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Dependence of Rydberg-atom-based sensor performance on different Rydberg atom populations in one atomic-vapor cell
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作者 武博 姚佳伟 +2 位作者 吴逢川 安强 付云起 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期365-370,共6页
The atomic-vapor cell is a vital component for Rydberg atomic microwave sensors,and impacts on overall capability of Rydberg sensors.However,the conventional analysis approach on effect of vapor-cell length contains t... The atomic-vapor cell is a vital component for Rydberg atomic microwave sensors,and impacts on overall capability of Rydberg sensors.However,the conventional analysis approach on effect of vapor-cell length contains two implicit assumptions,that is,the same atomic population density and buffer gas pressure,which make it unable to accurately capture actual response about effect of Rydberg-atom-based sensor performance on different Rydberg atom populations.Here,utilizing a stepped cesium atomic-vapor cell with five different dimensions at the same atomic population density and buffer gas pressure,the height and full width at half maximum of electromagnetically induced transparency(EIT)signal,and the sensitivity of the atomic superheterodyne sensor are comprehensively investigated under conditions of the same Rabi frequencies(saturated laser power).It is identified that EIT signal height is proportional to the cell length,full width at half maximum and sensitivity grow with the increment of cell length to a certain extent.Employing the coherent integration signal theory and atomic linear expansion coefficient method,theoretical analysis of the EIT height and sensitivity are further investigated.The results could shed new light on understanding and design of ultrahigh-sensitivity Rydberg atomic microwave sensors and find promising applications in quantum measurement,communication,and imaging. 展开更多
关键词 Rydberg atom population Rydberg-atom-based receiver stepped atomic-vapor cell
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Measurements of Majorana transition frequency shift in caesium atomic fountain clocks
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作者 施俊如 王心亮 +6 位作者 杨帆 白杨 管勇 范思晨 刘丹丹 阮军 张首刚 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第4期42-49,共8页
The caesium atomic fountain clock is a primary frequency standard.During its operation,a Majorana transition frequency shift will occur once a magnetic field at some special locations along the atomic trajectory is si... The caesium atomic fountain clock is a primary frequency standard.During its operation,a Majorana transition frequency shift will occur once a magnetic field at some special locations along the atomic trajectory is singular.In this study,by developing a physical model,we analyzed the magnetic field requirements for atomic adiabatic transition and calculated the influence of the Majorana atomic transition on the atomic state via a quantum method.Based on the simulation results for the magnetic field in the fountain clock,we applied the Monte Carlo method to simulate the relationship between the Majorana transition frequency shift and the magnetic field at the entrance of the magnetic shielding,as well as the initial atomic population.Measurement of the Majorana transition frequency shift was realized by state-selecting asymmetrically populated atoms.The relationship between the Majorana transition frequency shift and the axial magnetic field at the entrance of the magnetic shielding was obtained.The measured results were essentially consistent with the calculated results.Thus,the magnetic field at the entrance of the magnetic shielding was configured,and the Majorana transition frequency shift of the fountain clock was calculated to be 4.57×10^(-18). 展开更多
关键词 caesium atomic fountain clock Majorana transition frequency shift magnetic field initial atomic population
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Stable ^(85)Rb micro vapour cells:fabrication based on anodic bonding and application in chip-scale atomic clocks 被引量:3
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作者 苏娟 邓科 +4 位作者 郭等柱 汪中 陈兢 张耿民 陈徐宗 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第11期243-250,共8页
We describe the microfabrication of ^85Rb vapour cells using a glass-silicon anodic bonding technique and in situ chemical reaction between rubidium chloride and barium azide to produce Rb. Under controlled conditions... We describe the microfabrication of ^85Rb vapour cells using a glass-silicon anodic bonding technique and in situ chemical reaction between rubidium chloride and barium azide to produce Rb. Under controlled conditions, the pure metallic Rb drops and buffer gases were obtained in the cells with a few mm^3 internal volumes during the cell sealing process. At an ambient temperature of 90 ℃ the optical absorption resonance of ^85Rb D1 transition with proper broadening and the corresponding coherent population trapping (CPT) resonance, with a signal contrast of 1.5% and linewidth of about 1.7 kHz, have been detected. The sealing quality and the stability of the cells have also been demonstrated experimentally by using the helium leaking detection and the after-9-month optoelectronics measurement which shows a similar CPT signal as its original status. In addition, the physics package of chip-scale atomic clock (CSAC) based on the cell was realized. The measured frequency stability of the physics package can reach to 2.1 × 10^-10 at one second when the cell was heated to 100 ℃ which proved that the cell has the quality to be used in portable and battery-operated devices. 展开更多
关键词 ^85Rb Micro vapour cell anodic bonding coherent population trapping chip-scale atomic clock frequency stability
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Coherent population trapping magnetometer by differential detecting magneto–optic rotation effect 被引量:2
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作者 张樊 田原 +1 位作者 张奕 顾思洪 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期355-358,共4页
A pocket coherent population trapping(CPT) atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting... A pocket coherent population trapping(CPT) atomic magnetometer scheme that uses a vertical cavity surface emitting laser as a light source is proposed and experimentally investigated.Using the differential detecting magneto–optic rotation effect,a CPT spectrum with the background canceled and a high signal-to-noise ratio is obtained.The experimental results reveal that the sensitivity of the proposed scheme can be improved by half an order,and the ability to detect weak magnetic fields is extended one-fold.Therefore,the proposed scheme is suited to realize a pocket-size CPT magnetometer. 展开更多
关键词 coherent population trapping atomic magnetometer magneto–optic rotation effect
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A first-principle calculation of structural,mechanical and electronic properties of titanium borides 被引量:3
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作者 闫海燕 魏群 +1 位作者 常少梅 郭平 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第7期1627-1633,共7页
The first-principle calculations are performed to investigate the structural,mechanical and electronic properties of titanium borides (Ti2B,TiB and TiB2).Those calculated lattice parameters are in good agreement wit... The first-principle calculations are performed to investigate the structural,mechanical and electronic properties of titanium borides (Ti2B,TiB and TiB2).Those calculated lattice parameters are in good agreement with the experimental data and previous theoretical values.All these borides are found to be mechanically stable at ambient pressure.Compared with parent metal Ti (120 GPa),the larger bulk modulus of these borides increase successively with the increase of the boron content in three borides,which may be due to direction bonding introduced by the boron atoms in the lattice and the strong covalent Ti-B bonds.Additionally,TiB can be regarded as a candidate of incompressible and hard material besides TiB2.Furthermore,the elastic anisotropy and Debye temperatures are also discussed by investigating the elastic constants and moduli.Electronic density of states and atomic Mulliken charges analysis show that chemical bonding in these titanium borides is a complex mixture of covalent,ionic,and metallic characters. 展开更多
关键词 titanium borides first-principle calculations mechanical properties density of states Mulliken atomic population analysis
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Atomic population distribution of excited states in He electrodeless discharge lamp
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作者 陶智明 王彦飞 +4 位作者 张盛楠 王东颖 洪叶龙 庄伟 陈景标 《Chinese Optics Letters》 SCIE EI CAS CSCD 2013年第10期11-14,共4页
Population ratios between excited states are measured to build the excited state Faraday anomalous dispersion optical filter(ESFADOF). We calculate these values between the excited states according to the spontaneous ... Population ratios between excited states are measured to build the excited state Faraday anomalous dispersion optical filter(ESFADOF). We calculate these values between the excited states according to the spontaneous transition probabilities using rate equations and the measured intensities of fluorescence spectral lines of He atoms in an electrodeless discharge lamp in the visible spectral region from 350 to 730 nm. The electrodeless discharge lamp with populations in excited states can be used to realize the frequency stabilization reference of the laser frequency standard. This lamp can also build ESFADOFs for submarine communication application in the blue-green wavelength to simplify the system without the use of a pump laser. 展开更多
关键词 RATE atomic population distribution of excited states in He electrodeless discharge lamp
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Spontaneous Emission Originating from Atomic BEC Interacting with a Single-Mode Quantized Field 被引量:1
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作者 E.Ghasemian M.K.Tavassoly 《Communications in Theoretical Physics》 SCIE CAS CSCD 2018年第6期711-721,共11页
In this paper we present a general theoretical model for the interaction between a number of two-level atoms constituting Bose-Einstein condensate (BEG) and a single-mode quantized field. In addition to the usual in... In this paper we present a general theoretical model for the interaction between a number of two-level atoms constituting Bose-Einstein condensate (BEG) and a single-mode quantized field. In addition to the usual interacting terms, we take into account interatom as well as higher-order atom-field interactions. To simplify the Hamiltonian of system, after using the Bogoliubov approximation we proceed to calculate the transformed operators of atoms and field. Then, to quantify the spontaneous emission, we get analytical expressions for the expectation value of Jz as the atomic population inversion (API), in the cases of number and coherent states for the atomic subsystem. Our results show that the above-mentioned model interaction leads to the appearance of collapse-revival phenomenon in API. In more detail, the revival time may be tuned by adjusting the interatom interaction constant. Also, the damping process lowers the amplitude of API, but does not change the CR times for weak damping. Moreover, increasing the damping may decrease the number of CRs in a given interval of time such that no revival occurs. Briefly, it may be concluded that in the resonant case the revival times are insensitive to the change of the higher-order atom-field interaction constant and are affected only by the interatom interactions. Finally, we express that, how we can find a practical procedure to measure the quantum states of atoms in BEG. 展开更多
关键词 Bose-Einstein condensate atom-field interaction spontaneous emission atomic population inversion collapse-revival phenomenon
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