A5048345090- Quantum Information and Cryptography
- Quantum Computing Algorithms and Architecture
- Quantum Mechanics and Applications
- Quantum optics and atomic interactions
- Mechanical and Optical Resonators
- Quantum and electron transport phenomena
- Atomic and Subatomic Physics Research
- Advanced NMR Techniques and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Spectroscopy and Quantum Chemical Studies
- Molecular spectroscopy and chirality
- Quantum chaos and dynamical systems
- Advanced Thermodynamics and Statistical Mechanics
- Acoustic Wave Phenomena Research
- Neural Networks and Reservoir Computing
- Quantum many-body systems
- Quantum Mechanics and Non-Hermitian Physics
- Scientific Measurement and Uncertainty Evaluation
- Laser-Matter Interactions and Applications
- NMR spectroscopy and applications
- Electron Spin Resonance Studies
- Photonic and Optical Devices
- Force Microscopy Techniques and Applications
- Dielectric materials and actuators
- Advanced Sensor and Energy Harvesting Materials
Chinese University of Hong Kong
2016-2025
Changchun University of Science and Technology
2022-2024
Universiti Malaysia Sarawak
2022-2023
Nagoya University
2022
Perimeter Institute
2022
Southern University of Science and Technology
2022
Weifang University of Science and Technology
2022
University of Science and Technology of China
2020
Hong Kong Polytechnic University
2012-2014
Massachusetts Institute of Technology
2007-2012
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...
A pivotal task in quantum metrology, and parameter estimation general, is to de- sign schemes that achieve the highest precision with given resources. Standard models of metrology usually assume dynamics fixed, achieved by preparing optimal probe states performing measurements. However, many practical experimental settings, additional controls are available alter dynamics. Here we propose use control methods for further improvement on limit estimation. We show exploring degree freedom...
Time is a valuable resource and it seems intuitive that longer time should lead to better precision in Hamiltonian parameter estimation. However recent studies have put this intuition into question, showing may even worse estimation certain cases. Here we show the can be restored if coherent feedback controls are included. By deriving asymptotically optimal present quantification of maximal improvement provide universal scaling for limit under scheme.
Measurement and estimation of parameters are essential for science engineering, where the main quest is to find highest achievable precision with given resources design schemes attain it. Two schemes, sequential feedback scheme parallel scheme, usually studied in quantum parameter estimation. While represents most general it remains unknown whether can outperform any tasks. In this Letter, we show that has a threefold improvement over Hamiltonian estimations on two-dimensional systems, an...
Most studies in multiparameter estimation assume the dynamics is fixed and focus on identifying optimal probe state measurements. In practice, however, controls are usually available to alter dynamics, which provides another degree of freedom. this paper we employ control methods, particularly gradient ascent pulse engineering (GRAPE), design for improvement precision limit estimation. We show that controlled schemes not only capable provide a higher limit, but also have stability inaccuracy...
The photonic router is a key device in optical quantum networks. Conventional routers, however, can only transfer photon from the input port to desired probabilistically. Here, we propose use chiral photon-atom interactions for targeted routing that single an arbitrarily selected output deterministically, i.e., with $100%$ probability. configuration of proposed consists driven three-level atom which chirally coupled two waveguides simultaneously. It shown that, by properly adjusting driving...
Quantum metrology can achieve far better precision than classical metrology, and is one of the most important applications quantum technologies in real world. To attain highest promised by all steps schemes need to be optimized, which include state preparation, parametrization, measurement. Here recent progresses on optimization these steps, are essential for identification achievement ultimate limit reviewed. It hoped this provides a useful reference researchers related fields.
One of the main quests in quantum metrology is to attain ultimate precision limit with given resources, where resources are not only number queries, but more importantly allowed strategies. With same restrictions on strategies constrain achievable precision. In this Letter, we establish a systematic framework identify different families strategies, including parallel, sequential, and indefinite-causal-order provide an efficient algorithm that determines optimal strategy within family under...
Abstract Two-mode interferometers lay the foundations for quantum metrology. Instead of exploring entanglement in two-mode interferometers, a single bosonic mode also promises measurement precision beyond shot-noise limit (SNL) by taking advantage infinite-dimensional Hilbert space Fock states. Here, we demonstrate single-mode phase estimation that approaches Heisenberg (HL) unconditionally. Due to strong dispersive nonlinearity and long coherence time microwave cavity, states form $$\left(...
The advantage of quantum metrology has been experimentally demonstrated for phase estimations where the dynamics are commuting. General noncommuting dynamics, however, can have distinct features. For example, direct sequential scheme, which achieve Heisenberg scaling estimation under commuting even worse performances than classical scheme when noncommuting. Here we realize a scalable optimally controlled precision general dynamics. We also present an intuitive geometrical framework and...
The precise measurement of a magnetic field is one the most fundamental and important tasks in quantum metrology. Although extensive studies on magnetometry have been carried out over past decades, ultimate precision that can be achieved for estimation all three components under parallel scheme remains unknown. This largely due to lack understandings incompatibility optimal probe states components. Here we provide an approach characterize minimal tradeoff among precisions multiple parameters...
The Heisenberg scaling, which scales as ${N}^{\ensuremath{-}1}$ in terms of the number particles or ${T}^{\ensuremath{-}1}$ evolution time, serves a fundamental limit quantum metrology. Better scalings, dubbed ``super-Heisenberg scaling,'' however, can also arise when generator parameter involves many-body interactions it is time dependent. All these different scalings actually be seen manifestations uncertainty relations. While there only one best scaling single-parameter metrology, coexist...
Quantum parameter estimation promises a high-precision measurement in theory, however, how to design the optimal scheme specific scenario, especially under practical condition, is still serious problem that needs be solved case by due existence of multiple mathematical bounds and optimization methods. Depending on scenario considered, different may more or less suitable, both terms computational complexity tightness bound itself. At same time, metrological schemes provided methods need...
Optimal control theory is a versatile tool that presents route to significantly improving figures of merit for quantum information tasks. We combine it here with the geometric local equivalence classes two-qubit operations derive an optimization algorithm determines best entangling gate given physical setting. demonstrate power this approach trapped polar molecules and neutral atoms.
Abstract One of the main quests in quantum metrology, and parameter estimation general, is to find out highest achievable precision with given resources design schemes attain it. In this article we present a general framework for provide systematic methods computing ultimate limit, which more efficient than conventional methods.
This work provides an operational definition of the quantum speed limit. The authors show that true limit should be independent time for non-controlled Hamiltonians and uncover a lousy purity can benefit reduction
Abstract Critical quantum metrology, which exploits critical systems as probes to estimate a physical parameter, has gained increasing attention recently. However, the metrology with continuous phase transition (QPT) is experimentally challenging since QPT only occurs at thermodynamic limit. Here, we propose an adiabatic scheme on perturbed Ising spin model first-order QPT. By introducing small transverse magnetic field, can not encode unknown parameter in ground state but also tune energy...
Experiments demonstrate very high precisions achieved simultaneously for multiple parameters with noncommuting generators.
Non-Hermitian quantum metrology, an emerging field at the intersection of estimation and non-Hermitian physics, holds promise for revolutionizing precision measurement. Here, we present a comprehensive investigation parameter in regime, with special focus on achieving Heisenberg scaling. We introduce concise expression Fisher information (QFI) that applies to general Hamiltonians, enabling analysis these systems. Our findings unveil remarkable potential systems attain scaling 1/ t , where...
<title>Abstract</title> Quantum metrology has emerged as a powerful tool for timekeeping, field sensing, and precision measurements within fundamental physics. With the advent of distributed quantum metrology, its capabilities have been extended to probing spatially parameters across networked systems. However, generating necessary non-local entanglement remains significant challenge, inherent incompatibility in multi-parameter estimation affects ultimate performance. Here we use...
Abstract By leveraging quantum effects, such as superposition and entanglement, metrology promises higher precision than the classical strategies. It is, however, a challenging task to achieve on practical systems. This is mainly due difficulties in engineering non-classical states performing nontrivial measurements system, especially when number of particles large. Here we propose variational scheme with Loschmidt echo for metrology. utilizing hardware-efficient Ansätze design circuits,...