Widespread applications of magnetic devices require an efficient means to manipulate the local magnetization. One mechanism is the electrical spin-transfer torque associated with electron-mediated spin currents; however, this suffers from substantial energy dissipation caused by Joule heating. We experimentally demonstrated an alternative approach based on magnon currents and achieved magnon-torque–induced magnetization switching in Bi2Se3/antiferromagnetic insulator NiO/ferromagnet devices at room temperature. The magnon currents carry spin angular momentum efficiently without involving moving electrons through a 25-nanometer-thick NiO layer. The magnon torque is sufficient to control the magnetization, which is comparable with previously observed electrical spin torque ratios. This research, which is relevant to the energy-efficient control of spintronic devices, will invigorate magnon-based memory and logic devices.

Curcumin, a naturally occurring polyphenolic compound from Curcuma longa, has long been used in folk medicine as an antiinflammatory remedy in Asian countries. Endometriosis is a chronic gynecological inflammatory disorder in which immune system deregulation may play a role in its initiation and progression. A number of mediators, including cell adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1); proinflammatory cytokines such as tumour necrosis factor-α (TNF-α), interleukin-1 (IL-1), IL-6 and IL-8; and chemokines such as monocyte chemotactic protein-1 (MCP-1), play key roles in the pathogenesis of endometriosis. The aim of our study was to explore the effect of curcumin on the expression of these critical molecules in human ectopic endometriotic stromal cells isolated from women with endometriosis. Endometriotic stromal cells treated with curcumin showed marked suppression of TNF-α-induced mRNA expression of ICAM-1 and VCAM-1. Curcumin treatment also significantly decreased the TNF-α-induced cell surface and total protein expression of ICAM-1 and VCAM-1 in a dose-dependent manner. In addition, treatment of endometriotic stromal cells with curcumin markedly inhibited TNF-α-induced secretion of IL-6, IL-8 and MCP-1. Furthermore, curcumin inhibited the activation of transcription factor NF-κB, a key regulator of inflammation, in human endometriotic stromal cells. These findings suggest that curcumin may have potential therapeutic uses in the prevention and treatment of endometriosis.

The generation and detection of ultrafast spin current, preferably reaching a frequency up to terahertz, is the core of spintronics. Studies have shown that the Weyl semimetal WTe 2 is of great potential in generating spin currents. However, the prior studies have been limited to the static measurements with the inplane spin orientation. In this work, we demonstrate a picosecond spin-photocurrent in a Td-WTe 2 thin film via a terahertz time domain spectroscopy with a circularly polarized laser excitation. The anisotropic dependence of the circular photogalvanic effect (CPGE) in the terahertz emission reveals that the picosecond spinphotocurrent is generated along the rotational asymmetry a-axis. Notably, the generated spins are aligned along the out-of-plane direction under the light normally incident to the film surface, which provides an efficient means to manipulate magnetic devices with perpendicular magnetic anisotropy. A spin-splitting band induced by intrinsic inversion symmetry breaking enables the manipulation of a spin current by modulating the helicity of the laser excitation. Moreover, CPGE nearly vanishes at a transition temperature of ∼175 K due to the carrier compensation. Our work provides an insight into the dynamic behavior of the anisotropic spin-photocurrent of Td-WTe 2 in terahertz frequencies and shows a great potential for the future development of terahertz-spintronic devices with Weyl semimetals.

Terahertz emission spectroscopy (TES) has recently played an important role in unveiling the spin dynamics at a terahertz (THz) frequency range. So far, ferromagnetic/nonmagnetic heterostructures have been intensively studied as THz sources. Compensated magnets such as a ferrimagnet (FIM) and antiferromagnet (AFM) are other types of magnetic materials with interesting spin dynamics. In this work, TES from compensated magnetic heterostructures including CoGd FIM alloy or IrMn AFM layers is studied. Systematic measurements on composition and temperature dependences of THz emission from CoGd/Pt bilayer structures are conducted. It is found that the emitted THz field is determined by the net spin polarization of the laser‐induced spin current rather than the net magnetization. The temperature robustness of the FIM‐based THz emitter is also demonstrated. On the other hand, an AFM plays a different role in THz emission. The IrMn/Pt bilayer shows negligible THz signals, whereas Co/IrMn induces sizable THz outputs, indicating that IrMn is not a good spin current generator, but a good detector. These results not only suggest that a compensated magnet can be utilized for robust THz emission, but also provide a new approach to study the magnetization dynamics especially near the magnetization compensation point.

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generation. However, no single emitter is able to cover a broadband spectrum ranging from 0.1 to 10 THz. At present, PCAs are the most efficient THz emitters for the 0.1-4 THz spectral band while the performance drops dramatically at higher frequencies (> 4 THz). [25][26][27] Compared with PCAs, some EO crystals and air plasmas have an excellent performance at higher frequencies, whereas the performance in the lower THz frequency range is relatively poor. Thus, combining two different THz emission mechanisms to achieve a broader spectrum has long been thought. However, this approach has been technically limited by the mismatched phase inducing a destructive interference as well as the challenges of heterogeneous integration of different technologies.During the past several years, the development in the field of spintronics reveals a new possibility for the generation and manipulation of spin and charge currents. [28,29] Spin-to-charge conversion has been discovered as a new mechanism for ultrafast photocurrent generation. The metallic spintronic THz emitter based on the inverse spin Hall effect (ISHE) is fast becoming a superior candidate among conventional THz sources. [30][31][32][33][34][35] THz emitters with heavy metal (HM)/ferromagnet (FM) bilayer structures have been demonstrated as broadband THz sources and a gapless spectrum covering up to 10 THz has been reported. [32,36,37] On the other hand, the limited performance of HM/FM based THz emitters in the lower THz frequency range (0.1-0.5 THz) restricts its capacity for a broader range of applications. However, the nanoscale (in terms of thickness) nature of spintronic THz emitter makes it possible to merge with other conventional emitters, while maintaining the similar phase emission leading to a constructive interference of two THz emitters. A negligible dispersion happens when the optical wave propagates through a spintronics device with a thickness in nanometers, and thus no significant phase mismatch occurs between the THz emission from spintronic devices and the other mechanism. Therefore, an ultra-broadband spectrum of this hybrid THz emitter can be achieved on a single chip, which has not been explored so far.In this work, we demonstrate a new type of ultra-broadband spintronic THz emitters assisted by a current modulation on a semiconductor. We observe a significant enhancement of the THz signals in the lower THz frequency range (0.1-0.5 THz), of which the power is 2-3 orders of magnitude larger than that of typical ISHE-based THz emitters. In particular, this An ultra-broadband terahertz (THz) emitter covering a wide range of frequencies from 0.1 to 10 THz is highly desired for spectroscopy applications. So far, spintronic THz emitters have been proven as one class of efficient THz sources with a broadband spectrum while the performance in the lower THz frequency range (0.1-0.5 THz) limits its applications. In this work, a novel concept of a current-enhanced broad spectrum from spintronic THz emitters combined with semiconductor materials is demo...

This study showed decreased expressions of VEGF and visfatin in the third trimester placental bed of pregnancies with PE compared with the normotensive controls. This result suggests that decreased expression of these angiogenic factors in placental bed may be associated with the pathogenesis of PE.

These findings show that interleukin-8 is one of the neutrophil survival factors in the peritoneal fluid of endometriosis patients and that an unidentified survival factor is also present in the plasma of patients with endometriosis.