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Restoring cosmological concordance with axion-like early dark energy and dark matter characterized by a constant equation of state?

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Communications in Theoretical physics 2024年第7期76卷 76-84页

作者： Yan-Hong Yao Xin-He Meng school of physics and Astronomy Sun Yat-sen University school of physics Nankai University

The Hubble tension persists as a challenge in cosmology. Even early dark energy（EDE） models,initially considered the most promising for alleviating the Hubble tension, fall short of addressing the issue without exacerbating other tensions, such as the S8tension. Considering that a negative dark matter（DM） equation of state（EoS） parameter is conducive to reduce the value of the σ8parameter, we extend the axion-like EDE model in this paper by replacing the cold dark matter（CDM） with DM characterized by a constant EoS wdm（referred to as WDM hereafter）.We then impose constraints on this axion-like EDE extension model, along with three other models: the axion-like EDE model, ΛWDM, and ΛCDM. These constraints are derived from a comprehensive analysis incorporating data from the Planck 2018 cosmic microwave background, baryon acoustic oscillations, and the Pantheon compilation, as well as a prior on H0（i.e. H0= 73.04 ± 1.04, based on the latest local measurement by Riess et al） and a Gaussianized prior on S8（i.e. S8= 0.766 ± 0.017, determined through the joint analysis of KID1000+BOSS+2dLenS）. We find that although the new model maintains the ability to alleviate the Hubble tension to ～1.4σ, it still exacerbates the S8tension to a level similar to that of the axion-like EDE model.

关键词： early dark energy Hubble tension noncold dark matter S8 tension

Evolution of artificial ion channels

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National Science Review 2024年第1期11卷 72-73页

作者： Yugang Wang school of physics Peking University

Protein ion channels on a cell membrane generate action potentials for cellular signal transduction, and regulate biological activities during life. Since the discovery of the asymmetric ion transport phenomenon in quartz nanopipettes by Bard and colleagues [1], synthetic nanofluidic materials and devices have attracted a lot of research interests from the scientific community,

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Phenomenology of heavy neutral gauge boson at muon collider

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Science China(physics,Mechanics & Astronomy) 2024年第3期67卷 60-79页

作者： Zongyang Lu Honglei Li Zhi-Long Han Zong-Guo Si Liuxin Zhao school of physics and Technology University of JinanJinan 250022China school of physics Shandong UniversityJinan 250100China

Heavy neutral gauge boson Z' is proposed in many new physics *** has rich phenomena at the future muon *** study the properties of Z' boson with the process of μ^(+)μ^(-)→qq,μ^(+)μ^(-)→l^(+)l^(-),μ^(+)μ^(-)→ ZH and μ^(+)μ^(-)→ W^(+)W^(-).The discrepancy of Z' coupling to different types of particles can be shown in the cross section distributions around the resonance peak of various decay *** distributions of the final quark or lepton in μ^(+)μ^(-)→qq/l^(+)l^(-)process are sensitive to the parameters such as mass of Z' and the Z-Z' mixing *** interaction of new gauge boson coupling to the standard model gauge particles and Higgs boson are also studied through μ^(+)μ^(-)→ ZH→l^(+)l^(-)bb and μ^(+)u^(-)→ W^(+)W^(-)→l^(+)l^(-)v_(l)v_(l).The cross section and the final particles' angular distributions with the contribution of Z' boson differ from those processes with only standard model particles.A forward-backward asymmetry defined by the angular distribution is provided to show the potential of searching for new physics at the muon ***,the beam polarization with certain value can effectively enlarge the forward-backward asymmetry.

关键词： Z′boson muon collider new physics

Hole-Doped Nonvolatile and Electrically Controllable Magnetism in van der Waals Ferroelectric Heterostructures

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Chinese physics Letters 2024年第5期41卷 107-119页

作者：姜新新王智宽李冲孙雪莲杨磊李冬梅崔彬刘德胜 school of physics National Demonstration Center for Experimental Physics EducationShandong UniversityJinan 250100China school of physics and Microelectronics Zhengzhou UniversityZhengzhou 450001China

Electrical control of magnetism in van der Waals semiconductors is a promising step towards development of two-dimensional spintronic devices with ultralow power consumption for processing and storing ***, we propose a design for two-dimensional van der Waals heterostructures(vdWHs) that can host ferroelectricity and ferromagnetism simultaneously under hole doping. By contacting an In Se monolayer and forming an InSe/In_(2)Se_(3) vd WH, the switchable built-in electric field from the reversible out-of-plane polarization enables robust control of the band alignment. Furthermore, switching between the two ferroelectric states(P_↑ and P_↓)of hole-doped In_(2)Se_(3) with an external electric field can interchange the ON and OFF states of the nonvolatile magnetism. More interestingly, doping concentration and strain can effectively tune the magnetic moment and polarization energy. Therefore, this provides a platform for realizing multiferroics in ferroelectric heterostructures,showing great potential for use in nonvolatile memories and ferroelectric field-effect transistors.

关键词： polarization ferroelectric doping

Study on Coded Permutation Entropy of Finite Length Gaussian White Noise Time Series

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Chinese Journal of Electronics 2024年第1期33卷 185-194页

作者： Huihui SUN Xiaofeng ZHANG school of physics and Information Technology Shaanxi Normal University

As an extension of permutation entropy(PE), coded permutation entropy(CPE) improves the performance of PE by making a secondary division for ordinal patterns defined in PE. In this study, we provide an exploration of the statistical properties of CPE using a finite length Gaussian white noise time series theoretically. By means of the Taylor series expansion, the approximate expressions of the expected value and variance of CPE are deduced and the Cramér-Rao low bound(CRLB) is obtained to evaluate the performance of the CPE estimator. The results indicate that CPE is a biased estimator, but the bias only depends on relevant parameters of CPE and it can be easily corrected for an arbitrary time series. The variance of CPE is related to the encoding patterns distribution,and the value converges to the CRLB of the CPE estimator when the time series length is large enough. For a finitelength Gaussian white noise time series model, the predicted values can match well with the actual values, which further validates the statistic theory of CPE. Using the theoretical expressions of CPE, it is possible to better understand the behavior of CPE for most of the time series.

关键词： Time series analysis White noise Predictive models Taylor series Entropy Encoding Time measurement

Test of the Brans–Dicke theory with GW200105 and GW200115

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Communications in Theoretical physics 2024年第7期76卷 85-95页

作者： Qin Fei Yingjie Yang Department of Mathematics and physics School of Biomedical Engineering Southern Medical University school of Mathematics and physics Hubei Polytechnic University

We study whether it is possible to constrain the Brans–Dicke（BD） theory from the measurement of gravitational waves（GW） released in neutron star-black hole collisions. Considering the scalar field modifications through monopole and dipole radiations, we find additional contributions to the phase evolution in the emitted gravitational waveform. After effectively calculating such effect in the post-Newtonian order, we are in a position to measure the scalar field and give bounds on the BD coupling parameter ωBD. We derive the analytical expression for the phase modification due to the orbital eccentricity of eccentric binaries in both general relativity and BD theory. Employing the Bayesian analysis, we obtain the constraints on ωBDfrom the GW events, GW200105 and GW200115.

关键词： Brans-Dicke theory cosmology gravitational wave

Nonadiabatic Holonomic Quantum Computation Based on Rydberg Ground State Blockade

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Chinese physics Letters 2024年第4期41卷 25-31页

作者：苏石磊王琛宋佩瑶陈刚 school of physics Zhengzhou UniversityZhengzhou 450001China

Quantum gates are crucial for quantum computation and quantum information processing. However, their effectiveness is often hindered by systematic errors and decoherence. Therefore, achieving resilient quantum gates to these factors is of great significance. We present a method to construct nonadiabatic holonomic single-and two-qubit gates in a Rydberg ground-state-blockade regime. Our approach utilizes a far-off-resonant technique for the single-qubit gate and a modified Rydberg antiblockade for the two-qubit gate. The reduction of the population of single-and two-excitation Rydberg states and the nonadiabatic holonomic process during the construction of the gates ensure robustness to decoherence and systematic errors, respectively. Numerical results demonstrate the fidelity and robustness of our scheme. The proposed scheme holds promise for future applications in quantum computation and quantum information processing tasks.

关键词： Rydberg quantum holds

Effect of cognitive training on brain dynamics

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Chinese physics B 2024年第2期33卷 529-536页

作者：吕贵阳徐天勇陈飞燕朱萍王淼何国光 school of physics Zhejiang UniversityHangzhou 310027China

The human brain is highly *** training is usually used to modify functional connectivity of brain ***,the structures of brain networks may determine its dynamic behavior which is related to human cognitive *** study the effect of functional connectivity on the brain dynamics,the dynamic model based on functional connections of the brain and the Hindmarsh–Rose model is utilized in this *** resting-state fMRI data from the experimental group undergoing abacus-based mental calculation(AMC)training and from the control group are used to construct the functional brain *** dynamic behavior of brain at the resting and task states for the AMC group and the control group are simulated with the above-mentioned dynamic *** the resting state,there are the differences of brain activation between the AMC group and the control group,and more brain regions are inspired in the AMC group.A stimulus with sinusoidal signals to brain networks is introduced to simulate the brain dynamics in the task *** dynamic characteristics are extracted by the excitation rates,the response intensities and the state *** change in the functional connectivity of brain networks with the AMC training would in turn improve the brain response to external stimulus,and make the brain more efficient in processing tasks.

关键词： brian dynamics functional brain networks cognitive training abacus-based mental calculation

Entropy of deterministic trajectory via trajectories ensemble

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Chinese physics B 2024年第6期33卷 347-354页

作者：彭勇刚冉翠平郑雨军 school of physics Shandong UniversityJinan 250100China

We present a formulation of the single-trajectory entropy using the trajectories ensemble. The single-trajectory entropy is affected by its surrounding trajectories via the distribution function. The single-trajectory entropies are studied in two typical potentials, i.e., harmonic potential and double-well potential, and in viscous environment by interacting trajectory method. The results of the trajectory methods are in agreement well with the numerical methods(Monte Carlo simulation and difference equation). The single-trajectory entropies increasing(decreasing) could be caused by absorption(emission) heat from(to) the thermal environment. Also, some interesting trajectories, which correspond to the rare evens in the processes, are demonstrated.

关键词： trajectory entropy trajectories ensemble