Efeito fotomagnético

O efeito fotomagnético é um efeito quântico teórico descoberto pelos pesquisadores Samuel L. Oliveira e Stephen C. Rand na Universidade de Michigan 2007–2011.^[1]^[2]^[3]^[4] Os pesquisadores descobriram uma poderosa interação magnética entre o campo magnético dinâmico dos fótons e o momento magnético de certos átomos de materiais isoladores que é 100 milhões de vezes mais forte do que anteriormente previsto. Sob as circunstâncias adequadas, o efeito dos campos magnéticos dos fótons é tão forte quanto o seu campo elétrico, como em células solares.

A descoberta é uma surpresa, porque não é fácil derivar o forte efeito magnético das equações físicas e, portanto, indicar que esse efeito da mecânica quântica seria suficientemente significante. Por isso, o efeito fotomagnético foi negligenciado por mais de 100 anos.

Os pesquisadores calcularam teoricamente que luz incoerente, como a luz solar, é quase tão eficiente quanto a luz laser para ser convertida pelo efeito fotomagnético.

A intensidade luminosa deve ser de 10 milhões de watts por centímetro quadrado, mas os pesquisadores buscarão novos materiais fotomagnéticos que possam trabalhar com intensidades mais baixas.

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Referências

↑ April 13, 2011, ns.umich.edu: Solar power without solar cells: A hidden magnetic effect of light could make it possible
↑ University of Michigan (2011, April 14). Solar power without solar cells: A hidden magnetic effect of light could make it possible. ScienceDaily Quote: "..."You could stare at the equations of motion all day and you will not see this possibility. We've all been taught that this doesn't happen," said Rand, an author of a paper on the work published in the Journal of Applied Physics. "It's a very odd interaction. That's why it's been overlooked for more than 100 years."..."
↑ Apr 21, 2011, physicsworld.com: Solar power without solar cells
↑ «Optically-induced charge separation and terahertz emission in unbiased dielectrics». Journal of Applied Physics. 109. 064903 páginas. Bibcode:2011JAP...109f4903F. doi:10.1063/1.3561505. ...A magneto-electric power generation scheme has been proposed that relies on displacement currents in insulators, and avoids both the absorption and the electron-hole pair production that typify semiconducting solar cells... (referred reference: «Intense Nonlinear Magnetic Dipole Radiation at Optical Frequencies: Molecular Scattering in a Dielectric Liquid». Physical Review Letters. 98. Bibcode:2007PhRvL..98i3901O. doi:10.1103/PhysRevLett.98.093901. ...Large magnetic response is very unexpected at optical frequencies, and should lead to the discovery of new magneto-optical phenomena and the realization of low-loss homogeneous optical media with negative refractive indices... )

[1] April 13, 2011, ns.umich.edu: Solar power without solar cells: A hidden magnetic effect of light could make it possible

[2] University of Michigan (2011, April 14). Solar power without solar cells: A hidden magnetic effect of light could make it possible. ScienceDaily Quote: "..."You could stare at the equations of motion all day and you will not see this possibility. We've all been taught that this doesn't happen," said Rand, an author of a paper on the work published in the Journal of Applied Physics. "It's a very odd interaction. That's why it's been overlooked for more than 100 years."..."

[3] Apr 21, 2011, physicsworld.com: Solar power without solar cells

[4] «Optically-induced charge separation and terahertz emission in unbiased dielectrics». Journal of Applied Physics. 109. 064903 páginas. Bibcode:2011JAP...109f4903F. doi:10.1063/1.3561505. ...A magneto-electric power generation scheme has been proposed that relies on displacement currents in insulators, and avoids both the absorption and the electron-hole pair production that typify semiconducting solar cells... (referred reference: «Intense Nonlinear Magnetic Dipole Radiation at Optical Frequencies: Molecular Scattering in a Dielectric Liquid». Physical Review Letters. 98. Bibcode:2007PhRvL..98i3901O. doi:10.1103/PhysRevLett.98.093901. ...Large magnetic response is very unexpected at optical frequencies, and should lead to the discovery of new magneto-optical phenomena and the realization of low-loss homogeneous optical media with negative refractive indices... )

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