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Degenerate cascade fluorescence: Optical spectral-line narrowing via a single microwave cavity

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Chinese Physics B 2021年第6期30卷 346-358页

作者： Liang Hu Xiang-Ming Hu Qing-Ping Hu College of Physical Science and Technology Central China Normal UniversityWuhan 430079China

For a three-level atom, two nondegenerate(even microwave and optical) electric dipole transitions are usually allowed;for either of these, the fluorescence spectra are well-described in terms of spontaneous transitions from a triplet of dressed sublevels to an adjacent lower-lying triplet. When the three dressed sublevels are equally spaced from each other, a remarkable feature known as degenerate cascade fluorescence takes place, which displays a five-peaked structure. We show that a single cavity can make all the spectral lines extremely narrow, whether they arise from cavity-coupled or cavity-free transitions. This effect is based on intrinsic cascade lasing feedback and makes it possible to use a single microwave cavity(even a bad cavity) to narrow the spectral lines in the optical frequency regime.

关键词： resonance fluorescence narrow spectral lines microwave cavity

Design and test of the microwave cavity in an optically-pumped Rubidium beam frequency standard

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Chinese Physics B 2015年第1期24卷 190-194页

作者：刘畅王延辉 School of Electronics engineering and Computer Science Peking University

We are developing a compact rubidium atomic beam frequency standard with optical pumping and detection. The cavity for microwave interrogation is an important part of the clock. The cavity in our design is a Ramsey-type, E-bend one, which is the same as the conventional method in most cesium beam clocks. Requirements for the design are proposed based on the frequency shift associated with the cavity. The basic structure of the cavity is given by theoretical analysis and detailed dimensions are determined by means of electromagnetic field simulation with the help of commercial *** cavity is manufactured and fabricated successfully. The preliminary test result of the cavity is given, which is in good agreement with the simulation. The resonant frequency is 6.835 GHz, equal to the clock transition frequency of87 Rb, and the loaded quality factor is 500. These values are adjustable with posts outside the cavity. Estimations on the Ramsey line width and several frequency shifts are made.

关键词： rubidium beam clock optical pumping microwave cavity frequency shift

Charge Qubit Storage and Its Engineered Decoherence via microwave cavity

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Communications in Theoretical Physics 2005年第2期43卷 213-218页

作者： GAOYi-Bo LIChong AppliedPhysicsDepartment BeijingUniversityofTechnologyBeijing100022China／／InstituteofTheoreticalPhysicstheChineseAcademyofSciencesBeijing100080China InstituteofTheoreticalPhysics theChineseAcademyofSciencesBeijing100080China

We study the entanglement of the superconducting charge qubit with the quantized electromagnetic field in a microwave cavity. It can be controlled dynamically by a classical external field threading the SQUID within the charge qubit. Utilizing the controllable quantum entanglement, we can demonstrate the dynamic process of the quantum storage of information carried by charge qubit. On the other hand, based on this engineered quantum entanglement, we can also demonstrate a progressive decoherence of charge cubit with quantum jump due to the coupling with the cavity field in quasi-classical state.

关键词： charge qubit engineered decoherence quantum information storage microwave cavity

Study of the cavity-magnon-polariton transmission line shape

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Science China(Physics,Mechanics & Astronomy) 2016年第11期59卷 70-80页

作者： Michael Harder LiHui Bai Christophe Match Jesko Sirker CanMing Hu Department of Physics and Astronomy University of Manitoba

We experimentally and theoretically investigate the microwave transmission line shape of the cavity-magnon-polariton(CMP)created by inserting a low damping magnetic insulator into a high quality 3D microwave cavity. While fixed field measurements are found to have the expected Lorentzian characteristic, at fixed frequencies the field swept line shape is in general asymmetric. Such fixed frequency measurements demonstrate that microwave transmission can be used to access magnetic characteristics of the CMP,such as the field line width H. By developing an effective oscillator model of the microwave transmission we show that these line shape features are general characteristics of harmonic coupling. At the same time, at the classical level the underlying physical mechanism of the CMP is electrodynamic phase correlation and a second model based on this principle also accurately reproduces the experimental line shape features. In order to understand the microscopic origin of the effective coupled oscillator model and to allow for future studies of CMP phenomena to extend into the quantum regime, we develop a third, microscopic description,based on a Green's function formalism. Using this method we calculate the transmission spectra and find good agreement with the experimental results.

关键词： cavity-magnon-polariton strong-coupling microwave cavity ferromagnetic resonance

A design of resonant cavity with an improved coupling-adjusting mechanism for the W-band EPR spectrometer

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Chinese Physics B 2022年第11期31卷 115-120页

作者： Yu He Runqi Kang Zhifu Shi Xing Rong Jiangfeng Du CAS Key Laboratory of Microscale Magnetic Resonance and School of Physical Sciences University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Chinainstru&Quantumtech(Hefei)Co. LtdHefei 230031China

We report a new design of resonant cavity for a W-band electron paramagnetic resonance(EPR)*** improved coupling-adjusting mechanism,which is robust,compact,and suits with both solenoid-type and split-pair magnets,is utilized on the cavity,and thus enables both continuous-wave(CW)and pulsed EPR *** is achieved by a tiny metal cylinder in the *** coupling coefficient can be varied from 0.2 to ***,two pistons at each end of the cavity allow for adjustment of the resonant frequency.A horizontal TE_(011) geometry also makes the cavity compatible with the two frequently used types of *** coupling-varying ability has been demonstrated by reflection coefficient(S_(11))*** and pulsed EPR experiments have been *** performance data indicates a prospect of wide applications of the cavity in fields of physics,chemistry and biology.

关键词： electron paramagnetic resonance W-band microwave cavity coupling coefficient

Physics package based on intracavity laser cooling ^(87)Rb atoms for space cold atom microwave clock

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Chinese Physics B 2024年第7期33卷 22-26页

作者：邓思敏达任伟项静峰赵剑波李琳张迪万金银孟艳玲蒋小军李唐刘亮吕德胜 Aerospace Laser Technology and System Department Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Mechanics Chinese Academy of SciencesShanghai 201800China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

This article proposes a new physics package to enhance the frequency stability of the space cold atom clock with the advantages of a microgravity environment. Clock working processes, including atom cooling, atomic state preparation,microwave interrogation, and transition probability detection, are integrated into the cylindrical microwave cavity to achieve a high-performance and compact physics package for the space cold atom clock. We present the detailed design and ground-test results of the cold atom clock physics package in this article, which demonstrates a frequency stability of 1.2×10^(-􀀀12) τ^(-1/2) with a Ramsey linewidth of 12.5 Hz, and a better performance is predicted with a 1 Hz or a narrower Ramsey linewidth in microgravity environment. The miniaturized cold atom clock based on intracavity cooling has great potential for achieving space high-precision time-frequency reference in the future.

关键词： atomic clock microgravity microwave cavity space station frequency stability

Design of a Miniaturized cavity for Space Hydrogen Masers

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Design of a Miniaturized Cavity for Space Hydrogen Masers