- 标题
- 摘要
- 关键词
- 实验方案
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Re-Evaluation of the Gravity Transfer Component of the NRC Kibble Balance
摘要： We describe a project to re-evaluate the transfer of the absolute determination of the local acceleration due to gravity from a nearby site, to the center of mass of the test mass in the NRC Kibble Balance. This re-evaluation includes the characterization of the sensitivity of a relative gravity meter to the fringing magnetic flux density, as well as the attenuation provided by a simple magnetic shield.
关键词： revised SI,Gravity measurement,watt balance,magnetic field,Planck constant,SI units
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Rabi Resonance Measurements Based on CS Vapor Cell for Microwave Magnetic Field Detection in Free Space
摘要： In this paper we characterized the lineshapes of Rabi resonances for microwave (MW) magnetic field with cesium vapor cell in free space. The relation between resonance lineshapes and phase modulation frequency under different experimental parameters are investigated. Based on the obtained lineshapes, the evaluation of Rabi frequency has been done in free space. Optimal laser intensity and cell temperature are obtained in our experiment, preliminary analysis of the experimental results is reported.
关键词： Atom-based microwave measurements,lineshapes,atomic vapor cell,free space,magnetic field,Rabi resonance
更新于2025-09-10 09:29:36
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris, France (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - High-Precision Magnetic Field Vector Measurement Based on the Quantum Coherent Superposition States
摘要： The high precision measurement of magnetic field vector based on quantum coherent superposition states due to the interaction of the atomic system with linearly polarized light and magnetic field is described. The coordinate systems are physically orthogonal, which defined by the directions of light polarization and propagation. Because the quantum beat signals resulted by the coherent superposition states are no longer affected by nonlinear Zeeman shift, the measurement has smaller systematic error. The method is suitable for the measurements of vector fields such as the Earth’s magnetic field.
关键词： magnetic field vector,Atomic magnetometer,quantum coherent superposition state,precision measurement,quantum beat technology
更新于2025-09-10 09:29:36
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Simulation of microchannel plate photomultiplier tube in high magnetic fields
摘要： The microchannel plate photomultiplier tube (MCP-PMT) used in high energy physics experiments usually needs to be able to operate in strong magnetic fields. In this paper, a 3D MCP-PMT model is developed in CST studio suite to study the magnetic field up to 5 T effect on the photoelectrons traveling from the photocathode to the MCP. Results predict that a growing number of photoelectrons strike back to the photocathode with enhancing magnetic field, which not only decreases electron collection efficiency and gain, but also impairs the photocathode lifetime.
关键词： Magnetic field,MCP-PMT,Collection efficiency,Microchannel plate
更新于2025-09-09 09:28:46
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Precision Measurement of Magnetic Field Based on Second-Order Sideband Generation in a Hybrid Electromagnetic-Optomechanical System
摘要： Realizing the precise measurement of the magnetic field is of great significance in many fields, including optics, metrology, bioscience, and engineering technology. With the development of nanophotonics, optomechanical systems have provided an on-chip platform to explore new availability for high-sensitivity measurement due to its extreme sensitivity on weak force [Ref. Nat. Nanotechnol. 7, 509 (2012)]. In this paper, a theoretical scheme for precision measurement of magnetic field based on a nonlinear optomechanical effect: second-order sideband generation in a hybrid electromagnetic-optomechanical system is proposed. We find that the system exhibits a kenspeckle magnetic-field-dependent generation of the frequency component at the second-order sideband, which is more sensitive than the previous paper based on optomechanically induced transparency. Numerical calculations show that the measurement accuracy of the magnetic field in our scheme may reach the order of nT or even smaller, so our findings will provide a more accurate solution for the precise measurement of magnetic fields.
关键词： second-order sideband generation,Precise measurement,cavity optomechanics,magnetic field
更新于2025-09-09 09:28:46
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Quantum Hall stripes in high-density GaAs/AlGaAs quantum wells
摘要： We report on quantum Hall stripes (QHSs) formed in higher Landau levels of GaAs/AlGaAs quantum wells with high carrier density (ne > 4 × 1011 cm?2) which is expected to favor QHS orientation along the unconventional (cid:2)1ˉ10(cid:3) crystal axis and along the in-plane magnetic ?eld B(cid:4). Surprisingly, we ?nd that at B(cid:4) = 0 QHSs in our samples are aligned along the (cid:2)110(cid:3) direction and can be reoriented only perpendicular to B(cid:4). These ?ndings suggest that high density alone is not a decisive factor for either abnormal native QHS orientation or alignment with respect to B(cid:4), while quantum con?nement of the 2DEG likely plays an important role.
关键词： quantum confinement,high carrier density,in-plane magnetic field,quantum Hall stripes,GaAs/AlGaAs quantum wells
更新于2025-09-09 09:28:46
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Magnetic Optical FBG Sensors Using Optical Frequency-Domain Reflectometry
摘要： The optical frequency-domain reflectometry (OFDR) sensing system and signal processing method, which is based on the short-time Fourier transform, enable us to interrogate reflected wavelengths of fiber Bragg gratings (FBGs) and their relative position along the optical fiber with high spatial resolution. An FBG is an optical fiber with an appropriately inscribed periodic refractive index modulation. When a broadband optical signal is launched into the FBG, narrow wavelength bandwidth is reflected. Due to an attached transducer, such as Terfenol-D, the reflected wavelength changes with the applied magnetic field. The proposed magnetic FBG sensor consists of a small rod of magnetostrictive alloy TbDyFe, also known as Terfenol-D, which has large magnetostriction. The FBG is attached to the Terfenol-D rod with UV glue. Consequently, the external magnetic field is applied to the sensor and as a result, the Terfenol-D rod length increases. The reflected wavelength shift is observed and measured by the OFDR sensing system. Therefore, we determine the external magnetic field along the optical fiber from the reflected Bragg wavelength shift. The measurement results show that the proposed magnetic field sensors based on Terfenol-D using OFDR can be successfully used for measurement of the external magnetic field along an optical fiber.
关键词： Terfenol-D,optical frequency-domain reflectometry (OFDR),magnetic field sensor,Fiber Bragg gratings (FBGs)
更新于2025-09-09 09:28:46
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Re-amorphization of GeSbTe alloys not through a melt-quenching process
摘要： Ge–Sb–Te (GST) alloys are one of the most successful chalcogenides used in rewritable optical discs and electric non-volatile memories. In these materials the structural phase transition between amorphous and crystalline states is used for recording. Here, we report that a melt-quenching method is not necessarily the only way to form a high-resistance phase. We found that amorphous-like grains with high resistance are formed in the GST crystal film by holding it at above the crystallization temperature under an external magnetic field, followed by cooling accompanied with pulse current injection. The treatment may open new route for ultra-low current switching phase change memory.
关键词： pulse current injection,Ge–Sb–Te alloys,phase change memory,re-amorphization,magnetic field
更新于2025-09-09 09:28:46
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PLD fabrication of oriented nanowires in magnetic field
摘要： This paper presents an experimental investigation on laser-assisted fabrication of oriented nanowires composed by magnetic nanoparticles. The nanowires were produced by implementation of pulsed laser deposition in presence of a magnetic field. The application of an external magnetic field led to the formation of nanowires with a length of several micrometers whose orientation is influenced by the direction of the magnetic field lines. The influence of the type of ambient gas and its pressure on morphology and phase composition of the deposited samples was investigated. It was found that the ambient gas has direct influence on both the degree of orientation and the phase composition of the nanowires. SEM analysis of samples deposited at different target-substrate distances showed that the density of the nanowires decreases with the increase of the distance. A preliminary result on the magnetic properties of the produced nanowires is also reported.
关键词： Magnetic field,Iron oxide,Nanowires,PLD
更新于2025-09-09 09:28:46
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A novel use of etched multi-mode fibre as magnetic field sensor
摘要： In this study, an optical fibre magnetic field sensor is experimentally demonstrated using chemical etched multimode fibre sandwiched between two single mode fibres. The obtained result of the magnetic field and refractive index response shows that the decreasing fibre diameter in the sensing region plays an important role to enhance the sensitivity of the device. The magnetic field sensing is based on a tunable refractive index (RI) property of magnetic fluid infiltrated into the capillary tube. The sensing system is verified by testing RI of different concentrations of sodium chloride (NaCl) solution before sealing in capillary tube. Experimental results show that the sensor with taper fibre diameter of 45?μm has relatively high magnetic field sensitivity of ～ 0.993?dB/mT ranging from 0 to 6?mT. The proposed devices find potential applications in magnetic field sensing.
关键词： optical fibre magnetic field sensor,sensitivity,chemical etched multimode fibre,refractive index,magnetic fluid
更新于2025-09-04 15:30:14