Fotomagnetisk effekt

Den fotomagnetiske effekt er en kvantemekanisk effekt opdaget af forskerne Samuel L. Oliveira og Stephen C. Rand ved University of Michigan omkring 2007-2011. ^[1] ^[2] ^[3] Forskerne har opdaget en kraftig magnetisk interaktion mellem fotonernes dynamiske magnetiske felt – og visse isolatormaterialers atomers magnetiske moment, som er 100 millioner gange stærkere end tidligere forventet. Under de rette omstændigheder, er fotonernes magnetfelts effekt ligeså stærkt som deres elektriske felt – som f.eks. i solceller.

Opdagelsen er en overraskelse, da man ikke umiddelbart ud af de fysiske ligninger kan udlede, at denne kvantemekaniske effekt ville være interessant nok. Derfor er den fotomagnetiske effekt blevet overset i mere end 100 år.

Forskerne har teoretisk beregnet at inkoherent lys som f.eks. sollys, er næsten ligeså effektivt som laserlys, til at blive omsat via den fotomagnetiske effekt.

I 2011 skulle effekttætheden dog være 10 millioner watt per kvadratcentimeter, men forskerne søger efter nye fotomagnetiske materialer, som kan nøjes med væsentligt lavere intensiteter.

Måske kan det gøre solenergi-til-elektrisk energi omsætningen endnu billigere end i dag.

Kilder/referencer

^ University of Michigan (2011, April 14). Solar power without solar cells: A hidden magnetic effect of light could make it possible. ScienceDaily Arkiveret 23. november 2011 hos Wayback Machine Citat: "..."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". Arkiveret fra originalen 13. november 2011. Hentet 22. april 2011.
^ Abonnement krævet: J. Appl. Phys. 109, 064903 (2011); doi:10.1063/1.3561505, published online 21 March 2011: Optically-induced charge separation and terahertz emission in unbiased dielectrics (Webside ikke længere tilgængelig), pdf (Webside ikke længere tilgængelig) Citat: "...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...", (refererede kilder: Phys. Rev. Lett. 98, 093901 (2007), DOI:10.1103/PhysRevLett.98.093901: Intense Nonlinear Magnetic Dipole Radiation at Optical Frequencies: Molecular Scattering in a Dielectric Liquid Citat: "...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...")

Se også

Fotoelektrisk effekt

[1] University of Michigan (2011, April 14). Solar power without solar cells: A hidden magnetic effect of light could make it possible. ScienceDaily Arkiveret 23. november 2011 hos Wayback Machine Citat: "..."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."..."

[2] "Apr 21, 2011, physicsworld.com: Solar power without solar cells". Arkiveret fra originalen 13. november 2011. Hentet 22. april 2011.

[3] Abonnement krævet: J. Appl. Phys. 109, 064903 (2011); doi:10.1063/1.3561505, published online 21 March 2011: Optically-induced charge separation and terahertz emission in unbiased dielectrics (Webside ikke længere tilgængelig), pdf (Webside ikke længere tilgængelig) Citat: "...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...", (refererede kilder: Phys. Rev. Lett. 98, 093901 (2007), DOI:10.1103/PhysRevLett.98.093901: Intense Nonlinear Magnetic Dipole Radiation at Optical Frequencies: Molecular Scattering in a Dielectric Liquid Citat: "...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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