A Design of Cesium Atomic Magnetometer Based on Circular Dichroism

2012 ◽  
Vol 203 ◽  
pp. 268-272 ◽  
Author(s):  
Xian Jin Zeng ◽  
Mo Si Hao ◽  
Qing Meng Li ◽  
Qiang Liu ◽  
Jun Hai Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Circular Dichroism ◽  
Spin Exchange ◽  
Laser Light ◽  
Tracking System ◽  
Frequency Tracking ◽  
Highly Sensitive ◽  
Optical Configuration ◽  
Circular Dichroïsm ◽  
The Magnetic Field

Recently, atomic magnetometers have been reported as the most sensitive magnetometers by completely eliminating the spin exchange relaxation. In this paper, we described a design of highly sensitive cesium atomic magnetometer based on circular dichroism, which had the advantage of easily locking the probing laser to the necessary frequency compared with those based on circular birefringence. In order to polarize the cesium atoms uniformly, the pumping laser light was separated into two counter-propagating and counter-circular polarization beams through the atomic vapor cell. We employed a circular analyzer optical configuration to measure the ellipticity of the probing light, which indicated the amplitude of the magnetic field. The external magnetic field was tracked by a digital auto frequency tracking system.

OPTICAL PROPERTIES OF CUPRATE SUPERCONDUCTORS INFLUENCED BY A MAGNETIC FIELD

1991 ◽  
Vol 05 (10) ◽  
pp. 1539-1549 ◽  
Author(s):  
H. J. WEBER
Keyword(s):  
Magnetic Field ◽  
Circular Dichroism ◽  
External Magnetic Field ◽  
Time Reversal ◽  
Cuprate Superconductors ◽  
Magnetic Circular Dichroism ◽  
Magnetic Field Effects ◽  
Transmission Measurements ◽  
Circular Dichroïsm ◽  
The Magnetic Field

Reflection measurements on a one-domain single crystal of YBa 2 Cu 3 O 7-δ and transmission measurements on single crystals of Bi 2 Sr 2 CaCu 2 O 8 show a state of spontaneously broken symmetry below certain transition temperatures T s somewhat above the respective superconduction temperature T c . In both materials the sign of the effect can be controlled by an external magnetic field. In transmission measurements on films of YBa 2 Cu 3 O 7-δ near T s a remanent circular dichroism is observed after applying an external magnetic field. Furthermore, the films show a Curie-Weiss type increase of magnetic circular dichroism near T s . The magnetic field effects are considered as evidence for a state with broken time reversal symmetry below T s .

scholarly journals Ultralow-temperature device dedicated to soft X-ray magnetic circular dichroism experiments

2018 ◽  
Vol 25 (6) ◽  
pp. 1727-1735 ◽  
Author(s):  
J.-P. Kappler ◽  
E. Otero ◽  
W. Li ◽  
L. Joly ◽  
G. Schmerber ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Circular Dichroism ◽  
Synchrotron Radiation ◽  
Eddy Current ◽  
Magnetic Circular Dichroism ◽  
X Ray ◽  
Ultralow Temperature ◽  
X Ray Absorption ◽  
Circular Dichroïsm ◽  
The Magnetic Field

A new ultralow-temperature setup dedicated to soft X-ray absorption spectroscopy and X-ray magnetic circular dichroism (XMCD) experiments is described. Two experiments, performed on the DEIMOS beamline (SOLEIL synchrotron), demonstrate the outstanding performance of this new platform in terms of the lowest achievable temperature under X-ray irradiation (T = 220 mK), the precision in controlling the temperature during measurements as well as the speed of the cooling-down and warming-up procedures. Moreover, owing to the new design of the setup, the eddy-current power is strongly reduced, allowing fast scanning of the magnetic field in XMCD experiments; these performances lead to a powerful device for X-ray spectroscopies on synchrotron-radiation beamlines facilities.

Plasmonic circular dichroism in side-by-side oligomers of gold nanorods: the influence of chiral molecule location and interparticle distance

2015 ◽  
Vol 17 (12) ◽  
pp. 8187-8193 ◽  
Author(s):  
Shuai Hou ◽  
Hui Zhang ◽  
Jiao Yan ◽  
Yinglu Ji ◽  
Tao Wen ◽  
...  
Keyword(s):  
Circular Dichroism ◽  
Gold Nanorods ◽  
Interparticle Distance ◽  
Chiral Molecule ◽  
Highly Sensitive ◽  
Circular Dichroïsm

The CD signal of Au nanorod assemblies is highly sensitive to the chiral molecule location and the interparticle distance.

Remote Biodetection Method Using Circular Dichroism

1993 ◽  
Vol 47 (11) ◽  
pp. 1887-1891 ◽  
Author(s):  
David L. Rosen
Keyword(s):  
Circular Dichroism ◽  
Circular Polarization ◽  
Laser Light ◽  
New Method ◽  
Optical Elements ◽  
Biological Aerosols ◽  
Optical Table ◽  
Circular Dichroïsm ◽  
Aerosol Plume

This paper proposes a new method for remote biodetection and simulates it with a laboratory optical table experiment. The new method, called circular polarization transmissometry, uses laser light scattered from the ground to measure the circular dichroism in an aerosol plume. In the optical table experiment, a scatter plate simulated the ground, and solutions of camphoroquinone simulated the biological aerosols. The experiment showed that this biodetection method could work even in daylight. Optical elements with inherent birefringence caused an optical artifact background that was subtracted from the signal.

scholarly journals Discovery of weak magnetic fields in four DZ white dwarfs in the local 20 pc volume

2019 ◽  
Vol 630 ◽  
pp. A65 ◽  
Author(s):  
S. Bagnulo ◽  
J. D. Landstreet
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
White Dwarfs ◽  
Field Measurements ◽  
Weak Magnetic Fields ◽  
Polluted Atmosphere ◽  
Highly Sensitive ◽  
Cool White Dwarfs ◽  
The Magnetic Field ◽  
Made In

We report the discovery of weak magnetic fields in three white dwarfs within the local 20 pc volume (WD 0816−310, WD 1009−184, and WD 1532+129), and we confirm the magnetic nature of a fourth star (WD 2138−332) in which we had previously detected a field at a 3σ level. The spectra of all these white dwarfs are characterised by the presence of metal lines and lack of H and He lines, that is, they belong to the spectral class DZ. The polarisation signal of the Ca II H+K lines of WD 1009−184 is particularly spectacular, with an amplitude of 20% that is due to the presence of a magnetic field with an average line-of-sight component of 40 kG. We have thus established that at least 40% of the known DZ white dwarfs with an He-rich atmosphere contained in the 20 pc volume have a magnetic field, while further observations are needed to establish whether the remaining DZ white dwarfs in the same volume are magnetic or not. Metal lines in the spectra of DZ white dwarfs are thought to have originated by accretion from rocky debris, and it might be argued that a link exists between metal accretion and higher occurrence of magnetism. However, we are not able to distinguish whether the magnetic field and the presence of a polluted atmosphere have a common origin, or if it is the presence of metal lines that allows us to detect a higher frequency of magnetic fields in cool white dwarfs, which would otherwise have featureless spectra. We argue that the new highly sensitive longitudinal field measurements that we have made in recent years are consistent with the idea that the magnetic field appears more frequently in older than in younger white dwarfs.

Soft X-ray Magnetic Circular Dichroism of a CoFe/MnIr Exchange Bias Film under Pulsed High Magnetic Field

2011 ◽  
Vol 4 (6) ◽  
pp. 066602 ◽  
Author(s):  
Tetsuya Nakamura ◽  
Yasuo Narumi ◽  
Toko Hirono ◽  
Misaki Hayashi ◽  
Kenji Kodama ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Circular Dichroism ◽  
High Magnetic Field ◽  
Exchange Bias ◽  
Magnetic Circular Dichroism ◽  
X Ray ◽  
Pulsed High Magnetic Field ◽  
Circular Dichroïsm

Magnetic Generator with Automatic Gain Regulation in a Wireless Tracking System for a Capsule Endoscope

2013 ◽  
Vol 401-403 ◽  
pp. 1393-1396
Author(s):  
Xu Dong Guo ◽  
Chao Ruan ◽  
Bin Ge ◽  
Rong Guo Yan ◽  
Ying Liu
Keyword(s):  
Magnetic Field ◽  
Signal To Noise Ratio ◽  
Tracking System ◽  
Reference Value ◽  
Digital Signal ◽  
Measuring Method ◽  
Magnetic Sensor ◽  
Capsule Endoscope ◽  
The Magnetic Field ◽  
Magnetic Generator

To track a capsule endoscope, a novel measuring method based on alternating magnetic field is presented. The signal-to-noise ratio of the magnetic sensor decreases sharply with the increasing tracking distance. Thus, a magnetic generator with automatic gain regulation is designed to improve the localization precision. It is composed of a microcontroller, a DA converter, a timer, a waveform synthesis circuit, a power amplifier, a sequence control circuit and excitation coils. First, the wireless magnetic sensor measures the strength of the magnetic field produced by the magnetic generator. Via radio frequency communication, the measured result is feedback to the comparator of the microcontroller. According to a deviation obtained by comparing the measured results with the reference value, the microcontroller outputs a digital signal to the DA converter to control the magnitude of the exciting current. The prototype of the system was developed and the experiment was performed. The experiment shows that the magnetic field generator can automatically adjust the strength of the exciting signal.

Circular dichroism of graphene-based absorber in static magnetic field

2014 ◽  
Vol 115 (15) ◽  
pp. 154312 ◽  
Author(s):  
Min Wang ◽  
Yanqin Wang ◽  
Mingbo Pu ◽  
Chenggang Hu ◽  
Xiaoyu Wu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Circular Dichroism ◽  
Static Magnetic Field ◽  
Circular Dichroïsm
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