Electron-spin filter based on a novel magnetic nanostructure with zero average magnetic field

Magnetic field sensitive fluorescence from irradiated propylene carbonate solutions indicates the existence of previously unobserved radical cations formed from the solvent molecules.

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A 4 × 4 array multichannel magnetic stimulation system using submillimeter sized planar square spiral coils: The spatial distribution of electromagnetic field

International Journal of Applied Electromagnetics and Mechanics ◽

10.3233/jae-210139 ◽

2022 ◽

pp. 1-18

Author(s):

Lei Tian ◽

Limei Song ◽

Yu Zheng ◽

Jinhai Wang

Keyword(s):

Magnetic Field ◽

Electromagnetic Field ◽

Spatial Distribution ◽

Field Strength ◽

Electric Field ◽

Magnetic Stimulation ◽

Spiral Coil ◽

Average Magnetic Field ◽

Stimulation System ◽

Field Strengths

Multi-coil magnetic stimulation has advantages over single-coil magnetic stimulation, such as more accurate targeting and larger stimulation range. In this paper, a 4 × 4 array multichannel magnetic stimulation system based on a submillimeter planar square spiral coil is proposed. The effects of multiple currents with different directions on the electromagnetic field strength and the focusing zone of the array-structured magnetic stimulation system are studied. The spatial distribution characteristics of the electromagnetic field are discussed. In addition, a method is proposed that can predict the spatial distributions of the electric and magnetic fields when currents in different directions are applied to the array-structured magnetic stimulation system. The study results show that in the section of z = 2 μm, the maximum and average magnetic field strengths of the array-structured magnetic stimulation system are 6.39 mT and 2.68 mT, respectively. The maximum and average electric field strengths are 614.7 mV/m and 122.82 mV/m, respectively, where 84.39% of the measured electric field values are greater than 73 mV/m. The average magnetic field strength of the focusing zone, i.e., the zone in between the two coils, is 3.38 mT with a mean square deviation of 0.18. Therefore, the array-structured multi-channel magnetic stimulation system based on a planar square spiral coil can have a small size of 412 μm × 412 μm × 1.7 μm, which helps improving the spatial distribution of electromagnetic field and increase the effectiveness of magnetic stimulation. The main contribution of this paper is a method for designing multichannel micro-magnetic stimulation devices.

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Comment on “Magnetic-Field-Induced Low-Energy Spin Excitations inYBa2Cu4O8Measured by High FieldGd3+Electron Spin Resonance”

Physical Review Letters ◽

10.1103/physrevlett.87.209701 ◽

2001 ◽

Vol 87 (20) ◽

Cited By ~ 1

Author(s):

G.-q. Zheng ◽

Y. Kitaoka ◽

W. G. Clark

Keyword(s):

Magnetic Field ◽

Electron Spin Resonance ◽

Electron Spin ◽

Low Energy ◽

Spin Resonance ◽

Spin Excitations

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The temperature dependence of free electron susceptibility

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1935.0214 ◽

1935 ◽

Vol 152 (877) ◽

pp. 672-692 ◽

Cited By ~ 42

Keyword(s):

Magnetic Field ◽

Electron Spin ◽

Free Electron ◽

Low Temperatures ◽

Electron Gas ◽

Spin Effect ◽

Degenerate State ◽

Diamagnetic Contribution ◽

The Moment ◽

Diamagnetic Effect

One of the earliest applications of the Fermic-Dirac statistics was that of pauli to the treatment of the paramagnetism, due to the electron spin, of an electron gas. The result he obtained, for low temperatures, may be put in the form M p = 3/2 Nμ 2 H/ε 0 , where M p is the total magnetic moment due to the spin effect, N the number of electrons, μ the Bohr magneton, and ε 0 the maximum electron energy in the completely degenerate state. It was later shown by Landau that electrons, apart from the spin effect, gave a diamagnetic contribution to the susceptibility. The diamagnetic effect (which is zero on a classical basis) arises from the discreteness of the energy states of an electron in a magnetic field. For low temperatures the result obtained is M D = -½ Nμ 2 H/ε 0 , where M D is the diamagnetic contribution to the moment. The spin effect was further considered by Bloch, who gave, as a higher approximation at low temperatures, M P = 3/2 Nμ 2 H/ε 0 {1-π 2 /12( k T/ε 0 ) 2 }.

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