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High sensitivity of the Kβ fluorescence spectrum to electronic state is widely used to investigate spin and oxidation state of first-row transition-metal compounds. However, the complex electronic structure results in overlapping spectral features, and the interpretation may be hampered by ambiguity in resolving the spectrum into components representing different electronic states. Here, we tackle this difficulty with a nonlinear resonant inelastic X-ray scattering (RIXS) scheme, where we leverage sequential two-photon absorption to realize an inverse process of the Kβ emission, and measure the successive Kα emission. The nonlinear RIXS reveals two-dimensional (2D) Kβ-Kα fluorescence spectrum of copper metal, leading to better understanding of the spectral feature. We isolate 3 d -related satellite peaks in the 2D spectrum, and find good agreement with our multiplet ligand field calculation. Our work not only advances the fluorescence spectroscopy, but opens the door to extend RIXS into the nonlinear regime. X-ray fluorescence spectroscopy is a powerful tool to investigate atomic properties. Here the authors report a two-dimensional fluorescence spectrum of copper metal using X-ray nonlinear scattering and find two-hole satellite feature resulting from atomic transitions.

In the rapidly growing field of spintronics, simultaneous control of electronic and magnetic properties is essential, and the perspective of building novel phases is directly linked to the control of tuning parameters, for example, thickness and doping. Looking at the relevant effects in interface-driven spintronics, the reduced symmetry at a surface and interface corresponds to a severe modification of the overlap of electron orbitals, that is, to a change of electron hybridization. Here we report a chemically and magnetically sensitive depth-dependent analysis of two paradigmatic systems, namely La 1− x Sr x MnO 3 and (Ga,Mn)As. Supported by cluster calculations, we find a crossover between surface and bulk in the electron hybridization/correlation and we identify a spectroscopic fingerprint of bulk metallic character and ferromagnetism versus depth. The critical thickness and the gradient of hybridization are measured, setting an intrinsic limit of 3 and 10 unit cells from the surface, respectively, for (Ga,Mn)As and La 1− x Sr x MnO 3 , for fully restoring bulk properties. Surface versus bulk effects in electronic structure of spintronics materials are crucial to their applications but are yet well understood. Here the authors experimentally determine the critical thickness that defines the crossover of electron hybridization between surface and bulk for two prototype spintronics materials.

We combine time resolved pump-probe Magneto-Optical Kerr Effect and Photoelectron Spectroscopy experiments supported by theoretical analysis to determine the relaxation dynamics of delocalized electrons in half-metallic ferromagnetic manganite \\(La_{1-x}Sr_{x}MnO_{3}\\). We observe that the half-metallic character of \\(La_{1-x}Sr_{x}MnO_{3}\\) determines the timescale of both the electronic phase transition and the quenching of magnetization, revealing a quantum isolation of the spin system in double exchange ferromagnets extending up to hundreds of picoseconds. We demonstrate the use of time-resolved hard X-ray photoelectron spectroscopy (TR-HAXPES) as a unique tool to single out the evolution of strongly correlated electronic states across a second-order phase transition in a complex material.

Valence instability is a key ingredient of the unusual properties of f electron materials, yet a clear understanding is lacking as it involves a complex interplay between f electrons and conduc- tion states. Here we propose a unified picture of pressure-induced valence transition in Sm and Yb monochalcogenides, considered as model system for mixed valent 4f-electron materials. Using high-resolution x-ray absorption spectroscopy, we show that the valence transition is driven by the promotion of a 4f electron specifically into the lowest unoccupied (LU) 5d t2g band. We demonstrate with a promotional model that the nature of the transition at low pressures is intimately related to the density of states of the LU band, while at high pressures it is governed by the hybridization strength. These results set a new standard for the generic understanding of valence fluctuations in f-electron materials.

A periodic \\(4a \\times 4a\\) density of states (DOS) modulation (a \"checkerboard pattern\") was observed with STM in \\(\\rm Na_{x}Ca_{2-x}CuO_2Cl_2\\) (NCCOC) [T. Hanaguri \\emph{et al.}, Nature \\textbf{430}, 1001 (2004)]. Its periodicity is the same as that of the \"stripe\" charge order observed with neutron scattering in \\(\\rm La_{1.875}Ba_{0.125}CuO_4\\) (LBCO) [J. M. Tranquada \\emph{et al.}, Nature \\textbf{429}, 534 (2004)] and \\(\\rm La_{1.48}Nd_{0.4}Sr_{0.12}CuO_4\\) (LNSCO) [J. M. Tranquada \\emph{et al.}, Phys. Rev. B \\textbf{54}, 7489 (1996)]. An obvious question is whether the \"stripes\" are actually \"checkers\". Unfortunately, because NCCOC samples are small and LBCO samples do not cleave, neutron and STM measurements cannot be carried out on the same system. To determine the relationship between stripes and checkers we used resonant soft x-ray scattering (RSXS), previously applied to LBCO [P. Abbamonte \\emph{et al.}, Nature Physics \\textbf{1}, 155 (2005)], to study single crystals of NCCOC. No evidence was seen for a \\(4a \\times 4a\\) DOS modulation, indicating that the checkerboard effect is not directly related to the stripe modulation in LBCO. Our measurements suggest either glassy electronic behavior or the existence of a surface-nucleated phase transition in NCCOC [S. E. Brown \\emph{et al.}, Phys. Rev. B \\textbf{71}, 224512 (2005)].

We report the bulk sensitive Hard X-ray (hv=5.95keV) core level photoemission spectroscopy to investigate the intrinsic electronic structure of strained (La0.85Ba0.15)MnO3 thin films. In a 20nm thick well-strained film with strongly enhanced ferromagnetism, a new sharp satellite peak appeared at the low energy site of the Mn 2p3/2 main peak, whereas a broader signal was observed for the unstrained film with 300nm thickness. Cluster calculations revealed that the intensity corresponded to the density of the state at the Fermi level relating to the magnitude of the ferromagnetic order. The satellite intensity also agreed quantitatively with the square of the magnetization.

The planet Venus is covered by thick clouds of sulfuric acid that move westwards because the entire upper atmosphere rotates much faster than the planet itself. At the cloud tops, about 65 km in altitude, small-scale features are predominantly carried by the background wind at speeds of approximately 100 m s −1 . In contrast, planetary-scale atmospheric features have been observed to move slightly faster or slower than the background wind, a phenomenon that has been interpreted to reflect the propagation of planetary-scale waves. Here we report the detection of an interhemispheric bow-shaped structure stretching 10,000 km across at the cloud-top level of Venus in middle infrared and ultraviolet images from the Japanese orbiter Akatsuki. Over several days of observation, the bow-shaped structure remained relatively fixed in position above the highland on the slowly rotating surface, despite the background atmospheric super rotation. We suggest that the bow-shaped structure is the result of an atmospheric gravity wave generated in the lower atmosphere by mountain topography that then propagated upwards. Numerical simulations provide preliminary support for this interpretation, but the formation and propagation of a mountain gravity wave remain difficult to reconcile with assumed near-surface conditions on Venus. We suggest that winds in the deep atmosphere may be spatially or temporally more variable than previously thought. The upper atmosphere of Venus rotates much faster than the planet itself. An anomalous stationary structure observed by the Akatsuki mission at the cloud tops of Venus could be an atmospheric gravity wave induced by mountain topography below.

Background The efficacy of adjuvant therapy for patients with cervical cancer with intermediate risk (CC‐IR) remains controversial. We examined the impact of adjuvant therapy on survival outcomes in patients with CC‐IR and evaluated the heterogeneous treatment effects (HTEs) of adjuvant therapies based on clinicopathologic characteristics. Methods We retrospectively analyzed a previous Japanese nationwide cohort of 6192 patients with stage IB–IIB cervical cancer who underwent radical hysterectomy. We created two pairs of propensity score‐matched treatment/control groups to investigate the treatment effects of adjuvant therapies: (1) adjuvant therapy versus non‐adjuvant therapy; (2) chemotherapy versus radiotherapy conditional on adjuvant therapy. Multivariate analyses with treatment interactions were performed to evaluate the HTEs. Results Among the 1613 patients with CC‐IR, 619 and 994 were in the non‐treatment and treatment groups, respectively. Survival outcomes did not differ between the two groups: 3‐year progression‐free survival (PFS) rates were 88.1% and 90.3% in the non‐treatment and treatment groups, respectively (p = 0.199). Of the patients in the treatment group, 654 and 340 received radiotherapy and chemotherapy, respectively. Patients who received chemotherapy had better PFS than those who received radiotherapy (3‐year PFS, 90.9% vs. 82.9%, p = 0.010). Tumor size was a significant factor that affected the treatment effects of chemotherapy; patients with large tumors gained better therapeutic effects from chemotherapy than those with small tumors. Conclusion Adjuvant therapy is optional for some patients with CC‐IR; however, chemotherapy can be recommended as adjuvant therapy, particularly for patients with large tumors.