This paper proposes a scheme of axial triple-well optical dipole trap by employing a simple optical system composed of a circular cosine grating and a lens. Three optical wells separated averagely by -37 μm were crea...This paper proposes a scheme of axial triple-well optical dipole trap by employing a simple optical system composed of a circular cosine grating and a lens. Three optical wells separated averagely by -37 μm were created when illuminating by a YAG laser with power 1 mW. These wells with average trapping depth -0.5 μK and volume -74 μm^3 are suitable to trap and manipulate an atomic Bose-Einstein condensation （BEC）. Due to a controllable grating implemented by a spatial light modulator, an evolution between a triple-well trap and a single-well one is achievable by adjusting the height of potential barrier between adjacent wells. Based on this novel triple-well potentials, the loading and splitting of BEC, as well as the interference between three freely expanding BECs, are also numerically stimulated within the framework of mean-field treatment. By fitting three cosine functions with three Gaussian envelopes to interference fringe, the information of relative phases among three condensates is extracted.展开更多
An extended variation approach to describing the dynamic evolution of self-attractive Bose-Einstein condensates is developed. We consider bright matter-wave solitons in the presence of a parabolic magnetic potential a...An extended variation approach to describing the dynamic evolution of self-attractive Bose-Einstein condensates is developed. We consider bright matter-wave solitons in the presence of a parabolic magnetic potential and a timespace periodic optical lattice. The dynamics of condensates is shown to be well approximated by four coupled nonlinear differential equations. A noteworthy feature is that the extended variation approach gives a critical strength ratio to support multiple stable lattice sites for the condensate. We further examine the existence of the solitons and their stabilities at the multiple stable lattice sites. In this case, the analytical predictions of Bose-Einstein condensates variational dynamics are found to be in good agreement with numerical simulations. We then find a stable region for successful manipulating matter-wave solitons without collapse, which are dragged from an initial stationary to a prescribed position by a moving periodic optical lattice.展开更多
We investigate the moving matter-wave solitons in spin-orbit coupled Bose Einstein condensates （BECs） by a perturbation method. Starting with the one-dimensional Gross Pitaevskii equations, we derive a new KdV-like ...We investigate the moving matter-wave solitons in spin-orbit coupled Bose Einstein condensates （BECs） by a perturbation method. Starting with the one-dimensional Gross Pitaevskii equations, we derive a new KdV-like equation to which an approximate solution is obtained by assuming weak Raman coupling and strong spin orbit coupling. The derivation of the KdV-like equation may be useful to understand the properties of solitons excitation in spin-orbit coupled BECs. We find different types of moving solitons： dark-bright, bright bright and dark dark solitons. Interestingly, moving dark-dark soliton for attractive intra- and inter-species interactions is found, which depends on the Raman coupling. The amplitude and velocity of the moving solitons strongly depend on the Raman coupling and spin orbit coupling.展开更多
We investigate the stability and collision dynamics of dissipative matter-wave solitons formed in a quasi-one- dimensional Bose-Einstein condensate with linear gain and three-body recombination loss perturbed by a wea...We investigate the stability and collision dynamics of dissipative matter-wave solitons formed in a quasi-one- dimensional Bose-Einstein condensate with linear gain and three-body recombination loss perturbed by a weak optical lattice. It is shown that the linear gain can modify the stability of the single dissipative soliton moving in the optical lattice. The collision dynamics of two individual dissipative matter-wave solitons explicitly depend on the linear gain parameter, and they display different dynamical behaviors in both the in-phase and out-of-phase interaction regimes.展开更多
Using the F-expansion method we present analytical matter-wave solutions to Bose-Einstein condensates with two- and three-body interactions through the generalized three-dimensional Gross-Pitaevskii equation with time...Using the F-expansion method we present analytical matter-wave solutions to Bose-Einstein condensates with two- and three-body interactions through the generalized three-dimensional Gross-Pitaevskii equation with time- dependent coefficients, for the periodically time-varying interactions and quadratic potential strength. Such solutions exist under certain conditions, and impose constraints on the functions describing potential strength, nonlinearities, and gain （loss）. Various shapes of analytical matter-wave solutions which have important applications of physical interest are s^udied in details.展开更多
We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of...We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of these solitons in Bose-Einstein condensate8 （BECs） by some selected control functions. Our results show that the intensities of these solitons first increase rapidly to the condensation peak, then decay very slowly to the background; thus the lifetime of a bright soliton, a train of bright solitons and a dark soliton in BECs can be all greatly extended. Our results offer a useful method for observing matter-wave solitons in BECs in future experiments.展开更多
We present three families of exact matter-wave soliton solutions for an effective one-dimension twocomponent Bose-Einstein condensates(BECs) with tunable interactions,harmonic potential and gain or loss term. We inves...We present three families of exact matter-wave soliton solutions for an effective one-dimension twocomponent Bose-Einstein condensates(BECs) with tunable interactions,harmonic potential and gain or loss term. We investigate the dynamics of bright-bright solitons,bright-dark solitons and dark-dark solitons for the time-dependent expulsive harmonic trap potential,periodically modulated harmonic trap potential,and kinklike modulated harmonic trap potential.Through the Feshbach resonance,these dynamics can be realized in experiments by suitable control of time-dependent trap parameters,atomic interactions,and interaction with thermal cloud.展开更多
We study two-dimensional （2D） matter-wave solitons in the mean-field models formed by electric quadrupole particles with long-range quadrupoleluadrupole interaction （QQI） in 2D free space. The existence of 2D matt...We study two-dimensional （2D） matter-wave solitons in the mean-field models formed by electric quadrupole particles with long-range quadrupoleluadrupole interaction （QQI） in 2D free space. The existence of 2D matter-wave solitons in the free space was predicted using the 2D Gross Pitaevskii Equation （GPE）. We find that the QQI solitoms have a higher mass （smaller size and higher intensity） and stronger anisotropy than the dipol^dipole interaction （DDI） solitons under the same environmental parameters. Anisotropic solitomsoliton interaction between two identical QQI solitons in 2D free space is studied. Moreover, stable anisotropic dipole solitons are observed, to our knowledge, for the first time in 2D free space under anisotropic nonlocal cubic nonlinearity.展开更多
We study the spontaneous symmetry breaking of dipolar Bose-Einstein condensates trapped in stacks of two-well systems, which may be effectively built as one-dimensional trapping lattices sliced by a repelling laser sh...We study the spontaneous symmetry breaking of dipolar Bose-Einstein condensates trapped in stacks of two-well systems, which may be effectively built as one-dimensional trapping lattices sliced by a repelling laser sheet. If the potential wells are sufficiently deep, the system is modeled by coupled discrete Gross-Pitaevskii equations with nonlocal self- and cross-interaction terms representing dipole-dipole interactions. When the dipoles are not polarized perpendicular or parallel to the lattice, the cross- interaction is asymmetric, replacing the familiar symmetric two-component solitons with a new species of cross-symmetric or -asymmetric ones. The orientation of the dipole moments and the interwell hopping rate strongly affect the shapes of the discrete two-component solitons as well as the characteristics of the cross-symmetry breaking and the associated phase transition. The sub- and super-critical types of cross-symmetry breaking can be controlled by either the hopping rate between the components or the total norm of the solitons. The effect of the interplay between the contact nonlinearity and the dipole angle on the cross-symmetry breaking is also discussed.展开更多
目的探讨心电图P波参数与脑白质病变(white matter lesions,WMLs)严重程度之间的关联,为WMLs的预防和治疗提供科学依据。方法选取289例符合入组标准的WMLs住院患者作为研究对象,其均接受常规12导联心电图和头颅磁共振成像检查。根据Faze...目的探讨心电图P波参数与脑白质病变(white matter lesions,WMLs)严重程度之间的关联,为WMLs的预防和治疗提供科学依据。方法选取289例符合入组标准的WMLs住院患者作为研究对象,其均接受常规12导联心电图和头颅磁共振成像检查。根据Fazekas量表评分将这些患者分为无-轻度组(158例)和中-重度组(131例)。收集两组患者的临床资料、既往病史、心电图P波参数[包括P波时限、P波电轴、V_(1)导联P波终末电势(terminal force of P-wave in lead V_(1),PTFV_(1))],以及血脂等数据,并进行比较分析。采用Logistic回归模型分析影响WMLs的独立危险因素。结果中-重度组患者的年龄、有高血压或糖尿病病史者占比及PTFV_(1)>4000μV·ms者占比均明显高于无-轻度组,且差异均有统计学意义(均P<0.01)。多变量Logistic回归分析表明,年龄增长、高血压、糖尿病以及PTFV_(1)>4000μV·ms均为WMLs的独立危险因素。结论无创心电图指标PTFV_(1)经济便捷、易于获取,可用于评估心房异常,对WMLs的防治具有一定的应用价值。展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos.10434060,10674047 and 10804031)the National Key Basic Research and Development Program of China (Grant No.2006CB921604)+2 种基金the Program for Changjiang Scholarand Innovative Research Team and Shanghai Leading Academic Discipline Project (Grant No.B408)the Youth Foundation of Jiangxi Educational Committee (Grant No.GJJ09530)the Scientific Research Foundation of ECIT (Grant No.DSH0417)
文摘This paper proposes a scheme of axial triple-well optical dipole trap by employing a simple optical system composed of a circular cosine grating and a lens. Three optical wells separated averagely by -37 μm were created when illuminating by a YAG laser with power 1 mW. These wells with average trapping depth -0.5 μK and volume -74 μm^3 are suitable to trap and manipulate an atomic Bose-Einstein condensation （BEC）. Due to a controllable grating implemented by a spatial light modulator, an evolution between a triple-well trap and a single-well one is achievable by adjusting the height of potential barrier between adjacent wells. Based on this novel triple-well potentials, the loading and splitting of BEC, as well as the interference between three freely expanding BECs, are also numerically stimulated within the framework of mean-field treatment. By fitting three cosine functions with three Gaussian envelopes to interference fringe, the information of relative phases among three condensates is extracted.
基金supported by the National Natural Science Foundation of China (Grant Nos.10672147 and 11072219)the Natural Science Foundation of Zhejiang Province,China (Grant Nos.Y605312 and Y1080959)the Foundation of Department of Education of Zhejiang Province,China (Grant No.20030704)
文摘An extended variation approach to describing the dynamic evolution of self-attractive Bose-Einstein condensates is developed. We consider bright matter-wave solitons in the presence of a parabolic magnetic potential and a timespace periodic optical lattice. The dynamics of condensates is shown to be well approximated by four coupled nonlinear differential equations. A noteworthy feature is that the extended variation approach gives a critical strength ratio to support multiple stable lattice sites for the condensate. We further examine the existence of the solitons and their stabilities at the multiple stable lattice sites. In this case, the analytical predictions of Bose-Einstein condensates variational dynamics are found to be in good agreement with numerical simulations. We then find a stable region for successful manipulating matter-wave solitons without collapse, which are dragged from an initial stationary to a prescribed position by a moving periodic optical lattice.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11274255,11305132 and 11475027the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No 20136203110001the Creation of Science and Technology of Northwest Normal University of China under Grant Nos NWNU-KJCXGC-03-48,NWNULKQN-12-12 and NWNU-LKQN-10-27
文摘We investigate the moving matter-wave solitons in spin-orbit coupled Bose Einstein condensates （BECs） by a perturbation method. Starting with the one-dimensional Gross Pitaevskii equations, we derive a new KdV-like equation to which an approximate solution is obtained by assuming weak Raman coupling and strong spin orbit coupling. The derivation of the KdV-like equation may be useful to understand the properties of solitons excitation in spin-orbit coupled BECs. We find different types of moving solitons： dark-bright, bright bright and dark dark solitons. Interestingly, moving dark-dark soliton for attractive intra- and inter-species interactions is found, which depends on the Raman coupling. The amplitude and velocity of the moving solitons strongly depend on the Raman coupling and spin orbit coupling.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11547125 and 11465008the Hunan Provincial Natural Science Foundation under Grant Nos 2015JJ4020 and 2015JJ2114the Scientific Research Fund of Hunan Provincial Education Department under Grant No 14A118
文摘We investigate the stability and collision dynamics of dissipative matter-wave solitons formed in a quasi-one- dimensional Bose-Einstein condensate with linear gain and three-body recombination loss perturbed by a weak optical lattice. It is shown that the linear gain can modify the stability of the single dissipative soliton moving in the optical lattice. The collision dynamics of two individual dissipative matter-wave solitons explicitly depend on the linear gain parameter, and they display different dynamical behaviors in both the in-phase and out-of-phase interaction regimes.
基金Supported by the National Natural Science Foundation of China under Grant No.11105057the Foundation of Hubei University of Education under Grant No.2009B013the Project of Excellent Teacher Team of Hubei University of Education under Grant No.2012KB302
文摘Using the F-expansion method we present analytical matter-wave solutions to Bose-Einstein condensates with two- and three-body interactions through the generalized three-dimensional Gross-Pitaevskii equation with time- dependent coefficients, for the periodically time-varying interactions and quadratic potential strength. Such solutions exist under certain conditions, and impose constraints on the functions describing potential strength, nonlinearities, and gain （loss）. Various shapes of analytical matter-wave solutions which have important applications of physical interest are s^udied in details.
基金Supported by NSFC under Grant Nos. 11041003, 10735030, 10874235, 10934010, 60978019, the NKBRSFC under Grant Nos. 2009CB930701, 2010CB922904, and 2011CB921500Zhejiang Provincial NSF under Grant No. Y6090592+1 种基金Ningbo Natural Science Foundation under Grant Nos. 2010A610095, 2010A610103, and 2009B21003K.C. Wong Magna Fund in Ningbo University
文摘We present three families of one-soliton solutions for （2＋1）-dimensional Gross-Pitaevskii equation with both time-dependent scattering length and gain or loss in a harmonic trap. Then we investigate the dynamics of these solitons in Bose-Einstein condensate8 （BECs） by some selected control functions. Our results show that the intensities of these solitons first increase rapidly to the condensation peak, then decay very slowly to the background; thus the lifetime of a bright soliton, a train of bright solitons and a dark soliton in BECs can be all greatly extended. Our results offer a useful method for observing matter-wave solitons in BECs in future experiments.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11041003 and 60802087the Natural Science Foundation of Jiangsu Province under Grant No.BK2004119
文摘We present three families of exact matter-wave soliton solutions for an effective one-dimension twocomponent Bose-Einstein condensates(BECs) with tunable interactions,harmonic potential and gain or loss term. We investigate the dynamics of bright-bright solitons,bright-dark solitons and dark-dark solitons for the time-dependent expulsive harmonic trap potential,periodically modulated harmonic trap potential,and kinklike modulated harmonic trap potential.Through the Feshbach resonance,these dynamics can be realized in experiments by suitable control of time-dependent trap parameters,atomic interactions,and interaction with thermal cloud.
文摘We study two-dimensional （2D） matter-wave solitons in the mean-field models formed by electric quadrupole particles with long-range quadrupoleluadrupole interaction （QQI） in 2D free space. The existence of 2D matter-wave solitons in the free space was predicted using the 2D Gross Pitaevskii Equation （GPE）. We find that the QQI solitoms have a higher mass （smaller size and higher intensity） and stronger anisotropy than the dipol^dipole interaction （DDI） solitons under the same environmental parameters. Anisotropic solitomsoliton interaction between two identical QQI solitons in 2D free space is studied. Moreover, stable anisotropic dipole solitons are observed, to our knowledge, for the first time in 2D free space under anisotropic nonlocal cubic nonlinearity.
基金Acknowledgements Tile authors appreciate the very useful discussion with Prof. Boris A. Malomed. This work was supported by the National Natural Science Foundation of China under Grant Nos. 11575063, 61471123, and 61575041, and the Natural Science Foundation of Guangdong Province under Grant No. 2015A030313639.
文摘We study the spontaneous symmetry breaking of dipolar Bose-Einstein condensates trapped in stacks of two-well systems, which may be effectively built as one-dimensional trapping lattices sliced by a repelling laser sheet. If the potential wells are sufficiently deep, the system is modeled by coupled discrete Gross-Pitaevskii equations with nonlocal self- and cross-interaction terms representing dipole-dipole interactions. When the dipoles are not polarized perpendicular or parallel to the lattice, the cross- interaction is asymmetric, replacing the familiar symmetric two-component solitons with a new species of cross-symmetric or -asymmetric ones. The orientation of the dipole moments and the interwell hopping rate strongly affect the shapes of the discrete two-component solitons as well as the characteristics of the cross-symmetry breaking and the associated phase transition. The sub- and super-critical types of cross-symmetry breaking can be controlled by either the hopping rate between the components or the total norm of the solitons. The effect of the interplay between the contact nonlinearity and the dipole angle on the cross-symmetry breaking is also discussed.
文摘目的探讨心电图P波参数与脑白质病变(white matter lesions,WMLs)严重程度之间的关联,为WMLs的预防和治疗提供科学依据。方法选取289例符合入组标准的WMLs住院患者作为研究对象,其均接受常规12导联心电图和头颅磁共振成像检查。根据Fazekas量表评分将这些患者分为无-轻度组(158例)和中-重度组(131例)。收集两组患者的临床资料、既往病史、心电图P波参数[包括P波时限、P波电轴、V_(1)导联P波终末电势(terminal force of P-wave in lead V_(1),PTFV_(1))],以及血脂等数据,并进行比较分析。采用Logistic回归模型分析影响WMLs的独立危险因素。结果中-重度组患者的年龄、有高血压或糖尿病病史者占比及PTFV_(1)>4000μV·ms者占比均明显高于无-轻度组,且差异均有统计学意义(均P<0.01)。多变量Logistic回归分析表明,年龄增长、高血压、糖尿病以及PTFV_(1)>4000μV·ms均为WMLs的独立危险因素。结论无创心电图指标PTFV_(1)经济便捷、易于获取,可用于评估心房异常,对WMLs的防治具有一定的应用价值。
