Multicavity X-Ray Fabry-Perot Resonance with Ultrahigh Resolution and Contrast

Abstract

Realization of x-ray Fabry-Perot (FP) resonance in back-Bragg-reflection crystal cavities has been proposed and explored for many years, but to date no satisfactory performance has been achieved. Here we show that single-cavity crystal resonators intrinsically have limited finesse and efficiency. To break this limit, we demonstrate that monolithic multicavity resonators with equal-width cavities and specific plate thickness ratios can generate ultrahigh-resolution FP resonance with high efficiency, steep peak tails, and ultrahigh contrast simultaneously. The resonance mechanism is similar to that of sequentially cascaded single-cavity resonators. The ultranarrow-bandwidth FP resonance is anticipated to have various applications, including modern ultrahigh-resolution or precision x-ray monochromatization, spectroscopy, coherence purification, coherent diffraction, phase contrast imaging, etc.

Precursor state of skyrmions in MnSi: a heat capacity study

“…Skyrmion lattice (SkX) is classified as a typical topological excitation. The formation of SkX is reported in thin films of B20 transition metal compounds, Fe 0.5 Co 0.5 Si [2], FeGe [3,4] where as the precursor states as A-phase are observed in single crystalline Fe 0.8 Co 0.2 Si [5], MnSi [1,6,7] and FeGe [8,9]. Such observation is also reported in thin films as well as bulk form of multiferroic insulating compound Cu 2 OSeO 3 [10,11].…”

Investigation of chiral phases near helical ordering temperature in MnSi

“…The physics of skyrmions and chiral modulations in the cubic helimagnets has gained great importance, in recent times. Generally, chiral modulations in non-centrosymmetric magnets (chiral, cones, and skyrmions) can be separated into two fundamentally different classes, (i) regular modulations with fixed magnetization amplitude and rotational modes arising in a wide temperature interval [1][2][3] and (ii) precursor modulations with a soften magnetization amplitude in the vicinity of longrange magnetic ordering, T c [4][5][6][7]. MnSi is a weak itinerant metal that orders helically below 30 K (T c ∼ 29.7 K) due to Dzyaloshinkskii-Moriya (DM) interactions as a result of the lack of inversion symmetry [8][9][10].…”

Topological Hall effect in antiferromagnetically coupled SrRuO3/La0.7Sr0.3MnO3 epitaxial heterostructures

“…THE has been observed in metallic magnets with chiral crystal structure and skyrmionic phases such as B20 compounds (e.g., MnSi) [2,3,6], pointing out that THE is a powerful tool for probing the skyrmion phase. Hall effect measurements of epitaxial FeGe grown on Si(111) substrates revealed a strong topological Hall effect after subtracting out the ordinary and anomalous Hall effects, demonstrating the formation of high density skyrmions between 5 and 275 K, in zero-magnetic field [7,8]. However, careful analyses of the Hall effect data measured on epitaxial films of MnSi/Si(111), corroborated with transmission electron microscopy observations of the magnetic domains, demonstrated that the additional contributions to the anomalous Hall resistivity, taken previously as a THE effect induced by skyrmions, are not due to the skyrmion magnetic phase but rather to the conical phase [9].…”