Article
Optics
John Drew Wilson, Simon B. Jaeger, Jarrod T. Reilly, Athreya Shankar, Maria Luisa Chiofalo, Murray J. Holland
Summary: The creation and manipulation of quantum entanglement is crucial for improving precision measurements. This study introduces a method that goes beyond one-axis twisting to generate squeezing and entanglement across two distinct degrees of freedom. By using a nonlinear Hamiltonian to generate dynamics in SU(4), more rich context of quantum entanglement is achieved.
Article
Optics
Tuguldur Kh Begzjav, Girish S. Agarwal
Summary: This study investigates the squeezing of quantum systems with SU(3) symmetry using a one-axis twisting Hamiltonian, finding interesting connections between the squeezing of spin-1/2 and spin-1 systems. The squeezing parameters for spin-1 subalgebras are not only dependent on structure constants, but also on the anticommutation relations of the subalgebras. Results are reported for subalgebras with vanishing anticommutators and nematic squeezing, while known results are recovered in other cases.
Article
Physics, Applied
Sebastian C. Carrasco, Michael H. Goerz, Zeyang Li, Simone Colombo, Vladan Vuletic, Vladimir S. Malinovsky
Summary: We propose a scheme for generating optimal squeezed states for Ramsey interferometry, which consists of alternating one-axis twisting pulses and rotations. The resulting states show a metrological gain proportional to the Heisenberg limit, even when constraints on pulse amplitude and realistic losses are taken into account.
PHYSICAL REVIEW APPLIED
(2022)
Article
Optics
Abeer Alhashash, Nour Zidan, Nasser Metwally
Summary: The study examined the possibility of estimating parameters and describing the optimal states induced from the one-axis twisting model on the thermal state. The quantum Fisher information matrix was used as an estimator for multiple parameters, showing that concurrent estimation reduces parameter variance and improves precision. Additionally, saturation was observed at higher temperatures, despite increasing minimum variations in reaction force.
Article
Physics, Multidisciplinary
Marcin Plodzien, Maciej Lewenstein, Emilia Witkowska, Jan Chwedenczuk
Summary: We demonstrate that one-axis twisting (OAT) is a powerful source of many-body Bell correlations for creating nonclassical states of bosonic qubits. We develop an analytical and universal treatment that allows us to identify the critical time for the emergence of Bell correlations and predict their depth at subsequent times. Our findings are illustrated using a highly nontrivial example of OAT dynamics generated with the Bose-Hubbard model.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Youcef Baamara, Alice Sinatra, Manuel Gessner
Summary: This paper develops strategies for achieving optimal quantum enhancements using non-Gaussian states in interferometric precision measurements. The authors show that measurement-after-interaction techniques are effective in measuring nonlinear spin observables, and they determine analytically the quantum enhancement of non-Gaussian over-squeezed states considering the presence of decoherence processes.
COMPTES RENDUS PHYSIQUE
(2022)
Article
Materials Science, Multidisciplinary
Stefano Scopa, Pasquale Calabrese, Lorenzo Piroli
Summary: This study revisits early suggestions to observe spin-charge separation in cold-atom settings by studying the evolution of one-dimensional repulsive Fermi gases in a harmonic potential. The results show that at low temperature and zero magnetic field, spin and charge dynamically decouple with quantitatively small quantum corrections. At finite temperature, the effects of spin-charge separation still persist, and the specific temperature at which the two distinguishable excitations melt is explicitly characterized through numerical simulations of the GHD equations.
Article
Physics, Multidisciplinary
Liang Hu, Xiangming Hu, Junyu Chen, Jun Xu, Deyi Kong
Summary: We propose a spin two-axis-twisting mechanism using coherent population trapping (CPT) based atom-photon interactions. CPT occurs when the ground states are resonantly coupled to a common excited state, resulting in atoms trapped in the dark state. Close to CPT, the atoms behave as two dark-state based spins and interact with the common cavity vacuum fields. The previously non-existent interaction between them is responsible for the twisting of the ground state spin. The compatibility of twisting spin squeezing with resonant atom-light interaction makes this scheme different from previous ones. The CPT resonant unit serves as a new ingredient for quantum networks.
NEW JOURNAL OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
T. Hernandez Yanes, M. Plodzien, M. Mackoit Sinkeviciene, G. Zlabys, G. Juzeliunas, E. Witkowska
Summary: This study demonstrates the activation of spin-squeezing protocols to generate correlated many-body quantum states in a system of ultracold atomic fermions using position-dependent laser coupling.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Tian-Wei Mao, Qi Liu, Xin-Wei Li, Jia-Hao Cao, Feng Chen, Wen-Xin Xu, Meng Khoon Tey, Yi-Xiao Huang, Li You
Summary: A record enhancement in nonlinear interferometry has been achieved by using spin-nematic squeezed states of atomic Bose-Einstein condensates, which can have potential applications in atomic magnetometers, atomic clocks, and fundamental tests of Lorentz symmetry violations.
Article
Optics
Tommaso Comparin, Fabio Mezzacapo, Tommaso Roscilde
Summary: Research has shown that a large class of S = 1/2 spin Hamiltonians with axial symmetry can generate robust squeezing dynamics, which is related to the unique structure of low-lying Hamiltonian eigenstates called Anderson's tower of states. These states are connected to spontaneous symmetry breaking in quantum systems and can be closely related to the eigenstates of a planar rotor for models with high connectivity. This study reveals the squeezing power of various Hamiltonian dynamics implemented by different quantum simulation platforms.
Article
Optics
Long-Gang Huang, Xuanchen Zhang, Yanzhen Wang, Zhenxing Hua, Yuanjiang Tang, Yong-Chun Liu
Summary: Spin squeezing is crucial for quantum metrology and quantum information science, but its generation faces challenges due to the lack of squeezing interactions in existing physical systems. In this study, we propose a universal scheme to generate spin squeezing in coupled spin models with collective spin-spin interactions. We can transform the coupled spin interactions into squeezing interactions and achieve extreme squeezing with Heisenberg-limited measurement precision scaling as 1/N for N particles. Only constant and continuous driving fields are required, making it accessible for current realistic experiments. This work greatly expands the systems capable of generating Heisenberg-limited spin squeezing, with broad applications in quantum precision measurement.
Article
Materials Science, Multidisciplinary
Pontus Laurell, Gonzalo Alvarez, Elbio Dagotto
Summary: We calculate the dynamical spin structure factor of the generalized spin-1/2 compass spin chain using the density matrix renormalization group. The model, also known as the twisted Kitaev spin chain, was recently proposed to be relevant for the description of the spin chain compound CoNb2O6. It features bond-dependent interactions and interpolates between an Ising chain and a one-dimensional variant of Kitaev's honeycomb spin model. The structure factor, in turn, is found to interpolate from gapped and nondispersive in the Ising limit to gapless with nontrivial continua in the Kitaev limit. In particular, the component of the structure factor perpendicular to the Ising directions changes abruptly at the Kitaev point into a dispersionless continuum due to the emergence of an extensive ground-state degeneracy. We show this continuum is consistent with analytical Jordan-Wigner results. We also discuss implications for future inelastic scattering experiments and applications to materials, particularly CoNb2O6.
Article
Engineering, Mechanical
Qiucheng Yang, Chunmei Liu, Cheng Cheng, Jie Tao, Xueshan Bai, Ziqi Ma, Xunzhong Guo
Summary: This study proposes an analytical model of the bending die trajectory for one-time forming of square tube spiral components, and reveals the laws of stress, strain, wall thickness distribution, and cross section distortion of these components during the forming process.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2022)
Article
Multidisciplinary Sciences
Ruwan Senaratne, Danyel Cavazos-Cavazos, Sheng Wang, Feng He, Ya-Ting Chang, Aashish Kafle, Han Pu, Xi-Wen Guan, Randall G. Hulet
Summary: Confining ultracold atoms to periodic potentials is a powerful method for simulating complex many-body systems. In this study, we confined fermions to one dimension to realize the Tomonaga-Luttinger liquid model and observed a velocity shift of spin and charge excitations in opposite directions, indicating the existence of spin-charge separation.
Editorial Material
Multidisciplinary Sciences
Yong-Chun Liu, Kun Huang, Yun-Feng Xiao, Lan Yang, Cheng-Wei Qiu
NATIONAL SCIENCE REVIEW
(2021)
Article
Optics
Xinyao Huang, Cuicui Lu, Chao Liang, Honggeng Tao, Yong-Chun Liu
Summary: Nonreciprocity is important in optical information processing and topological photonics studies. Conventional methods for achieving nonreciprocity rely on magnetic fields, spatiotemporal modulation, or nonlinearity. However, this study introduces a new generic principle for generating nonreciprocity using energy loss, providing a potential avenue for designing nonreciprocal devices without strict requirements.
LIGHT-SCIENCE & APPLICATIONS
(2021)
Article
Crystallography
Qinghong Liao, Weida Bao, Xing Xiao, Wenjie Nie, Yongchun Liu
Summary: In this study, the optomechanically induced transparency phenomenon and fast and slow light effects of a four-mode optomechanical system with a Kerr medium were theoretically investigated. It was found that the stability of the system can be adjusted by changing the Kerr coefficient. The study showed potential applications in quantum optical devices and quantum information processing by controlling the fast and slow light effects in the system.
Article
Quantum Science & Technology
Qinghong Liao, Jing Wu, Weican Deng, Xing Xiao, Yongchun Liu
Summary: This study proposes a dynamic dissipative synchronous cooling method for simultaneous cooling of two mechanical resonators in the strong optomechanical coupling regime, achieving ground-state cooling for both resonators. The synchronized modulation of cavity dissipation accelerates the cooling process significantly, with analytical cooling limits deriving results consistent with numerical simulations. This scheme opens new prospects for research in multiple-mode ground-state cooling of mechanical resonators.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Quantum Science & Technology
Long-Gang Huang, Feng Chen, Xinwei Li, Yaohua Li, Rong Lu, Yong-Chun Liu
Summary: This study proposes a generic scheme to synthesize spin squeezing in non-squeezing systems by using periodical rotation pulses. The original non-squeezing interaction can be transformed into squeezing interaction with significantly enhanced interaction strength. The generated spin squeezing is capable of achieving the Heisenberg limit with measurement precision proportional to 1/N for N particles.
NPJ QUANTUM INFORMATION
(2021)
Article
Physics, Multidisciplinary
Yaohua Li, Chao Liang, Chenyang Wang, Cuicui Lu, Yong-Chun Liu
Summary: The study reveals the gain-loss-induced hybrid second-order skin-topological effect and the PT phase transition in skin-topological modes. The localized behavior of topological edge modes on a special type of corner, in contrast to the extended bulk modes, is found to be related to the interplay between gain, loss, and the chiral edge currents induced by nonlocal flux. The research establishes a relation between the skin-topological effect and the PT symmetries belonging to different edges.
PHYSICAL REVIEW LETTERS
(2022)
Article
Multidisciplinary Sciences
Cuicui Lu, Yi-Zhi Sun, Chenyang Wang, Hongyu Zhang, Wen Zhao, Xiaoyong Hu, Meng Xiao, Wei Ding, Yong-Chun Liu, C. T. Chan
Summary: The authors provide experimental observation of a topological rainbow in a silicon-based nanophotonic chip, presenting a robust platform for next-generation nanophotonic chips. The topological rainbow separates and traps different frequencies of topological photonic states into different positions, promising high-density integration on-chip.
NATURE COMMUNICATIONS
(2022)
Article
Optics
Qinghong Liao, Liangtao Zhou, Xiaoqian Wang, Yongchun Liu
Summary: A hybrid intracavity squeezing optomechanical cooling system is proposed to achieve ground state cooling of the mechanical resonator in the highly unresolved sideband regime. The system effectively suppresses quantum backaction heating through intracavity squeezing and enhances cooling by adjusting the tunnel coupling between cavities. It exhibits good performance in resisting environmental thermal noise and has better tolerance for the quality factor of the auxiliary cavity, providing possibilities for quantum manipulation of large mass and low frequency mechanical resonators.
Article
Physics, Multidisciplinary
Yuanjiang Tang, Chao Liang, Xin Wen, Weipeng Li, An-Ning Xu, Yong-Chun Liu
Summary: We propose a PT-symmetric feedback method to narrow the linewidths of resonance systems, achieving remarkable linewidth narrowing and enhancement of measurement sensitivity. By transforming a dissipative resonance system into a PT-symmetric system, using a quadrature measurement-feedback loop, the method only requires a single resonance mode, greatly extending its scope of applications. In a thermal ensemble of atoms, we demonstrate a 48-fold narrowing of the magnetic resonance linewidth and a 22-times improvement in measurement sensitivity in magnetometry, opening new avenues for studying nonHermitian physics and high-precision measurements in resonance systems with feedback.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Chao Liang, Yuanjiang Tang, An-Ning Xu, Yong-Chun Liu
Summary: In this study, we experimentally observe EPs and enhance magnetic field sensing in thermal atomic ensembles. We use the rich energy levels of atoms to construct effective decays and propose an optical polarization rotation measurement scheme for detecting resonance peak splitting, which has an advantage over conventional transmission measurement schemes. Additionally, our system allows flexible adjustment of the effective coupling strength and decay rates, enabling tunable EP positions and expanding the measurement range.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Long-Gang Huang, Xuanchen Zhang, Yanzhen Wang, Zhenxing Hua, Yuanjiang Tang, Yong-Chun Liu
Summary: Spin squeezing is crucial for quantum metrology and quantum information science, but its generation faces challenges due to the lack of squeezing interactions in existing physical systems. In this study, we propose a universal scheme to generate spin squeezing in coupled spin models with collective spin-spin interactions. We can transform the coupled spin interactions into squeezing interactions and achieve extreme squeezing with Heisenberg-limited measurement precision scaling as 1/N for N particles. Only constant and continuous driving fields are required, making it accessible for current realistic experiments. This work greatly expands the systems capable of generating Heisenberg-limited spin squeezing, with broad applications in quantum precision measurement.
Article
Optics
Yaohua Li, An-Ning Xu, Long-Gang Huang, Yong-Chun Liu
Summary: In this study, a detuning-switched method is proposed to generate strong and stationary mechanical squeezing quickly. The pulsed driving can transform optomechanical coupling into a linear optical force and maintain the effective mechanical frequency, resulting in strong mechanical squeezing within a short period of time. Moreover, the obtained strong mechanical squeezing can be frozen by increasing the pulse intervals, leading to stationary mechanical squeezing with a fixed squeezing angle. Therefore, our research provides fascinating insights and applications of modulated optomechanical systems.
Article
Optics
Xinyao Huang, Yong -Chun Liu
Summary: Realizing nonreciprocal transmission with low insertion loss and high contrast simultaneously is in great demand. We propose a generic approach to achieve perfect nonreciprocity by engineering energy losses. The interference between the direct and indirect transmission channels can be tuned to achieve 100% nonreciprocity contrast and zero insertion loss. Furthermore, our scheme allows a wide bandwidth nonreciprocity response by increasing the losses while maintaining perfect nonreciprocity at resonance.
Article
Optics
An-Ning Xu, Yong-Chun Liu
Summary: This study investigates the improvement of optomechanical precision measurements by tuning the optomechanical interaction without using squeezed light source. The tuning of mechanical susceptibility using optical force enhances the measurement sensitivity and broadens the working bandwidth. This approach provides a new avenue for significant improvement to optomechanical precision-measurement systems.
Review
Nanoscience & Nanotechnology
Bei-Bei Li, Lingfeng Ou, Yuechen Lei, Yong-Chun Liu
Summary: Cavity optomechanical systems enable interactions between light and mechanical resonators for fundamental physics and practical precision sensing applications. The resonant enhancement of mechanical and optical response in these systems allows for precise sensing of various physical quantities. Progress has been made in utilizing quantum techniques, especially squeezed light, to enhance the performance of optomechanical sensors.
