Far-infrared antiferromagnetic resonance inGd2CuO4

Infrared phonon anomaly and magnetic excitations in single-crystal Cu3Bi(SeO3)2OMiller1, Stephens2, Martin3 et al. 2012Phys. Rev. B

“…Taking the average d.c. index of refraction to be 3 in the ab plane, we determine that our magnetic excitation corresponds to an optical conductivity of about 0.23 Ω −1 cm −1 (σ 1 = c 4π nα), which is roughly the same strength as other reported single-magnon excitations. [26][27][28] Electromagnons, which have been extensively studied in a number of rare-earth manganites, are observed to possess optical conductivities of at least a factor of 10 larger. 9,29 Although this method of comparison does not yield objective certainty, we can further support its conclusion by employing optical sum rule analysis on our measured reflectance data.…”

Dark photon searches with atomic transitions

“…axion detector such as [30]). In any case, the experimental data are very limited, with very few measurements done for each material, in specific conditions and usually for very small samples [38][39][40]. Nevertheless, these results are quite encouraging because all of these materials exhibit energy levels in the desired range, and most of them respond in a promising way to magnetic fields and low temperature conditions.…”

Infrared phonon anomaly and magnetic excitations in single-crystal Cu$_{3}$Bi(SeO$_{3}$)$_{2}$O$_{2}$Cl

“…Taking the average d.c. index of refraction to be 3 in the ab plane, we determine that our magnetic excitation corresponds to an optical conductivity of about 0.23 Ω −1 cm −1 (σ 1 = c 4π nα), which is roughly the same strength as other reported single-magnon excitations. [25][26][27] Electromagnons, which have been extensively studied in a number of rare-earth manganites, are observed to possess optical conductivities of at least a factor of 10 larger. 9,28 Although this method of comparison does not yield objective certainty, we can further support its conclusion by employing optical sum rule analysis on our measured reflectance data.…”