We theoretically investigate the quantum states of a Hamiltonian model for quasi-one-dimensional ultracold trapped gases. From the ansatz given by the numerical solution of the Schrödinger equation of the sys...We theoretically investigate the quantum states of a Hamiltonian model for quasi-one-dimensional ultracold trapped gases. From the ansatz given by the numerical solution of the Schrödinger equation of the system, we develop a scattering potential functional form and an approximate solution for the analytical approach of the model. We obtain the set of approximate eigenstates and eigenenergies that can be used in future improvements on the study of atomic scattering in low dimensional ultracold gases. We also show that there is a parity inversion of the ground state of the model as the interaction strength increases.展开更多
We present a new method to identify the critical point for the Bose-Einstein condensation (BEC) of a trapped Bose gas. We calculate the momentum distribution of an interacting Bose gas near the critical temperature,...We present a new method to identify the critical point for the Bose-Einstein condensation (BEC) of a trapped Bose gas. We calculate the momentum distribution of an interacting Bose gas near the critical temperature, and find that it deviates significantly from the Gaussian profile as the temperature approaches the critical point. More importantly, the standard deviation between the calculated momentum spectrum and the Gaussian profile at the same temperature shows a turning point at the critical point, which can be used to determine the critical temperature. These predictions are also confirmed by our BEC experiment for magnetically trapped ST Rb gases.展开更多
The Sulagiri meteorite fell in India on 12 September 2008,LL6 chondrite class is the largest among all the Indian meteorites.Isotopic compositions of noble gases(He,Ne,Ar,Kr and Xe) and nitrogen in the Sulagiri mete...The Sulagiri meteorite fell in India on 12 September 2008,LL6 chondrite class is the largest among all the Indian meteorites.Isotopic compositions of noble gases(He,Ne,Ar,Kr and Xe) and nitrogen in the Sulagiri meteorite and cosmic ray exposure history are discussed.Low cosmogenic(22Ne/21Ne)c ratio is consistent with irradiation in a large body.Cosmogenic noble gases indicate that Sulagiri has a 4πcosmic-ray exposure(CRE) age of 27.9 ± 3.4 Ma and is a member of the peak of CRE age distribution of IX chondrites.Radiogenic 4He and 40Ar concentrations in Sulagiri yields the radiogenic ages as 2.29 and4.56 Ca,indicating the loss of He from the meteorite.Xenon and krypton are mixture of Q and spallogenic components.展开更多
Accurately measuring magnetic fields is essential for magnetic-field sensitive experiments in areas like atomic,molecular,and optical physics,condensed matter experiments,and other areas.However,since many experiments...Accurately measuring magnetic fields is essential for magnetic-field sensitive experiments in areas like atomic,molecular,and optical physics,condensed matter experiments,and other areas.However,since many experiments are often conducted in an isolated environment that is inaccessible to experimentalists,it can be challenging to accurately determine the magnetic field at the target location.Here,we propose an efficient method for detecting magnetic fields with the assistance of an artificial neural network(NN).Instead of measuring the magnetic field directly at the desired location,we detect fields at several surrounding positions,and a trained NN can accurately predict the magnetic field at the target location.After training,we achieve a below 0.3%relative prediction error of magnetic field magnitude at the center of the vacuum chamber,and successfully apply this method to our erbium quantum gas apparatus for accurate calibration of magnetic field and long-term monitoring of environmental stray magnetic field.The demonstrated approach significantly simplifies the process of determining magnetic fields in isolated environments and can be applied to various research fields across a wide range of magnetic field magnitudes.展开更多
We discuss the possible nonlinear waves of atomic matter wave in a Bose-Einstein condensate. One and two of two-dimensional (2D) dark solitons in the Bose-Einstein condensed system are investigated. A rich dynamics ...We discuss the possible nonlinear waves of atomic matter wave in a Bose-Einstein condensate. One and two of two-dimensional (2D) dark solitons in the Bose-Einstein condensed system are investigated. A rich dynamics is studied for the interactions between two solitons. The interaction profiles of two solitons are greatly different if the angle between them are different. If the angle is small enough, the maximum amplitude during the interaction between two solitons is even less than that of a single soliton. However, if the angle is large enough, the maximum amplitude of two solitons can gradually attend to the sum of two soliton amplitudes.展开更多
We derive the coupled nonpolynomial nonlinear Schr6dinger equations for a two-component Bose-Lmstem conaensate in a quasi-one-dimension geometry and investigate the effects of a tightly transverse trapping on the grou...We derive the coupled nonpolynomial nonlinear Schr6dinger equations for a two-component Bose-Lmstem conaensate in a quasi-one-dimension geometry and investigate the effects of a tightly transverse trapping on the ground state and the miscibility-immiscibility threshold. We find that the density profile of the matter wavepacket is remarkably dependent on the transverse width and the effective one-dimension nonlinear coupling strengths in miscible and immiscible regimes.展开更多
The possibilities of changes of ORP (oxidation-reduction water potential) with the help of chemical and physical-chemical methods were explored. Distillation and membrane technology were used as physical-chemical me...The possibilities of changes of ORP (oxidation-reduction water potential) with the help of chemical and physical-chemical methods were explored. Distillation and membrane technology were used as physical-chemical methods. In the case of application of chemical methods well-soluble substances were added into water. It was ascertained that the application of membrane technology makes it possible to obtain antioxidant water with negative ORR. Different energy change in a time unit can be applied in a whole number of technological processes and reveals new possibilities for many branches of industry.展开更多
基金thank financial support from CNPq,FAPEMIG and CAPES(Brazilian funding agencies).
文摘We theoretically investigate the quantum states of a Hamiltonian model for quasi-one-dimensional ultracold trapped gases. From the ansatz given by the numerical solution of the Schrödinger equation of the system, we develop a scattering potential functional form and an approximate solution for the analytical approach of the model. We obtain the set of approximate eigenstates and eigenenergies that can be used in future improvements on the study of atomic scattering in low dimensional ultracold gases. We also show that there is a parity inversion of the ground state of the model as the interaction strength increases.
基金Supported by the National Natural Science Foundation of China under Grant No 11104322the National Key Basic Research and Development Program of China under Grant No 2011CB921503
文摘We present a new method to identify the critical point for the Bose-Einstein condensation (BEC) of a trapped Bose gas. We calculate the momentum distribution of an interacting Bose gas near the critical temperature, and find that it deviates significantly from the Gaussian profile as the temperature approaches the critical point. More importantly, the standard deviation between the calculated momentum spectrum and the Gaussian profile at the same temperature shows a turning point at the critical point, which can be used to determine the critical temperature. These predictions are also confirmed by our BEC experiment for magnetically trapped ST Rb gases.
文摘The Sulagiri meteorite fell in India on 12 September 2008,LL6 chondrite class is the largest among all the Indian meteorites.Isotopic compositions of noble gases(He,Ne,Ar,Kr and Xe) and nitrogen in the Sulagiri meteorite and cosmic ray exposure history are discussed.Low cosmogenic(22Ne/21Ne)c ratio is consistent with irradiation in a large body.Cosmogenic noble gases indicate that Sulagiri has a 4πcosmic-ray exposure(CRE) age of 27.9 ± 3.4 Ma and is a member of the peak of CRE age distribution of IX chondrites.Radiogenic 4He and 40Ar concentrations in Sulagiri yields the radiogenic ages as 2.29 and4.56 Ca,indicating the loss of He from the meteorite.Xenon and krypton are mixture of Q and spallogenic components.
基金Project supported by the RGC of China(Grant Nos.16306119,16302420,16302821,16306321,16306922,C6009-20G,N-HKUST636-22,and RFS2122-6S04).
文摘Accurately measuring magnetic fields is essential for magnetic-field sensitive experiments in areas like atomic,molecular,and optical physics,condensed matter experiments,and other areas.However,since many experiments are often conducted in an isolated environment that is inaccessible to experimentalists,it can be challenging to accurately determine the magnetic field at the target location.Here,we propose an efficient method for detecting magnetic fields with the assistance of an artificial neural network(NN).Instead of measuring the magnetic field directly at the desired location,we detect fields at several surrounding positions,and a trained NN can accurately predict the magnetic field at the target location.After training,we achieve a below 0.3%relative prediction error of magnetic field magnitude at the center of the vacuum chamber,and successfully apply this method to our erbium quantum gas apparatus for accurate calibration of magnetic field and long-term monitoring of environmental stray magnetic field.The demonstrated approach significantly simplifies the process of determining magnetic fields in isolated environments and can be applied to various research fields across a wide range of magnetic field magnitudes.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10575082 and 10247008.
文摘We discuss the possible nonlinear waves of atomic matter wave in a Bose-Einstein condensate. One and two of two-dimensional (2D) dark solitons in the Bose-Einstein condensed system are investigated. A rich dynamics is studied for the interactions between two solitons. The interaction profiles of two solitons are greatly different if the angle between them are different. If the angle is small enough, the maximum amplitude during the interaction between two solitons is even less than that of a single soliton. However, if the angle is large enough, the maximum amplitude of two solitons can gradually attend to the sum of two soliton amplitudes.
基金supported by the National Natural Science Foundation of China (Grant No. 11104292)the National Basic Research Program of China (Grant No. 2011CB921504)
文摘We derive the coupled nonpolynomial nonlinear Schr6dinger equations for a two-component Bose-Lmstem conaensate in a quasi-one-dimension geometry and investigate the effects of a tightly transverse trapping on the ground state and the miscibility-immiscibility threshold. We find that the density profile of the matter wavepacket is remarkably dependent on the transverse width and the effective one-dimension nonlinear coupling strengths in miscible and immiscible regimes.
文摘The possibilities of changes of ORP (oxidation-reduction water potential) with the help of chemical and physical-chemical methods were explored. Distillation and membrane technology were used as physical-chemical methods. In the case of application of chemical methods well-soluble substances were added into water. It was ascertained that the application of membrane technology makes it possible to obtain antioxidant water with negative ORR. Different energy change in a time unit can be applied in a whole number of technological processes and reveals new possibilities for many branches of industry.