Interactions between atoms in ultracold quantum gases play an important role in the study of the quantum simulation of many-body physics.Feshbach resonance is a versatile tool to control atomic interactions,where the ...Interactions between atoms in ultracold quantum gases play an important role in the study of the quantum simulation of many-body physics.Feshbach resonance is a versatile tool to control atomic interactions,where the atom-loss spectra are widely used to characterize Feshbach resonances of various atomic species.Here,we report the experimental observation of momentum-induced broadening of widths in atom-loss spectra of narrow ^(133)Cs Feshbach resonances.We drive Bragg excitation to kick the Bose-Einstein condensate of Cs atoms in a cigar-shaped optical trap,and measure the atom-loss spectra of narrow Feshbach resonances of moving ultracold atoms near the magnetic fields 19.84 G and 47.97 G.We show that the widths of the atom-loss spectra are broadened for the atoms with the momenta of 2hk,and 4hk,and even observe splitting in the Feshbach resonance of the atoms with momentum 4hk.Our work may open the way for exploring the interesting physical phenomena arising from the collective velocity of colliding atoms that have been ignored in general.展开更多
We report the experimental preparations of the absolute ground states of 87Rb and 40K atoms （｜F = 1, mF = 1 ） ＋ ｜F = 9/2, rnF ： -9/2）） by means of the radio-frequency and microwave adiabatic rapid passages, an...We report the experimental preparations of the absolute ground states of 87Rb and 40K atoms （｜F = 1, mF = 1 ） ＋ ｜F = 9/2, rnF ： -9/2）） by means of the radio-frequency and microwave adiabatic rapid passages, and the observation of magnetic Feshbach resonances in an ultracold mixture of bosonic STRb and fermionic 40K atoms between 0 T and 6.0 × 10^-2 T, including 7 homonuclear and 4 heteronuclear Feshbach resonances. The resonances are identified by the abrupt trap loss of atoms induced by the strong inelastic three-body collisions. These Feshbach resonances should enable the experimental control of interspecies interactions.展开更多
We present an intensive study of the coupling between different Feshbach states and the hyperfine levels of the excited states in the adiabatic creation of^(23)Na^(40)K ground-state molecules.We use coupled-channel me...We present an intensive study of the coupling between different Feshbach states and the hyperfine levels of the excited states in the adiabatic creation of^(23)Na^(40)K ground-state molecules.We use coupled-channel method to calculate the wave function of the Feshbach molecules,and give the short-range wave function of triplet component.The energies of the hyperfine excited states and the coupling strength between the Feshbach states and the hyperfine excited states are calculated.Our results can be used to prepare a specific hyperfine level of the rovibrational ground state to study the ultracold collisions involving molecules.展开更多
By using Darboux transformation, this paper studies analytically the nonlinear dynamics of a one-dimensional growing Bose-Einstein condensate （BEC）. It is shown that the growing model has an important effect on the ...By using Darboux transformation, this paper studies analytically the nonlinear dynamics of a one-dimensional growing Bose-Einstein condensate （BEC）. It is shown that the growing model has an important effect on the amplitude of the soliton in the condensates. In the absence of the growing model, there exhibits the stable alternate bright solitons in the condensates. In the presence of the growing model, the obtained results show that the amplitude of the bright soliton decreases （increases） for the BEC growing coefficient Ω 〈 0 （Ω 〉 0）. Furthermore, we propose experimental protocols to manipulate the amplitude of the bright soliton by varying the scattering length via the Feshbach resonance in the future experiment.展开更多
We investigate the two-color laser modulation of the magnetically induced Feshbach resonance. The two-color laser is nearly resonant with an optical bound-to-bound transition at the resonance position. The analytical ...We investigate the two-color laser modulation of the magnetically induced Feshbach resonance. The two-color laser is nearly resonant with an optical bound-to-bound transition at the resonance position. The analytical formula of scattering length is obtained by solving the Heisenberg equation. The scattering length can be modified by changing the Rabi frequencies or optical field frequency. By choosing the suitable optical parameters, the two-body loss coefficient K2 can be greatly reduced compared to the usual single optical scheme.展开更多
We present a detailed analysis of near zero-energy Feshbach resonances in ultracold collisions of atom and molecule,taking the He–PH system as an example, subject to superimposed electric and magnetic static fields. ...We present a detailed analysis of near zero-energy Feshbach resonances in ultracold collisions of atom and molecule,taking the He–PH system as an example, subject to superimposed electric and magnetic static fields. We find that the electric field can induce Feshbach resonance which cannot occur when only a magnetic field is applied, through couplings of the adjacent rotational states of different parities. We show that the electric field can shift the position of the magnetic Feshbach resonance, and change the amplitude of resonance significantly. Finally, we demonstrate that, for narrow magnetic Feshbach resonance as in most cases of ultracold atom–molecule collision, the electric field may be used to modulate the resonance, because the width of resonance in electric field scale is relatively larger than that in magnetic field scale.展开更多
The effect of collision energy on the magnetically tuned^(6)Li-^(6)Li Feshbach resonance(FR)is investigated theoretically by using the coupled-channel(CC)method for the collision energy ranging from 1μK·kBto 100...The effect of collision energy on the magnetically tuned^(6)Li-^(6)Li Feshbach resonance(FR)is investigated theoretically by using the coupled-channel(CC)method for the collision energy ranging from 1μK·kBto 100μK·kB.At the collision energy of 1μK·kB,the resonance positions calculated are 543.152 Gs(s wave,the unit 1 Gs=10^(-4)T),185.109 Gs(p wave|ml|=0),and 185.113 Gs(p wave|ml|=1),respectively.The p-wave FR near 185 Gs exibits a doublet structure of 4 mGs,associated with dipole-dipole interaction.With the increase of the collision energy,it is found that the splitting width remains the same(4 mGs),and that the resonance positions of s and p waves are shifted to higher magnetic fields with the increase of collision energy.The variations of the other quantities including the resonance width and the amplitude of the total scattering section are also discussed in detail.The thermally averaged elastic rate coefficients at T=10,15,20,25 K are calculated and compared.展开更多
We review our recent theoretical advances in the dynamics of Bose Einstein condensates with tunable interactions using Feshbach resonance and external potential. A set of analytic and numerical methods for Gross Pitae...We review our recent theoretical advances in the dynamics of Bose Einstein condensates with tunable interactions using Feshbach resonance and external potential. A set of analytic and numerical methods for Gross Pitaevskii equations are developed to study the nonlinear dynamics of BoseEinstein condensates. Analytically, we present the integrable conditions for the Gross Pitaevskii equations with tunable interactions and external potential, and obtain a family of exact analytical solutions for one- and two-component Bose Einstein condensates in one and two-dimensional cases. Then we apply these models to investigate the dynamics of solitons and collisions between two solitons. Numerically, the stability of the analytic exact solutions are checked and the phenomena, such as the dynamics and modulation of the ring dark soliton and vector-soliton, soliton conversion via Feshbach resonance, quantized soliton and vortex in quasi-two-dimensional are also investigated. Both the exact and numerical solutions show that the dynamics of Bose Einstein condensates can be effectively controlled by the Feshbach resonance and external potential, which offer a good opportunity for manipulation of atomic matter waves and nonlinear excitations in Bose Einstein condensates.展开更多
Chemical reactions at ultracold temperatures have attracted great interest in recent years. The atom-exchange reaction between an atom and a weakly bound Feshbach molecule near overlapping Feshbach resonances presents...Chemical reactions at ultracold temperatures have attracted great interest in recent years. The atom-exchange reaction between an atom and a weakly bound Feshbach molecule near overlapping Feshbach resonances presents a simple and ideal example of the controlled ultracold chemistry. The energy released in the reaction can be tuned to be very small and thus the reaction products can be trapped and detected, allowing the study of state-to-state reaction dynamics. The reaction can be tuned from the exothermic regime to the endothermic regime, which allows to study the threshold behavior of an endothermic reaction. In this paper, we review the recent progress in studying the atom-exchange reaction involving Feshbach molecules in ultracold atomic gases.展开更多
Feshbach resonance is a resonance for two-atom scattering with two or more channels,in which a bound state is achieved in one channel.We show that this resonance phenomenon not only exists during the collisions of mas...Feshbach resonance is a resonance for two-atom scattering with two or more channels,in which a bound state is achieved in one channel.We show that this resonance phenomenon not only exists during the collisions of massive particles,but also emerges during the coherent transport of massless particles,that is,photons confined in the coupled resonator arrays linked by a separated cavity or a tunable two level system(TLS).When the TLS is coupled to one array to form a bound state in this setup,the vanishing transmission appears to display the photonic Feshbach resonance.This process can be realized through various experimentally feasible solid state systems,such as the couple defected cavities in photonic crystals and the superconducting qubit coupled to the transmission line.The numerical simulation based on the finite-different time-domain(FDTD) method confirms our assumption about the physical implementation.展开更多
基金funded by the National Key Research and Development Program of China(Grant No.2022YFA1404201)the National Natural Science Foundation of China(Grant Nos.62020106014,92165106,62175140,12074234,and 11974331)the Applied Basic Research Project of Shanxi Province,China(Grant No.202203021224001)。
文摘Interactions between atoms in ultracold quantum gases play an important role in the study of the quantum simulation of many-body physics.Feshbach resonance is a versatile tool to control atomic interactions,where the atom-loss spectra are widely used to characterize Feshbach resonances of various atomic species.Here,we report the experimental observation of momentum-induced broadening of widths in atom-loss spectra of narrow ^(133)Cs Feshbach resonances.We drive Bragg excitation to kick the Bose-Einstein condensate of Cs atoms in a cigar-shaped optical trap,and measure the atom-loss spectra of narrow Feshbach resonances of moving ultracold atoms near the magnetic fields 19.84 G and 47.97 G.We show that the widths of the atom-loss spectra are broadened for the atoms with the momenta of 2hk,and 4hk,and even observe splitting in the Feshbach resonance of the atoms with momentum 4hk.Our work may open the way for exploring the interesting physical phenomena arising from the collective velocity of colliding atoms that have been ignored in general.
基金supported by the National Natural Science Foundation for Distinguished Young Scholars of China (Grant No. 10725416)the National Basic Research Program of China (Grant No. 2006CB921101)the National Natural Science Foundation of China for Excellent Research Team, China (Grant No. 60821004)
文摘We report the experimental preparations of the absolute ground states of 87Rb and 40K atoms （｜F = 1, mF = 1 ） ＋ ｜F = 9/2, rnF ： -9/2）） by means of the radio-frequency and microwave adiabatic rapid passages, and the observation of magnetic Feshbach resonances in an ultracold mixture of bosonic STRb and fermionic 40K atoms between 0 T and 6.0 × 10^-2 T, including 7 homonuclear and 4 heteronuclear Feshbach resonances. The resonances are identified by the abrupt trap loss of atoms induced by the strong inelastic three-body collisions. These Feshbach resonances should enable the experimental control of interspecies interactions.
基金Project supported by the National Key Research and Development Program of China(Grant No.2018YFA0306502)the National Natural Science Foundation of China(Grant Nos.11521063 and 11904355)the Fund from the Chinese Academy of Sciences(CAS).
文摘We present an intensive study of the coupling between different Feshbach states and the hyperfine levels of the excited states in the adiabatic creation of^(23)Na^(40)K ground-state molecules.We use coupled-channel method to calculate the wave function of the Feshbach molecules,and give the short-range wave function of triplet component.The energies of the hyperfine excited states and the coupling strength between the Feshbach states and the hyperfine excited states are calculated.Our results can be used to prepare a specific hyperfine level of the rovibrational ground state to study the ultracold collisions involving molecules.
基金Project supported by the NSF of China (Grant No 10674113)the Program for NCET in University (Grant No NCET-06-0707)+1 种基金the Foundation for the Author of National Excellent Doctoral Dissertation of China (Grant No 200726)the NSF of Hunan Province,China (Grant No 06JJ50006)
文摘By using Darboux transformation, this paper studies analytically the nonlinear dynamics of a one-dimensional growing Bose-Einstein condensate （BEC）. It is shown that the growing model has an important effect on the amplitude of the soliton in the condensates. In the absence of the growing model, there exhibits the stable alternate bright solitons in the condensates. In the presence of the growing model, the obtained results show that the amplitude of the bright soliton decreases （increases） for the BEC growing coefficient Ω 〈 0 （Ω 〉 0）. Furthermore, we propose experimental protocols to manipulate the amplitude of the bright soliton by varying the scattering length via the Feshbach resonance in the future experiment.
基金supported by the National Natural Science Foundation of China(Grant Nos.10974024 and 11274056)
文摘We investigate the two-color laser modulation of the magnetically induced Feshbach resonance. The two-color laser is nearly resonant with an optical bound-to-bound transition at the resonance position. The analytical formula of scattering length is obtained by solving the Heisenberg equation. The scattering length can be modified by changing the Rabi frequencies or optical field frequency. By choosing the suitable optical parameters, the two-body loss coefficient K2 can be greatly reduced compared to the usual single optical scheme.
基金supported by the National Natural Science Foundation of China(Grant Nos.10874001 and 11374014)
文摘We present a detailed analysis of near zero-energy Feshbach resonances in ultracold collisions of atom and molecule,taking the He–PH system as an example, subject to superimposed electric and magnetic static fields. We find that the electric field can induce Feshbach resonance which cannot occur when only a magnetic field is applied, through couplings of the adjacent rotational states of different parities. We show that the electric field can shift the position of the magnetic Feshbach resonance, and change the amplitude of resonance significantly. Finally, we demonstrate that, for narrow magnetic Feshbach resonance as in most cases of ultracold atom–molecule collision, the electric field may be used to modulate the resonance, because the width of resonance in electric field scale is relatively larger than that in magnetic field scale.
基金supported by the National Key Research and Development Program of China(Grant No.2018YFA0306503)the National Natural Science Foundation of China(Grant Nos.21873016 and 12174044)+1 种基金the International Cooperation Fund Project of DBJI(Grant No.ICR2105)the Fundamental Research Funds for the Central Universities(Grant No.DUT21LK08)。
文摘The effect of collision energy on the magnetically tuned^(6)Li-^(6)Li Feshbach resonance(FR)is investigated theoretically by using the coupled-channel(CC)method for the collision energy ranging from 1μK·kBto 100μK·kB.At the collision energy of 1μK·kB,the resonance positions calculated are 543.152 Gs(s wave,the unit 1 Gs=10^(-4)T),185.109 Gs(p wave|ml|=0),and 185.113 Gs(p wave|ml|=1),respectively.The p-wave FR near 185 Gs exibits a doublet structure of 4 mGs,associated with dipole-dipole interaction.With the increase of the collision energy,it is found that the splitting width remains the same(4 mGs),and that the resonance positions of s and p waves are shifted to higher magnetic fields with the increase of collision energy.The variations of the other quantities including the resonance width and the amplitude of the total scattering section are also discussed in detail.The thermally averaged elastic rate coefficients at T=10,15,20,25 K are calculated and compared.
基金Acknowledgements We would like to express our sincere thanks to Z. X. Liangang L. Wu for their original works and figures. This work was supported by the NatiorLM Natural Science Foundation of China （Grant Nos. 10874235, 10934010, and 60978019）, the National Key Basic Research Special Foundation of China （Grant Nos. 2009CB930701, 2010CB922904, and 2011CB921500）.
文摘We review our recent theoretical advances in the dynamics of Bose Einstein condensates with tunable interactions using Feshbach resonance and external potential. A set of analytic and numerical methods for Gross Pitaevskii equations are developed to study the nonlinear dynamics of BoseEinstein condensates. Analytically, we present the integrable conditions for the Gross Pitaevskii equations with tunable interactions and external potential, and obtain a family of exact analytical solutions for one- and two-component Bose Einstein condensates in one and two-dimensional cases. Then we apply these models to investigate the dynamics of solitons and collisions between two solitons. Numerically, the stability of the analytic exact solutions are checked and the phenomena, such as the dynamics and modulation of the ring dark soliton and vector-soliton, soliton conversion via Feshbach resonance, quantized soliton and vortex in quasi-two-dimensional are also investigated. Both the exact and numerical solutions show that the dynamics of Bose Einstein condensates can be effectively controlled by the Feshbach resonance and external potential, which offer a good opportunity for manipulation of atomic matter waves and nonlinear excitations in Bose Einstein condensates.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0306502)the National Natural Science Foundation of China(Grant No.11521063)。
文摘Chemical reactions at ultracold temperatures have attracted great interest in recent years. The atom-exchange reaction between an atom and a weakly bound Feshbach molecule near overlapping Feshbach resonances presents a simple and ideal example of the controlled ultracold chemistry. The energy released in the reaction can be tuned to be very small and thus the reaction products can be trapped and detected, allowing the study of state-to-state reaction dynamics. The reaction can be tuned from the exothermic regime to the endothermic regime, which allows to study the threshold behavior of an endothermic reaction. In this paper, we review the recent progress in studying the atom-exchange reaction involving Feshbach molecules in ultracold atomic gases.
基金supported by the National Natural Science Foundation of China (Grant Nos.10474104,60433050 and10704023)the National Basic Research Program of China (Grant Nos.2006CB921205 and 2005CB724508)
文摘Feshbach resonance is a resonance for two-atom scattering with two or more channels,in which a bound state is achieved in one channel.We show that this resonance phenomenon not only exists during the collisions of massive particles,but also emerges during the coherent transport of massless particles,that is,photons confined in the coupled resonator arrays linked by a separated cavity or a tunable two level system(TLS).When the TLS is coupled to one array to form a bound state in this setup,the vanishing transmission appears to display the photonic Feshbach resonance.This process can be realized through various experimentally feasible solid state systems,such as the couple defected cavities in photonic crystals and the superconducting qubit coupled to the transmission line.The numerical simulation based on the finite-different time-domain(FDTD) method confirms our assumption about the physical implementation.
