Article
Optics
Xiao-Jun Liao, Yong-Qi Fu
Summary: This article treats the imaging process and its corresponding state estimation as parallel mode channels and two estimation subproblems, respectively. In the two subproblems, the displacement vector and covariance matrix of the object field are estimated independently using respective quantum mechanically defined cost functions. The results show that using only the displacement vector for estimation does not significantly enhance the resolution of the amplitude image, but the quantum Cramer-Rao bound of spatial resolution can be pushed down toward the uncertainty relation. Furthermore, high quantum fidelities verify the effectiveness and broad applicability of the estimation to arbitrary multimode Gaussian states.
Article
Optics
Christian Drago, Agata M. Branczyk
Summary: In this paper, a method for generating tunable squeezed vacuum states of light with multiple modes encoded in frequency bins is proposed. The method utilizes custom-engineered spontaneous parametric down-conversion driven by a pulse-shaped pump field to generate multimode squeezed states, which can be tuned in real time by adjusting the properties of the pump field. Exploring new quantum states of light encoded in new degrees of freedom can be a fruitful path towards discovering new quantum applications.
Article
Quantum Science & Technology
R. Muthuganesan, V. K. Chandrasekar
Summary: In this paper, the resource theory of asymmetry is established using quantum Fisher information, with the average Fisher information defined as a measure of asymmetry. The discrepancy of bipartite global and local asymmetries is shown to naturally induce nonclassical correlation between subsystems. This measure satisfies all the necessary axioms of a faithful measure of bipartite quantum correlation and has been studied for various types of quantum states.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Physics, Multidisciplinary
Sergii Strelchuk, Michal Studzinski
Summary: There are two types of port-based teleportation (PBT) protocols: deterministic and probabilistic. We introduce the minimal requirements for a feasible PBT protocol and construct a simple PBT protocol that teleports an unknown quantum state with certain success probability and fidelity using maximally entangled states. We also define efficient superdense coding protocols and rigorous methods for comparing and converting between different PBT protocols.
NEW JOURNAL OF PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
M. Hammani, A. Chouikh, T. Said, M. Bennai
Summary: We proposed a scheme to implement the CNOT gate using photonic qubits encoded on cavity modes and a four-level atom. The location of resonance was predicted using an effective three-level Hamiltonian. The interaction of multi-level atom with multi-mode fields in a cavity was theoretically studied and numerically calculated, along with analyzing the effects of decoherence using wave-function and density matrix approaches.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Chemistry, Physical
Roberto Marquardt
Summary: The concept of a thermal wave packet and the spatial probability distribution are explained using the example of freely moving particles. The localization of particles and the use of localized Gaussian wave packets to describe the thermal state of freely moving particles are critically assessed.
Article
Astronomy & Astrophysics
Akira Ono
Summary: A limitation of time-dependent mean-field approaches is the lack of quantum tunneling for collective motions. This article proposes a simplified one-dimensional model to describe the relative motion of colliding nuclei, and investigates the transmission of potential barriers by analyzing the time evolution of phase space distribution. It is found that the behavior of free propagation depends on the number of superposed wave packets.
Article
Astronomy & Astrophysics
Kazuki Ikeda
Summary: Quantum field theory can be used for communication through quantum energy teleportation. In our demonstration, we used the massive Thirring model, a relativistic fermionic field theory of self-coupled fermions, to teleport energy. Our results show a strong relationship between the teleported energy and the phase diagram of the theory, with energy peaking near phase transition points. These results, obtained through measuring local subsystems, reduce noise from quantum computation and enable efficient quantum simulations. Moreover, this entanglement-based method allows for the discovery of global structure through local measurements.
Article
Materials Science, Multidisciplinary
D. D. Solnyshkov, C. Leblanc, L. Bessonart, A. Nalitov, Jiahuan Ren, Qing Liao, Feng Li, G. Malpuech
Summary: In non-Hermitian systems, the quantum metric plays a crucial role near exceptional points, controlling wave-packet trajectories with constant acceleration and velocity.
Article
Optics
Ayan Patra, Rivu Gupta, Saptarshi Roy, Tamoghna Das, Aditi Sen(De)
Summary: This study introduces a framework of a multimode dense coding network for communication between multiple senders and a single receiver using continuous variable systems. The research shows that the dense coding capacity increases with the amount of energy transmitted from the senders to the receiver, demonstrating the quantum advantage of the protocol.
Article
Physics, Multidisciplinary
Necati celik, Nueket uenal
Summary: In quantum teleportation, the joint state of the sender and receiver qubits, rearranged in terms of the appropriate number of Bell-type states, plays a crucial role in the successful transmission of arbitrary n-qubit states. A method for efficiently producing Bell-type states for teleportation, particularly for three-qubit states, is proposed.
CHINESE JOURNAL OF PHYSICS
(2022)
Article
Chemistry, Physical
Laura Bancroft, Yunfan Qiu, Matthew D. Krzyaniak, Michael R. Wasielewski
Summary: The study demonstrated photodriven quantum teleportation of an electron spin state in a covalent donor-acceptor-radical system. Varying the time between spin state preparation and photoinitiated teleportation had effects on the results, with oscillatory behavior observed. Understanding experimental parameters is crucial for leveraging this phenomenon for quantum information applications.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Engineering, Electrical & Electronic
Yousef Mafi, Payman Kazemikhah, Armin Ahmadkhaniha, Hossein Aghababa, Mohammadreza Kolahdouz
Summary: This article presents a new bidirectional teleportation protocol using 2n entangled Bell-states as the quantum channel for transmitting an arbitrary number of qubits. The proposed protocol is more straightforward, uses minimal resources, and has been validated on the IBM Quantum experience platform.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Multidisciplinary Sciences
Jia-Qi Wang, Yuan-Hao Yang, Ming Li, Haiqi Zhou, Xin-Biao Xu, Ji-Zhe Zhang, Chun-Hua Dong, Guang-Can Guo, C-L Zou
Summary: Nonlinear optics processes play a critical role in photonics and quantum optics for their importance in light sources and information processing. In this study, the authors successfully synthesized a high-order nonlinear process (chi((4))) by combining low-order processes in a microcavity, overcoming the limitations of materials' small intrinsic high-order susceptibility. This approach opens up new possibilities for achieving high-order optical nonlinearities and exploring functional photonic devices.
NATURE COMMUNICATIONS
(2022)
Article
Quantum Science & Technology
Tomoki Yamagami, Etsuo Segawa, Norio Konno
Summary: The study extends the scheme of quantum teleportation by quantum walks and introduces the mathematical definition and necessary conditions for achieving quantum teleportation rigorously. The results classify the parameters necessary for the successful accomplishment of quantum teleportation.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Engineering, Electrical & Electronic
Naoto Takanashi, Takahiro Kashiwazaki, Takushi Kazama, Koji Enbutsu, Ryoichi Kasahara, Takeshi Umeki, Akira Furusawa
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2020)
Article
Physics, Multidisciplinary
Fumiya Okamoto, Mamoru Endo, Mikihisa Matsuyama, Yuya Ishizuka, Yang Liu, Rei Sakakibara, Yosuke Hashimoto, Jun-ichi Yoshikawa, Peter van Loock, Akira Furusawa
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Applied
Shunya Konno, Atsushi Sakaguchi, Warit Asavanant, Hisashi Ogawa, Masaya Kobayashi, Petr Marek, Radim Filip, Jun-ichi Yoshikawa, Akira Furusawa
Summary: In this paper, a superposition between a vacuum state and a single-photon state with maximized nonlinear squeezing is generated and observed in real-time quadrature measurements. This work presents an important step in extending continuous-variable quantum information processing from the Gaussian regime to the non-Gaussian regime.
PHYSICAL REVIEW APPLIED
(2021)
Correction
Engineering, Electrical & Electronic
Naoto Takanashi, Takahiro Kashiwazaki, Takushi Kazama, Koji Enbutsu, Ryoichi Kasahara, Takeshi Umeki, Akira Furusawa
IEEE JOURNAL OF QUANTUM ELECTRONICS
(2021)
Article
Physics, Applied
Takahiro Kashiwazaki, Taichi Yamashima, Naoto Takanashi, Asuka Inoue, Takeshi Umeki, Akira Furusawa
Summary: A low-loss quasi-single-mode periodically poled LiNbO3 (PPLN) waveguide was fabricated using mechanical polishing processes, which allowed for larger squeezing level. This waveguide was utilized to assemble a low-loss fiber-pigtailed OPA module, showing promising results for high-speed large-scale fault-tolerant quantum computing. The waveguide did not exhibit pump-induced optical loss even under high power pumping conditions.
APPLIED PHYSICS LETTERS
(2021)
Article
Physics, Multidisciplinary
Kosuke Fukui, Shuntaro Takeda, Mamoru Endo, Warit Asavanant, Jun-ichi Yoshikawa, Peter van Loock, Akira Furusawa
Summary: Non-Gaussian states are crucial for optical quantum technologies, and the optical quantum state synthesizer (OQSS) is a promising method for their preparation. However, the complexity of simulating state preparation on a classical computer poses a significant challenge. To overcome this, we propose a backcasting approach and show that the requirements for photon-number resolving detectors can be significantly reduced.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Applied
A. Inoue, T. Kashiwazaki, T. Yamashima, N. Takanashi, T. Kazama, K. Enbutsu, K. Watanabe, T. Umeki, M. Endo, A. Furusawa
Summary: In this work, a real-time amplitude measurement method for continuous-variable optical quantum information processing is developed using a modular optical parametric amplifier (OPA) and a broadband balanced photodiode. This method improves the clock frequency limitation of homodyne detectors and enables the realization of high clock frequency optical quantum computers and multi-core systems.
APPLIED PHYSICS LETTERS
(2023)
Article
Physics, Applied
Takahiro Kashiwazaki, Taichi Yamashima, Koji Enbutsu, Takushi Kazama, Asuka Inoue, Kosuke Fukui, Mamoru Endo, Takeshi Umeki, Akira Furusawa
Summary: We achieved continuous-wave 8.3 dB squeezed light generation using a terahertz-order-broadband waveguide optical parametric amplifier through improvements in the measurement setup. By reducing optical loss and minimizing phase-locking fluctuations, we were able to optimize the experimental parameters for squeezing levels. This highly squeezed light without loss-correction and circuit-noise correction holds promise for fault-tolerant ultra-fast optical quantum computers.
APPLIED PHYSICS LETTERS
(2023)
Article
Quantum Science & Technology
Kan Takase, Kosuke Fukui, Akito Kawasaki, Warit Asavanant, Mamoru Endo, Jun-ichi Yoshikawa, Peter van Loock, Akira Furusawa
Summary: This article proposes a synthesizer that encodes Gottesman-Kitaev-Preskill (GKP) qubits in propagating light by exploiting the nonlinearity of photon detectors. The synthesizer offers several advantages, including systematic and rigorous synthesis of arbitrary GKP qubits, minimal resource usage, high fidelity and success probability, and robustness against loss.
NPJ QUANTUM INFORMATION
(2023)
Article
Optics
Warit Asavanant, Kosuke Fukui, Atsushi Sakaguchi, Akira Furusawa
Summary: This paper presents an optical quantum computation platform that does not require optical switches. Instead, it is based on continuous-variable measurement-based quantum computation, where the quantum entanglement structure is modified to allow quantum teleportation to replace optical switching and rerouting. The architecture also includes additional modes that enable the teleportation of quantum states along the cluster state, a task typically requiring optical switches.
Article
Optics
Kosuke Fukui, Mamoru Endo, Warit Asavanant, Atsushi Sakaguchi, Jun-ichi Yoshikawa, Akira Furusawa
Summary: This article introduces a method to generate optical GKP qubits using cross-Kerr interaction and validates its feasibility through numerical calculations. The results show that the method is capable of generating GKP qubits with the required quality, achieving high fidelity and success probability.
Article
Optics
Fumiya Hanamura, Warit Asavanant, Kosuke Fukui, Shunya Konno, Akira Furusawa
Summary: This study focuses on the estimation and error correction of displacements in continuous-variable quantum information processing using non-Gaussian states. Analysis of complex GKP states and experimentally feasible single-photon states reveals the importance of non-Gaussianity for displacement estimation, demonstrating that non-Gaussian states can surpass the lower bound achieved with Gaussian operations.
Article
Physics, Multidisciplinary
Shunya Konno, Warit Asavanant, Kosuke Fukui, Atsushi Sakaguchi, Fumiya Hanamura, Petr Marek, Radim Filip, Jun-ichi Yoshikawa, Akira Furusawa
Summary: This paper explores the method of implementing non-Clifford operations on GKP qubits, achieving high-fidelity linear optical implementation by combining nonlinear feedforward and GKP-encoded ancillary states.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Optics
Warit Asavanant, Kan Takase, Kosuke Fukui, Mamoru Endo, Jun-ichi Yoshikawa, Akira Furusawa
Summary: The study introduces a new method to tailor the wave functions of quantum states using non-Gaussian entangled states, allowing for the generation of various classes of quantum states. The results highlight the importance of conditioning using homodyne measurements in complement to photon number detection for generating non-Gaussian states.
Article
Optics
Kan Takase, Jun-ichi Yoshikawa, Warit Asavanant, Mamoru Endo, Akira Furusawa
Summary: We propose a high-rate generation method of optical Schrodinger cat states by photon number measurement in one mode of two-mode Gaussian states, which relaxes constraints on experimental parameters and allows for a high generation rate. This method can potentially exceed conventional photon subtraction rates by about 103 to 106 times, making it important for quantum computing applications.
