We propose constructing a quantum interference configuration for cold atoms in a magneto-optical trap by applying a radio frequency field, which coherently couples adjacent Zeeman sublevels, in combination with a repu...We propose constructing a quantum interference configuration for cold atoms in a magneto-optical trap by applying a radio frequency field, which coherently couples adjacent Zeeman sublevels, in combination with a repumping laser field. One effect of this interference is that a dip exists in the absorption of the repumping light when the radio frequency is scanned. Our prediction has been indirectly detected through the fluorescence of cold atoms in a preliminary experiment.展开更多
We numerically simulate the dynamical behavior of BEC in one-dimensional incommensurable optical lattice by split-step Fourier method in a time-dependent one-dimensional Gross Pitaevskii equation. It is indicated that...We numerically simulate the dynamical behavior of BEC in one-dimensional incommensurable optical lattice by split-step Fourier method in a time-dependent one-dimensional Gross Pitaevskii equation. It is indicated that the atom-atom interaction will weaken the localization and broaden the wave function, and it will destroy the adiabaticity of the ramped loading process in both single lattice and incommensurate lattice due to the broadening effect. A band structure model can interpret the difference of the adiabatic condition with non-interacting BEC in these optical lattices.展开更多
We employ a sample of cold 87Rb atoms in a magneto-optical trap to study the impulse responses and spatial characters of backward conjugate waves in a four-wave mixing process. We measure the slow and superluminal gro...We employ a sample of cold 87Rb atoms in a magneto-optical trap to study the impulse responses and spatial characters of backward conjugate waves in a four-wave mixing process. We measure the slow and superluminal group velocities of backward conjugate waves, and find the sensitive variation of the spatial mode of backward waves with the probe-pump detuning and the dependence of the reflectance on the magnetic field, while the trapping magnetic field exists.展开更多
We propose a scheme to implement single-qubit operations for singlet-triplet qubits located in an isolated double-well potential with fixed inter-site tunneling when superexchange interactions predominate. Arbitrary s...We propose a scheme to implement single-qubit operations for singlet-triplet qubits located in an isolated double-well potential with fixed inter-site tunneling when superexchange interactions predominate. Arbitrary single-qubit gates can be realized by a sequence composed of two elementary operations which can be switched between different parameter regimes by adjusting slightly the relative energy bias of trapped atoms in each sub-well site. The experimental feasibility of the strategy and the fidelity of basic rotation operations are also analyzed.展开更多
We propose a scheme to produce a uniform magnetic field with a system comprising a pair of coils and an atom chip. After optimizing the parameters of the chip wires, we improve the homogeneity of the magnetic field by...We propose a scheme to produce a uniform magnetic field with a system comprising a pair of coils and an atom chip. After optimizing the parameters of the chip wires, we improve the homogeneity of the magnetic field by two orders of magnitude. We exhibit that this method can be applied in the investigation of Efimov physics in 87Rb-40K mixture.展开更多
We demonstrate continuous imaging of a single 87Rb atom confined in a steep magneto-optical trap with an electron-multiplying charge-coupled device （EMCCD） camera and realize a one-dimensional micro-optical trap arr...We demonstrate continuous imaging of a single 87Rb atom confined in a steep magneto-optical trap with an electron-multiplying charge-coupled device （EMCCD） camera and realize a one-dimensional micro-optical trap array with a Dammann grating. We adopt several methods to reduce the noise in the fluorescence signal we obtain with the EMCCD. Step jumping characteristics of the fluorescence demonstrate capturing and losing of individual atoms.展开更多
We model a one-dimensional Bose–Einstein condensate with the one-dimensional Gross–Pitaevskii equation(1 D GPE) incorporating higher-order interaction effects. Based on the F-expansion method, we analytically solve ...We model a one-dimensional Bose–Einstein condensate with the one-dimensional Gross–Pitaevskii equation(1 D GPE) incorporating higher-order interaction effects. Based on the F-expansion method, we analytically solve the1 D GPE, identifying the typical soliton solution under certain experimental settings within the general wave-like solution set, and demonstrating the applicability of the theoretical treatment that is employed.展开更多
Non-classical paired photons are generated by a four-wave mixing process in a far-detuning three-level system with cold atoms.A violation of the Cauchy–Schwartz inequality of a factor of 310 is observed.This phenomen...Non-classical paired photons are generated by a four-wave mixing process in a far-detuning three-level system with cold atoms.A violation of the Cauchy–Schwartz inequality of a factor of 310 is observed.This phenomenon shows that paired photons have a non-classical correlation.The experimental results are compared with theoretical results obtained using perturbation theory.The oscillation frequencies of the two-photon intensity correlation functions are in reasonable agreement with the effective Rabi frequencies of the coupling laser.However,we find that the dephasing rates(or decay rates)observed are far larger than the theoretical values.展开更多
基金Supported by the Ministry of Science and Technology of China under Grant No.95-Yu-34the National Natural Science Foundation of China under Grant No.19834046in part by the Chinese Postdoctoral Science Foundation and Shanghai Natural Science Foundation.
文摘We propose constructing a quantum interference configuration for cold atoms in a magneto-optical trap by applying a radio frequency field, which coherently couples adjacent Zeeman sublevels, in combination with a repumping laser field. One effect of this interference is that a dip exists in the absorption of the repumping light when the radio frequency is scanned. Our prediction has been indirectly detected through the fluorescence of cold atoms in a preliminary experiment.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10334050 and 10804115, the National Basic Research Program of China under Grant No 2006CB921202, and the Knowledge Innovation Project of Chinese Academy of Sciences.
文摘We numerically simulate the dynamical behavior of BEC in one-dimensional incommensurable optical lattice by split-step Fourier method in a time-dependent one-dimensional Gross Pitaevskii equation. It is indicated that the atom-atom interaction will weaken the localization and broaden the wave function, and it will destroy the adiabaticity of the ramped loading process in both single lattice and incommensurate lattice due to the broadening effect. A band structure model can interpret the difference of the adiabatic condition with non-interacting BEC in these optical lattices.
基金Supported by the National Fundamental Research Program of China under Grant No 2006CB921202, the National Natural Science Foundation of China under Grant No 10804115, and the Knowledge Innovation Project of Chinese Academy of Sciences.
文摘We employ a sample of cold 87Rb atoms in a magneto-optical trap to study the impulse responses and spatial characters of backward conjugate waves in a four-wave mixing process. We measure the slow and superluminal group velocities of backward conjugate waves, and find the sensitive variation of the spatial mode of backward waves with the probe-pump detuning and the dependence of the reflectance on the magnetic field, while the trapping magnetic field exists.
基金Supported by the National Basic Research Program of China under Grant No 2006CB921202, the National Natural Science Foundation of China under Grant No 10804115, and the Knowledge Innovation Project of Chinese Academy of Sciences. J.Q. also acknowledges the support by the Shanghai Postdoctoral Scientific Program.
文摘We propose a scheme to implement single-qubit operations for singlet-triplet qubits located in an isolated double-well potential with fixed inter-site tunneling when superexchange interactions predominate. Arbitrary single-qubit gates can be realized by a sequence composed of two elementary operations which can be switched between different parameter regimes by adjusting slightly the relative energy bias of trapped atoms in each sub-well site. The experimental feasibility of the strategy and the fidelity of basic rotation operations are also analyzed.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674338,11791240178,and 11547024)Innovation Training Programs for Undergraduates,Chinese Academy of Sciences(Grant No.KCJH-80140-2016-018)
文摘We propose a scheme to produce a uniform magnetic field with a system comprising a pair of coils and an atom chip. After optimizing the parameters of the chip wires, we improve the homogeneity of the magnetic field by two orders of magnitude. We exhibit that this method can be applied in the investigation of Efimov physics in 87Rb-40K mixture.
基金Supported by the National Natural Science Foundation of China under Grant No 10804115, the National Basic Research Program of China under Grant No 2006CB921202, and the Knowledge Innovation Project of Chinese Academy of Sciences.
文摘We demonstrate continuous imaging of a single 87Rb atom confined in a steep magneto-optical trap with an electron-multiplying charge-coupled device （EMCCD） camera and realize a one-dimensional micro-optical trap array with a Dammann grating. We adopt several methods to reduce the noise in the fluorescence signal we obtain with the EMCCD. Step jumping characteristics of the fluorescence demonstrate capturing and losing of individual atoms.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11791240178,11674338,and 11547024
文摘We model a one-dimensional Bose–Einstein condensate with the one-dimensional Gross–Pitaevskii equation(1 D GPE) incorporating higher-order interaction effects. Based on the F-expansion method, we analytically solve the1 D GPE, identifying the typical soliton solution under certain experimental settings within the general wave-like solution set, and demonstrating the applicability of the theoretical treatment that is employed.
基金by the National Natural Science Foundation of China under Grant No 10804115the National Basic Research Program of China under Grant Nos 2006CB921202 and 2011CB921504+1 种基金the Knowledge Innovation Project of Chinese Academy of Sciencesthe Shanghai Committee of Science and Technology under Grant No 09DJ1400700.
文摘Non-classical paired photons are generated by a four-wave mixing process in a far-detuning three-level system with cold atoms.A violation of the Cauchy–Schwartz inequality of a factor of 310 is observed.This phenomenon shows that paired photons have a non-classical correlation.The experimental results are compared with theoretical results obtained using perturbation theory.The oscillation frequencies of the two-photon intensity correlation functions are in reasonable agreement with the effective Rabi frequencies of the coupling laser.However,we find that the dephasing rates(or decay rates)observed are far larger than the theoretical values.
