A Landsman
- Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742, USA
| | - B Neyenhuis
- Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742, USA
| | - J Mizrahi
- Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742, USA
| | - C Monroe
- Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742, USA
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36
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Abstract
Single-quantum level operations are important tools to manipulate a quantum state. Annihilation or creation of single particles translates a quantum state to another by adding or subtracting a particle, depending on how many are already in the given state. The operations are probabilistic and the success rate has yet been low in their experimental realization. Here we experimentally demonstrate (near) deterministic addition and subtraction of a bosonic particle, in particular a phonon of ionic motion in a harmonic potential. We realize the operations by coupling phonons to an auxiliary two-level system and applying transitionless adiabatic passage. We show handy repetition of the operations on various initial states and demonstrate by the reconstruction of the density matrices that the operations preserve coherences. We observe the transformation of a classical state to a highly non-classical one and a Gaussian state to a non-Gaussian one by applying a sequence of operations deterministically.
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37
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Geng XT, Chun BJ, Seo JH, Seo K, Yoon H, Kim DE, Kim YJ, Kim S. Frequency comb transferred by surface plasmon resonance. Nat Commun 2016; 7:10685. [PMID: 26898307 PMCID: PMC4764863 DOI: 10.1038/ncomms10685] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 01/11/2016] [Indexed: 12/02/2022] Open
Abstract
Frequency combs, millions of narrow-linewidth optical modes referenced to an atomic clock, have shown remarkable potential in time/frequency metrology, atomic/molecular spectroscopy and precision LIDARs. Applications have extended to coherent nonlinear Raman spectroscopy of molecules and quantum metrology for entangled atomic qubits. Frequency combs will create novel possibilities in nano-photonics and plasmonics; however, its interrelation with surface plasmons is unexplored despite the important role that plasmonics plays in nonlinear spectroscopy and quantum optics through the manipulation of light on a subwavelength scale. Here, we demonstrate that a frequency comb can be transformed to a plasmonic comb in plasmonic nanostructures and reverted to the original frequency comb without noticeable degradation of <6.51 × 10−19 in absolute position, 2.92 × 10−19 in stability and 1 Hz in linewidth. The results indicate that the superior performance of a well-defined frequency comb can be applied to nanoplasmonic spectroscopy, quantum metrology and subwavelength photonic circuits. Combining frequency combs and plasmonics promises highly precise timing and frequency standards in nanoscale devices. Here, the authors experimentally transfer a frequency comb to surface plasmons and then return it to its original comb form with little degradation.
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Affiliation(s)
- Xiao Tao Geng
- Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Res. Initiative, Pohang, Gyeongbuk 376-73, South Korea.,Department of Physics, Center for Attosecond Science and Technology (CASTECH), POSTECH, Pohang, Gyeongbuk 376-73, South Korea
| | - Byung Jae Chun
- School of Mechanical and Aerospace Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Ji Hoon Seo
- Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, South Korea
| | - Kwanyong Seo
- Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, South Korea
| | - Hana Yoon
- Energy Storage Department, Korea Institute of Energy Research (KIER), Daejeon 305-343, South Korea
| | - Dong-Eon Kim
- Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Res. Initiative, Pohang, Gyeongbuk 376-73, South Korea.,Department of Physics, Center for Attosecond Science and Technology (CASTECH), POSTECH, Pohang, Gyeongbuk 376-73, South Korea
| | - Young-Jin Kim
- School of Mechanical and Aerospace Engineering, Nanyang Technological University (NTU), 50 Nanyang Avenue, Singapore 639798, Singapore
| | - Seungchul Kim
- Max Planck Center for Attosecond Science, Max Planck POSTECH/KOREA Res. Initiative, Pohang, Gyeongbuk 376-73, South Korea.,Department of Physics, Center for Attosecond Science and Technology (CASTECH), POSTECH, Pohang, Gyeongbuk 376-73, South Korea
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38
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Ding S, Loh H, Hablutzel R, Gao M, Maslennikov G, Matsukevich D. Microwave control of trapped-ion motion assisted by a running optical lattice. PHYSICAL REVIEW LETTERS 2014; 113:073002. [PMID: 25170703 DOI: 10.1103/physrevlett.113.073002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Indexed: 06/03/2023]
Abstract
We experimentally demonstrate microwave control of the motional state of a trapped ion placed in a state-dependent potential generated by a running optical lattice. Both the optical lattice depth and the running lattice frequency provide tunability of the spin-motion coupling strength. The spin-motional coupling is exploited to demonstrate sideband cooling of a ^{171}Yb^{+} ion to the ground state of motion.
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Affiliation(s)
- Shiqian Ding
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Huanqian Loh
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Roland Hablutzel
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Meng Gao
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore and Department of Physics, National University of Singapore, 2 Science Drive 3, 117551 Singapore, Singapore
| | - Gleb Maslennikov
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore
| | - Dzmitry Matsukevich
- Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 Singapore, Singapore and Department of Physics, National University of Singapore, 2 Science Drive 3, 117551 Singapore, Singapore
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39
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Islam R, Campbell WC, Choi T, Clark SM, Conover CWS, Debnath S, Edwards EE, Fields B, Hayes D, Hucul D, Inlek IV, Johnson KG, Korenblit S, Lee A, Lee KW, Manning TA, Matsukevich DN, Mizrahi J, Quraishi Q, Senko C, Smith J, Monroe C. Beat note stabilization of mode-locked lasers for quantum information processing. OPTICS LETTERS 2014; 39:3238-3241. [PMID: 24876022 DOI: 10.1364/ol.39.003238] [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 stabilize a chosen radio frequency beat note between two optical fields derived from the same mode-locked laser pulse train in order to coherently manipulate quantum information. This scheme does not require access or active stabilization of the laser repetition rate. We implement and characterize this external lock, in the context of two-photon stimulated Raman transitions between the hyperfine ground states of trapped 171Yb(+) quantum bits.
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40
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Choi T, Debnath S, Manning TA, Figgatt C, Gong ZX, Duan LM, Monroe C. Optimal quantum control of multimode couplings between trapped ion qubits for scalable entanglement. PHYSICAL REVIEW LETTERS 2014; 112:190502. [PMID: 24877921 DOI: 10.1103/physrevlett.112.190502] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Indexed: 06/03/2023]
Abstract
We demonstrate entangling quantum gates within a chain of five trapped ion qubits by optimally shaping optical fields that couple to multiple collective modes of motion. We individually address qubits with segmented optical pulses to construct multipartite entangled states in a programmable way. This approach enables high-fidelity gates that can be scaled to larger qubit registers for quantum computation and simulation.
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Affiliation(s)
- T Choi
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - S Debnath
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - T A Manning
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - C Figgatt
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - Z-X Gong
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA and Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - L-M Duan
- Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - C Monroe
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
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Richerme P, Senko C, Korenblit S, Smith J, Lee A, Islam R, Campbell WC, Monroe C. Quantum catalysis of magnetic phase transitions in a quantum simulator. PHYSICAL REVIEW LETTERS 2013; 111:100506. [PMID: 25166645 DOI: 10.1103/physrevlett.111.100506] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2013] [Revised: 06/25/2013] [Indexed: 06/03/2023]
Abstract
We control quantum fluctuations to create the ground state magnetic phases of a classical Ising model with a tunable longitudinal magnetic field using a system of 6 to 10 atomic ion spins. Because of the long-range Ising interactions, the various ground state spin configurations are separated by multiple first-order phase transitions, which in our zero temperature system cannot be driven by thermal fluctuations. We instead use a transverse magnetic field as a quantum catalyst to observe the first steps of the complete fractal devil's staircase, which emerges in the thermodynamic limit and can be mapped to a large number of many-body and energy-optimization problems.
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Affiliation(s)
- P Richerme
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - C Senko
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - S Korenblit
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - J Smith
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - A Lee
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - R Islam
- Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
| | - W C Campbell
- Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA
| | - C Monroe
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
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Mizrahi J, Senko C, Neyenhuis B, Johnson KG, Campbell WC, Conover CWS, Monroe C. Ultrafast spin-motion entanglement and interferometry with a single atom. PHYSICAL REVIEW LETTERS 2013; 110:203001. [PMID: 25167401 DOI: 10.1103/physrevlett.110.203001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Indexed: 06/03/2023]
Abstract
We report entanglement of a single atom's hyperfine spin state with its motional state in a time scale of less than 3 ns. We engineer a short train of intense laser pulses to impart a spin-dependent momentum transfer of ± 2 ħk. Using pairs of momentum kicks, we create an atomic interferometer and demonstrate collapse and revival of spin coherence as the motional wave packet is split and recombined. The revival after a pair of kicks occurs only when the second kick is delayed by an integer multiple of the harmonic trap period, a signature of entanglement and disentanglement of the spin with the motion. Such quantum control opens a new regime of ultrafast entanglement in atomic qubits.
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Affiliation(s)
- J Mizrahi
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - C Senko
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - B Neyenhuis
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - K G Johnson
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
| | - W C Campbell
- Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095, USA
| | - C W S Conover
- Physics Department, Colby College, Waterville, Maine 04901, USA
| | - C Monroe
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742, USA
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43
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Hayes D, Clark SM, Debnath S, Hucul D, Inlek IV, Lee KW, Quraishi Q, Monroe C. Coherent error suppression in multiqubit entangling gates. PHYSICAL REVIEW LETTERS 2012; 109:020503. [PMID: 23030141 DOI: 10.1103/physrevlett.109.020503] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2011] [Revised: 04/26/2012] [Indexed: 06/01/2023]
Abstract
We demonstrate a simple pulse shaping technique designed to improve the fidelity of spin-dependent force operations commonly used to implement entangling gates in trapped ion systems. This extension of the Mølmer-Sørensen gate can theoretically suppress the effects of certain frequency and timing errors to any desired order and is demonstrated through Walsh modulation of a two qubit entangling gate on trapped atomic ions. The technique is applicable to any system of qubits coupled through collective harmonic oscillator modes.
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Affiliation(s)
- D Hayes
- Joint Quantum Institute and Department of Physics, University of Maryland, College Park, Maryland 20742, USA.
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Collins TA, Malinovskaya SA. Manipulation of ultracold Rb atoms using a single linearly chirped laser pulse. OPTICS LETTERS 2012; 37:2298-2300. [PMID: 22739887 DOI: 10.1364/ol.37.002298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
At ultracold temperatures, atoms are free from thermal motion, which makes them ideal objects of investigations aiming to advance high-precision spectroscopy, metrology, quantum computation, producing Bose condensates, etc. The quantum state of ultracold atoms may be created and manipulated by making use of quantum control methods employing low-intensity pulses. We theoretically investigate population dynamics of ultracold Rb vapor induced by nanosecond linearly chirped pulses having kW/cm2 beam intensity and show a possibility of controllable population transfer between hyperfine (HpF) levels of 5(2)/S(1/2) state through Raman transitions. Satisfying the one-photon resonance condition with the lowest of the HpF states of 5(2)/P(1/2) or 5(2)/P(3/2) state allows us to enter the adiabatic region of population transfer at very low field intensities, such that corresponding Rabi frequencies are less than or equal to the HpF splitting. This methodology provides a robust way to create a specifically designed superposition state in Rb in the basis of HpF levels and perform state manipulation controllable on the picosecond-to-nanosecond time scale.
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Affiliation(s)
- T A Collins
- Department of Physics, Stevens Institute of Technology, Hoboken, New Jersey 07030, USA
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Campbell WC, Mizrahi J, Quraishi Q, Senko C, Hayes D, Hucul D, Matsukevich DN, Maunz P, Monroe C. Ultrafast gates for single atomic qubits. PHYSICAL REVIEW LETTERS 2010; 105:090502. [PMID: 20868145 DOI: 10.1103/physrevlett.105.090502] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2010] [Indexed: 05/29/2023]
Abstract
We demonstrate single-qubit operations on a trapped atom hyperfine qubit using a single ultrafast pulse from a mode-locked laser. We shape the pulse from the laser and perform a π rotation of the qubit in less than 50 ps with a population transfer exceeding 99% and negligible effects from spontaneous emission or ac Stark shifts. The gate time is significantly shorter than the period of atomic motion in the trap (Ω(Rabi)/ν(trap)>10(4)), demonstrating that this interaction takes place deep within the strong excitation regime.
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Affiliation(s)
- W C Campbell
- Joint Quantum Institute, University of Maryland Department of Physics and National Institute of Standards and Technology, College Park, Maryland 20742 USA.
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