1
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Kang M, Nuomin H, Chowdhury SN, Yuly JL, Sun K, Whitlow J, Valdiviezo J, Zhang Z, Zhang P, Beratan DN, Brown KR. Seeking a quantum advantage with trapped-ion quantum simulations of condensed-phase chemical dynamics. Nat Rev Chem 2024; 8:340-358. [PMID: 38641733 DOI: 10.1038/s41570-024-00595-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/07/2024] [Indexed: 04/21/2024]
Abstract
Simulating the quantum dynamics of molecules in the condensed phase represents a longstanding challenge in chemistry. Trapped-ion quantum systems may serve as a platform for the analog-quantum simulation of chemical dynamics that is beyond the reach of current classical-digital simulation. To identify a 'quantum advantage' for these simulations, performance analysis of both analog-quantum simulation on noisy hardware and classical-digital algorithms is needed. In this Review, we make a comparison between a noisy analog trapped-ion simulator and a few choice classical-digital methods on simulating the dynamics of a model molecular Hamiltonian with linear vibronic coupling. We describe several simple Hamiltonians that are commonly used to model molecular systems, which can be simulated with existing or emerging trapped-ion hardware. These Hamiltonians may serve as stepping stones towards the use of trapped-ion simulators for systems beyond the reach of classical-digital methods. Finally, we identify dynamical regimes in which classical-digital simulations seem to have the weakest performance with respect to analog-quantum simulations. These regimes may provide the lowest hanging fruit to make the most of potential quantum advantages.
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Affiliation(s)
- Mingyu Kang
- Duke Quantum Center, Duke University, Durham, NC, USA.
- Department of Physics, Duke University, Durham, NC, USA.
| | - Hanggai Nuomin
- Department of Chemistry, Duke University, Durham, NC, USA
| | | | - Jonathon L Yuly
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ, USA
| | - Ke Sun
- Duke Quantum Center, Duke University, Durham, NC, USA
- Department of Physics, Duke University, Durham, NC, USA
| | - Jacob Whitlow
- Duke Quantum Center, Duke University, Durham, NC, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
| | - Jesús Valdiviezo
- Kenneth S. Pitzer Theory Center, University of California, Berkeley, CA, USA
- Department of Chemistry, University of California, Berkeley, CA, USA
- Departamento de Ciencias, Sección Química, Pontificia Universidad Católica del Perú, Lima, Peru
| | - Zhendian Zhang
- Department of Chemistry, Duke University, Durham, NC, USA
| | - Peng Zhang
- Department of Chemistry, Duke University, Durham, NC, USA
| | - David N Beratan
- Department of Physics, Duke University, Durham, NC, USA.
- Department of Chemistry, Duke University, Durham, NC, USA.
- Department of Biochemistry, Duke University, Durham, NC, USA.
| | - Kenneth R Brown
- Duke Quantum Center, Duke University, Durham, NC, USA.
- Department of Physics, Duke University, Durham, NC, USA.
- Department of Chemistry, Duke University, Durham, NC, USA.
- Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA.
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2
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Mallweger M, de Oliveira MH, Thomm R, Parke H, Kuk N, Higgins G, Bachelard R, Villas-Boas CJ, Hennrich M. Single-Shot Measurements of Phonon Number States Using the Autler-Townes Effect. PHYSICAL REVIEW LETTERS 2023; 131:223603. [PMID: 38101344 DOI: 10.1103/physrevlett.131.223603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 11/01/2023] [Indexed: 12/17/2023]
Abstract
We present a single-shot method to measure motional states in the number basis. The technique can be applied to systems with at least three nondegenerate energy levels which can be coupled to a linear quantum harmonic oscillator. The method relies on probing an Autler-Townes splitting that arises when a phonon-number changing transition is strongly coupled. We demonstrate the method using a single trapped ion and show that it may be used in a nondemolition fashion to prepare phonon number states. We also show how the Autler-Townes splitting can be used to measure phonon number distributions.
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Affiliation(s)
- Marion Mallweger
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden
| | | | - Robin Thomm
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Harry Parke
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Natalia Kuk
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Gerard Higgins
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden
- Department of Microtechnology and Nanoscience (MC2), Chalmers University of Technology, SE-412 96 Gothenburg, Sweden
| | - Romain Bachelard
- Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
- Université Côte d'Azur, CNRS, Institut de Physique de Nice, 06560 Valbonne, France
| | - Celso Jorge Villas-Boas
- Departamento de Física, Universidade Federal de São Carlos, 13565-905 São Carlos, SP, Brazil
| | - Markus Hennrich
- Department of Physics, Stockholm University, SE-106 91 Stockholm, Sweden
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3
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Leong WS, Xin M, Chen Z, Wang Y, Lan SY. Creation of Two-Mode Squeezed States in Atomic Mechanical Oscillators. PHYSICAL REVIEW LETTERS 2023; 131:193601. [PMID: 38000417 DOI: 10.1103/physrevlett.131.193601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 09/19/2023] [Indexed: 11/26/2023]
Abstract
Two-mode squeezed states, which are entangled states with bipartite quantum correlations in continuous-variable systems, are crucial in quantum information processing and metrology. Recently, continuous-variable quantum computing with the vibrational modes of trapped atoms has emerged with significant progress, featuring a high degree of control in hybridizing with spin qubits. Creating two-mode squeezed states in such a platform could enable applications that are only viable with photons. Here, we experimentally demonstrate two-mode squeezed states by employing atoms in a two-dimensional optical lattice as quantum registers. The states are generated by a controlled projection conditioned on the relative phase of two independent squeezed states. The individual squeezing is created by sudden jumps of the oscillators' frequencies, allowing generating of the two-mode squeezed states at a rate within a fraction of the oscillation frequency. We validate the states by entanglement steering criteria and Fock state analysis. Our results can be applied in other mechanical oscillators for quantum sensing and continuous-variable quantum information.
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Affiliation(s)
- Wui Seng Leong
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Mingjie Xin
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Zilong Chen
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Yu Wang
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
| | - Shau-Yu Lan
- Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
- Department of Physics, National Taiwan University, Taipei 10617, Taiwan
- Center for Quantum Science and Engineering, National Taiwan University, Taipei 10617, Taiwan
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4
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Katz O, Monroe C. Programmable Quantum Simulations of Bosonic Systems with Trapped Ions. PHYSICAL REVIEW LETTERS 2023; 131:033604. [PMID: 37540877 DOI: 10.1103/physrevlett.131.033604] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 05/14/2023] [Accepted: 06/23/2023] [Indexed: 08/06/2023]
Abstract
Trapped atomic ion crystals are a leading platform for quantum simulations of spin systems, with programmable and long-range spin-spin interactions mediated by excitations of phonons in the crystal. We describe a complementary approach for quantum simulations of bosonic systems using phonons in trapped-ion crystals, here mediated by excitations of the trapped-ion spins. The scheme enables a high degree of programability across a dense graph of bosonic couplings, utilizing long-lived collective phonon modes in a trapped-ion chain. As such, it is well suited for tackling hard problems such as boson sampling and simulations of long-range bosonic and spin-boson Hamiltonians.
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Affiliation(s)
- Or Katz
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Christopher Monroe
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
- IonQ, Inc., College Park, Maryland 20740, USA
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5
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Li BW, Mei QX, Wu YK, Cai ML, Wang Y, Yao L, Zhou ZC, Duan LM. Observation of Non-Markovian Spin Dynamics in a Jaynes-Cummings-Hubbard Model Using a Trapped-Ion Quantum Simulator. PHYSICAL REVIEW LETTERS 2022; 129:140501. [PMID: 36240415 DOI: 10.1103/physrevlett.129.140501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 09/13/2022] [Indexed: 06/16/2023]
Abstract
The Jaynes-Cummings-Hubbard (JCH) model is a fundamental many-body model for light-matter interaction. As a leading platform for quantum simulation, the trapped ion system has realized the JCH model for two to three ions. Here, we report the quantum simulation of the JCH model using up to 32 ions. We verify the simulation results even for large ion numbers by engineering low excitations and thus low effective dimensions; then we extend to 32 excitations for an effective dimension of 2^{77}, which is difficult for classical computers. By regarding the phonon modes as baths, we explore Markovian or non-Markovian spin dynamics in different parameter regimes of the JCH model, similar to quantum emitters in a structured photonic environment. We further examine the dependence of the non-Markovian dynamics on the effective Hilbert space dimension. Our Letter demonstrates the trapped ion system as a powerful quantum simulator for many-body physics and open quantum systems.
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Affiliation(s)
- B-W Li
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Q-X Mei
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - Y-K Wu
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - M-L Cai
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
- HYQ Co., Ltd., Beijing, 100176, People's Republic of China
| | - Y Wang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - L Yao
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
- HYQ Co., Ltd., Beijing, 100176, People's Republic of China
| | - Z-C Zhou
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
| | - L-M Duan
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, People's Republic of China
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6
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Jia Z, Wang Y, Zhang B, Whitlow J, Fang C, Kim J, Brown KR. Determination of Multimode Motional Quantum States in a Trapped Ion System. PHYSICAL REVIEW LETTERS 2022; 129:103602. [PMID: 36112437 DOI: 10.1103/physrevlett.129.103602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Revised: 08/12/2022] [Accepted: 08/15/2022] [Indexed: 06/15/2023]
Abstract
Trapped atomic ions are a versatile platform for studying interactions between spins and bosons by coupling the internal states of the ions to their motion. Measurement of complex motional states with multiple modes is challenging, because all motional state populations can only be measured indirectly through the spin state of ions. Here we present a general method to determine the Fock state distributions and to reconstruct the density matrix of an arbitrary multimode motional state. We experimentally verify the method using different entangled states of multiple radial modes in a five-ion chain. This method can be extended to any system with Jaynes-Cummings-type interactions.
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Affiliation(s)
- Zhubing Jia
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
| | - Ye Wang
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Bichen Zhang
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Jacob Whitlow
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Chao Fang
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
| | - Jungsang Kim
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
- IonQ, Inc., College Park, Maryland 20740, USA
| | - Kenneth R Brown
- Duke Quantum Center, Duke University, Durham, North Carolina 27701, USA
- Department of Physics, Duke University, Durham, North Carolina 27708, USA
- Department of Electrical and Computer Engineering, Duke University, Durham, North Carolina 27708, USA
- Department of Chemistry, Duke University, Durham, North Carolina 27708, USA
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7
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Podhora L, Lachman L, Pham T, Lešundák A, Číp O, Slodička L, Filip R. Quantum Non-Gaussianity of Multiphonon States of a Single Atom. PHYSICAL REVIEW LETTERS 2022; 129:013602. [PMID: 35841581 DOI: 10.1103/physrevlett.129.013602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 03/22/2022] [Accepted: 05/25/2022] [Indexed: 06/15/2023]
Abstract
Quantum non-Gaussian mechanical states are already required in a range of applications. The discrete building blocks of such states are the energy eigenstates-Fock states. Despite progress in their preparation, the remaining imperfections can still invisibly cause loss of the aspects critical for their applications. We derive and apply the most challenging hierarchy of quantum non-Gaussian criteria on the characterization of single trapped-ion oscillator mechanical Fock states with up to 10 phonons. We analyze the depth of these quantum non-Gaussian features under intrinsic mechanical heating and predict their requirement for reaching quantum advantage in the sensing of a mechanical force.
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Affiliation(s)
- L Podhora
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - L Lachman
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - T Pham
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 612 64 Brno, Czech Republic
| | - A Lešundák
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 612 64 Brno, Czech Republic
| | - O Číp
- Institute of Scientific Instruments of the Czech Academy of Sciences, Královopolská 147, 612 64 Brno, Czech Republic
| | - L Slodička
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
| | - R Filip
- Department of Optics, Palacký University, 17. listopadu 12, 77146 Olomouc, Czech Republic
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8
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Liu C, Mucci M, Cao X, Dutt MVG, Hatridge M, Pekker D. Proposal for a continuous wave laser with linewidth well below the standard quantum limit. Nat Commun 2021; 12:5620. [PMID: 34556650 PMCID: PMC8460663 DOI: 10.1038/s41467-021-25879-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 08/27/2021] [Indexed: 11/24/2022] Open
Abstract
Due to their high coherence, lasers are ubiquitous tools in science. We show that by engineering the coupling between the gain medium and the laser cavity as well as the laser cavity and the output port, it is possible to eliminate most of the noise due to photons entering as well as leaving the laser cavity. Hence, it is possible to reduce the laser linewidth by a factor equal to the number of photons in the laser cavity below the standard quantum limit. We design and theoretically analyze a superconducting circuit that uses Josephson junctions, capacitors and inductors to implement a microwave laser, including the low-noise couplers that allow the design to surpass the standard quantum limit. Our proposal relies on the elements of superconducting quantum information, and thus is an example of how quantum engineering techniques can inspire us to re-imagine the limits of conventional quantum systems.
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Affiliation(s)
- Chenxu Liu
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
- Department of Physics, Virginia Tech, Blacksburg, VA, 24061, USA.
| | - Maria Mucci
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Xi Cao
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - M V Gurudev Dutt
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Michael Hatridge
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - David Pekker
- Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
- Pittsburgh Quantum Institute, University of Pittsburgh, Pittsburgh, PA, 15260, USA.
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9
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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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10
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Abah O, Puebla R, Paternostro M. Quantum State Engineering by Shortcuts to Adiabaticity in Interacting Spin-Boson Systems. PHYSICAL REVIEW LETTERS 2020; 124:180401. [PMID: 32441978 DOI: 10.1103/physrevlett.124.180401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 04/20/2020] [Indexed: 06/11/2023]
Abstract
We present a fast and robust framework to prepare nonclassical states of a bosonic mode exploiting a coherent exchange of excitations with a two-level system ruled by a Jaynes-Cummings interaction mechanism. Our protocol, which is built on shortcuts to adiabaticity, allows for the generation of arbitrary Fock states of the bosonic mode, as well as coherent quantum superpositions of a Schrödinger cat-like form. In addition, we show how to obtain a class of photon-shifted states where the vacuum population is removed, a result akin to photon addition, but displaying more nonclassicality than standard photon-added states. Owing to the ubiquity of the spin-boson interaction that we consider, our proposal is amenable for implementations in state-of-the-art experiments.
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Affiliation(s)
- Obinna Abah
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Ricardo Puebla
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
| | - Mauro Paternostro
- Centre for Theoretical Atomic, Molecular and Optical Physics, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, United Kingdom
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11
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Entropy Exchange and Thermodynamic Properties of the Single Ion Cooling Process. ENTROPY 2019; 21:e21070650. [PMID: 33267364 PMCID: PMC7515143 DOI: 10.3390/e21070650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Revised: 06/27/2019] [Accepted: 06/28/2019] [Indexed: 12/02/2022]
Abstract
A complete quantum cooling cycle may be a useful platform for studying quantum thermodynamics just as the quantum heat engine does. Entropy change is an important feature which can help us to investigate the thermodynamic properties of the single ion cooling process. Here, we analyze the entropy change of the ion and laser field in the single ion cooling cycle by generalizing the idea in Reference (Phys. Rev. Lett.2015, 114, 043002) to a single ion system. Thermodynamic properties of the single ion cooling process are discussed and it is shown that the Second and Third Laws of Thermodynamics are still strictly held in the quantum cooling process. Our results suggest that quantum cooling cycles are also candidates for the investigation on quantum thermodynamics besides quantum heat engines.
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12
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Yung MH, Gao X, Huh J. Universal bound on sampling bosons in linear optics and its computational implications. Natl Sci Rev 2019; 6:719-729. [PMID: 34691927 PMCID: PMC8291458 DOI: 10.1093/nsr/nwz048] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2018] [Revised: 03/24/2019] [Accepted: 04/06/2019] [Indexed: 12/12/2022] Open
Abstract
In linear optics, photons are scattered in a network through passive optical elements including beam splitters and phase shifters, leading to many intriguing applications in physics, such as Mach-Zehnder interferometry, the Hong-Ou-Mandel effect, and tests of fundamental quantum mechanics. Here we present the fundamental limit in the transition amplitudes of bosons, applicable to all physical linear optical networks. Apart from boson sampling, this transition bound results in many other interesting applications, including behaviors of Bose-Einstein condensates (BEC) in optical networks, counterparts of Hong-Ou-Mandel effects for multiple photons, and approximating permanents of matrices. In addition, this general bound implies the existence of a polynomial-time randomized algorithm for estimating the transition amplitudes of bosons, which represents a solution to an open problem raised by Aaronson and Hance (Quantum Inf Comput 2012; 14: 541-59). Consequently, this bound implies that computational decision problems encoded in linear optics, prepared and detected in the Fock basis, can be solved efficiently by classical computers within additive errors. Furthermore, our result also leads to a classical sampling algorithm that can be applied to calculate the many-body wave functions and the S-matrix of bosonic particles.
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Affiliation(s)
- Man-Hong Yung
- Shenzhen Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Key Laboratory of Quantum Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China
- Central Research Institute, Huawei Technologies, Shenzhen 518129, China
| | - Xun Gao
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
| | - Joonsuk Huh
- Department of Chemistry, Sungkyunkwan University, Suwon 440-746, Korea
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13
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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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14
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Zhang X, Zhang K, Shen Y, Zhang S, Zhang JN, Yung MH, Casanova J, Pedernales JS, Lamata L, Solano E, Kim K. Experimental quantum simulation of fermion-antifermion scattering via boson exchange in a trapped ion. Nat Commun 2018; 9:195. [PMID: 29335446 PMCID: PMC5768889 DOI: 10.1038/s41467-017-02507-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 12/06/2017] [Indexed: 11/09/2022] Open
Abstract
Quantum field theories describe a variety of fundamental phenomena in physics. However, their study often involves cumbersome numerical simulations. Quantum simulators, on the other hand, may outperform classical computational capacities due to their potential scalability. Here we report an experimental realization of a quantum simulation of fermion-antifermion scattering mediated by bosonic modes, using a multilevel trapped ion, which is a simplified model of fermion scattering in both perturbative and non-perturbative quantum electrodynamics. The simulated model exhibits prototypical features in quantum field theory including particle pair creation and annihilation, as well as self-energy interactions. These are experimentally observed by manipulating four internal levels of a 171Yb+ trapped ion, where we encode the fermionic modes, and two motional degrees of freedom that simulate the bosonic modes. Our experiment establishes an avenue towards the efficient implementation of field modes, which may prove useful in studies of quantum field theories including non-perturbative regimes.
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Affiliation(s)
- Xiang Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, China.,Department of Physics, Renmin University of China, Beijing, 100872, China
| | - Kuan Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, China
| | - Yangchao Shen
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, China
| | - Shuaining Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, China
| | - Jing-Ning Zhang
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, China.
| | - Man-Hong Yung
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, China.,Institute for Quantum Science and Engineering and Department of Physics, Southern University of Science and Technology of China, Shenzhen, 518055, China.,Shenzhen Key Laboratory of Quantum Science and Engineering, Shenzhen, 518055, China
| | - Jorge Casanova
- Institut für Theoretische Physik and IQST, Universität Ulm, Albert-Einstein-Allee 11, D-89069, Ulm, Germany
| | - Julen S Pedernales
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080, Bilbao, Spain
| | - Lucas Lamata
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080, Bilbao, Spain
| | - Enrique Solano
- Department of Physical Chemistry, University of the Basque Country UPV/EHU, Apartado 644, 48080, Bilbao, Spain.,IKERBASQUE, Basque Foundation for Science, Maria Diaz de Haro 3, 48013, Bilbao, Spain.,Department of Physics, Shanghai University, 200444, Shanghai, China
| | - Kihwan Kim
- Center for Quantum Information, Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing, 100084, China.
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15
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Shen Y, Lu Y, Zhang K, Zhang J, Zhang S, Huh J, Kim K. Quantum optical emulation of molecular vibronic spectroscopy using a trapped-ion device. Chem Sci 2017; 9:836-840. [PMID: 29629150 PMCID: PMC5873044 DOI: 10.1039/c7sc04602b] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 11/19/2017] [Indexed: 12/23/2022] Open
Abstract
Here, we present the first quantum device that generates a molecular spectroscopic signal with the phonons in a trapped ion system, using SO2 as an example.
Molecules are one of the most demanding quantum systems to be simulated by quantum computers due to their complexity and the emergent role of quantum nature. The recent theoretical proposal of Huh et al. (Nature Photon., 9, 615 (2015)) showed that a multi-photon network with a Gaussian input state can simulate a molecular spectroscopic process. Here, we present the first quantum device that generates a molecular spectroscopic signal with the phonons in a trapped ion system, using SO2 as an example. In order to perform reliable Gaussian sampling, we develop the essential experimental technology with phonons, which includes the phase-coherent manipulation of displacement, squeezing, and rotation operations with multiple modes in a single realization. The required quantum optical operations are implemented through Raman laser beams. The molecular spectroscopic signal is reconstructed from the collective projection measurements for the two-phonon-mode. Our experimental demonstration will pave the way to large-scale molecular quantum simulations, which are classically intractable, but would be easily verifiable by real molecular spectroscopy.
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Affiliation(s)
- Yangchao Shen
- Center for Quantum Information , Institute for Interdisciplinary Information Sciences , Tsinghua University , Beijing 100084 , P. R. China .
| | - Yao Lu
- Center for Quantum Information , Institute for Interdisciplinary Information Sciences , Tsinghua University , Beijing 100084 , P. R. China .
| | - Kuan Zhang
- Center for Quantum Information , Institute for Interdisciplinary Information Sciences , Tsinghua University , Beijing 100084 , P. R. China .
| | - Junhua Zhang
- Center for Quantum Information , Institute for Interdisciplinary Information Sciences , Tsinghua University , Beijing 100084 , P. R. China .
| | - Shuaining Zhang
- Center for Quantum Information , Institute for Interdisciplinary Information Sciences , Tsinghua University , Beijing 100084 , P. R. China .
| | - Joonsuk Huh
- Department of Chemistry , Sungkyunkwan University , Suwon 16419 , Korea .
| | - Kihwan Kim
- Center for Quantum Information , Institute for Interdisciplinary Information Sciences , Tsinghua University , Beijing 100084 , P. R. China .
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16
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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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