A5100379575- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Quantum Mechanics and Applications
- Quantum many-body systems
- Quantum optics and atomic interactions
- Quantum and electron transport phenomena
- Cold Atom Physics and Bose-Einstein Condensates
- Robotic Mechanisms and Dynamics
- Spectroscopy and Quantum Chemical Studies
- Neural Networks and Reservoir Computing
- Mechanical and Optical Resonators
- Dynamics and Control of Mechanical Systems
- Topic Modeling
- Iterative Learning Control Systems
- Quantum chaos and dynamical systems
- Advanced Computational Techniques and Applications
- Distributed Control Multi-Agent Systems
- Semantic Web and Ontologies
- Quantum Chromodynamics and Particle Interactions
- Advanced Graph Neural Networks
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Advanced Fiber Laser Technologies
- Orbital Angular Momentum in Optics
Xiamen University
2016-2024
Chinese Academy of Sciences
1998-2024
Computer Network Information Center
2018-2024
Zhejiang University
2013-2023
Institute of Modern Physics
2013-2023
China North Industries Group Corporation (China)
2021-2023
Jiangxi University of Traditional Chinese Medicine
2023
Xinjiang Production and Construction Corps
2023
Zhejiang Sci-Tech University
2022
Shanghai Lixin University of Accounting and Finance
2020
Quantum Fisher information matrix (QFIM) is a core concept in theoretical quantum metrology due to the significant importance of Cramér-Rao bound parameter estimation. However, studies recent years have revealed wide connections between QFIM and other aspects mechanics, including thermodynamics, phase transition, entanglement witness, speed limit non-Markovianity. These indicate that more than metrology, but rather fundamental quantity mechanics. In this paper, we summarize properties...
We study the entanglement in quantum Heisenberg $\mathrm{XY}$ model which so-called W entangled states can be generated for 3 or 4 qubits. By concept of concurrence, we time evolution model. investigate thermal two-qubit isotropic with a magnetic field and anisotropic model, find that exists both ferromagnetic antiferromagnetic cases. Some evidences phase transition also appear these simple models.
We propose a simple scheme for the quantum teleportation of both bipartite and multipartite entangled coherent states with success probability 1/2. The is based only on linear optical devices such as beam splitters phase shifters, two-mode photon number measurements. channels described by maximally states, are readily made shifters.
We show that spin squeezing implies pairwise entanglement for arbitrary symmetric multiqubit states. If the parameter is less than or equal to 1, we demonstrate a quantitative relation between and concurrence even odd prove states generated from initial state with all qubits being down, via one-axis twisting Hamiltonian, are squeezed if only they entangled. For Hamiltonian an external transverse field any number of greater 1 two-axis countertwisting qubits, numerical results suggest such
Quantum Fisher information of a parameter characterizes the sensitivity state with respect to changes parameter. In this article, we study quantum $\mathrm{SU}(2)$ rotations under three decoherence channels: amplitude-damping, phase-damping, and depolarizing channels. The initial is chosen be Greenberger-Horne-Zeilinger which phase can achieve Heisenberg limit. By using Kraus operator representation, obtained analytically. We observe decay sudden change in all
We find a phase-matching condition for enhancement of sensitivity in Mach-Zehnder interferometer illuminated by an arbitrary state one input port and odd (even) the other port. Under this condition, Fisher information becomes maximal with respect to relative phase two modes, is enhanced. For case photon losses, we further that remains unchanged coherent superposition as states.
We study the entanglement of thermal and ground states in Heisernberg $XX$ qubit rings with a magnetic field. A general result is found that for even-number pairwise between nearest-neighbor qubits independent on both sign exchange interaction constants fields. As an example we four-qubit model find state this without fields shown to be four-body maximally entangled measured by $N$-tangle.
We study the threshold temperature for pairwise thermal entanglement in spin-1/2 isotropic Heisenberg model up to 11 spins and find that odd even number of qubits approaches dynamical limit from below above, respectively. The thermodynamical is estimated. investigate many-particle both ground states system, state four-qubit four-particle entangled before a temperature.
We study the dynamical process of disentanglement two qubits and qutrits coupled to an Ising spin chain in a transverse field, which exhibits quantum phase transition. use concurrence negativity quantify entanglement qutrits, respectively. Explicit connections between (negativity) decoherence factors are given for initial states, pure maximally entangled state mixed Werner state. find that decay exponentially with fourth power time vicinity critical point environmental system.
In order to witness multipartite correlations beyond pairwise entanglement, spin-squeezing parameters are analytically calculated for a spin ensemble in collective initial state under three different decoherence channels. It is shown that, analogy the squeezing described by can suddenly become zero at vanishing times. This finding shows general occurrence of sudden phenomena quantum many-body systems, which here referred as death (SSSD). that SSSD usually occurs due and never some states...
We give conditions under which general bipartite entangled non-orthogonal states become maximally states. Using these we construct a large class of with exactly one ebit entanglement in both and multipartite systems. One remarkable property is that the amount this independent on parameters involved Finally discuss how to generate
We propose a scheme for generating multipartite entangled coherent states via entanglement swapping, with an example of physical realization in ion traps. Bipartite these is quantified by the concurrence. also compute certain systems. Finally we establish that results can be applied to more general nonorthogonal states.
We study pairwise thermal entanglement in three-qubit Heisenberg models and obtain analytic expressions for the concurrence. find that is absent from both antiferromagnetic XXZ model, ferromagnetic model with anisotropy parameter Δ⩾1. Conditions existence of are discussed detail, as role degeneracy effects magnetic fields on quantum phase transition. Specifically, we uniform field can induce XXX but cannot model.
We derive a general expression of the quantum Fisher information for Mach-Zehnder interferometer, with port inputs an \emph{arbitrary} pure state and squeezed thermal state. find that standard limit can be beaten, when even or odd states are applied to pure-state port. In particular, becomes state, all have same given photon numbers. For optimal needed approach Heisenberg limit. As examples, we consider several common states: Fock states, coherent vacuum single-photon-subtracted states. also...
Analyses of phenomena exhibiting finite-time decay quantum entanglement have recently attracted considerable attention. Such is often referred to as sudden vanishing (or death) entanglement, which can be followed by its reappearance rebirth). We analyze various decays (for dissipative systems) and analogous periodic vanishings unitary nonclassical correlations described violations classical inequalities the corresponding nonclassicality witnesses quantumness witnesses), are not necessarily...
We study spin squeezing under non-Markovian channels, and consider an ensemble of $N$ independent spin-1/2 particles with exchange symmetry. Each interacts its own bath, the baths are identical. For this kind open system, decoherence can be investigated from dynamics local expectations, multi-qubit reduced into two-qubit one. The is obtained by hierarchy equation method, which a exact without rotating-wave Born-Markov approximation. numerical results show that displays multiple sudden...
We give an analytical result for the quantum Fisher information of entangled coherent States in a lossy Mach-Zehnder Interferometer recently proposed by J. Joo et al. [Phys. Rev. Lett. 107, 083601(2011)]. For small loss photons, we find that state can surpass Heisenberg limit. Furthermore, The formalism developed here is applicable to study phase sensitivity multipartite states.
In this paper, we investigate the effect of different optical field initial states on performance Tavis-Cummings (T-C) quantum battery. solving dynamical evolution system, found a fast way to solve Bethe ansatz equation. We find that stored energy and average charging power T-C battery are closely related probability distribution state in number states. define quantity called number-state energy. With prescribed quantity, only need know obtain at any time. propose an equal expected value...
We study the entanglement of unitary operators on ${d}_{1}\ifmmode\times\else\texttimes\fi{}{d}_{2}$ quantum systems. This quantity is closely related to entangling power associated evolutions. The a class quantified by concept concurrence.
We propose a generalized form of entangled coherent states (ECS) and apply them in multi-arm optical interferometer to estimate multiple phase shifts.We obtain the quantum Cramér-Rao bounds for both linear nonlinear parameterization protocols.Through analysis, we find that, utilizing simultaneous estimation, this ECS gives better precision than NOON [Phys.Rev. Lett.111, 070403 (2013)].Moreover, comparing with independent protocols have same advantage relation number parameters.