Intrinsic Nonlinear Hall Detection of the Néel Vector for Two-Dimensional Antiferromagnetic Spintronics.

The respective unique merit of antiferromagnets and two-dimensional (2D) materials in spintronic applications inspires us to exploit 2D antiferromagnetic spintronics. However, the detection of the Néel vector in 2D antiferromagnets remains a great challenge because the measured signals usually decrease significantly in the 2D limit. Here we propose that the Néel vector of 2D antiferromagnets can be efficiently detected by the intrinsic nonlinear Hall (INH) effect which exhibits unexpected significant signals. As a specific example, we show that the INH conductivity of the monolayer manganese chalcogenides MnX (X=S, Se, Te) can reach the order of nm·mA/V^{2}, which is orders of magnitude larger than experimental values of paradigmatic antiferromagnetic spintronic materials. The INH effect can be accurately controlled by shifting the chemical potential around the band edge, which is experimentally feasible via electric gating or charge doping. Moreover, we explicitly demonstrate its 2π-periodic dependence on the Néel vector orientation based on an effective k·p model. Our findings enable flexible design schemes and promising material platforms for spintronic memory device applications based on 2D antiferromagnets.

Enhancement of superconductivity in organic-inorganic hybrid topological materials.

Inducing or enhancing superconductivity in topological materials is an important route toward topological superconductivity. Reducing the thickness of transition metal dichalcogenides (e.g. WTe2 and MoTe2) has provided an important pathway to engineer superconductivity in topological matters. However, such monolayer sample is difficult to obtain, unstable in air, and with extremely low Tc. Here we report an experimentally convenient approach to control the interlayer coupling to achieve tailored topological properties, enhanced superconductivity and good sample stability through organic-cation intercalation of the Weyl semimetals MoTe2 and WTe2. The as-formed organic-inorganic hybrid crystals are weak topological insulators with enhanced Tc of 7.0 K for intercalated MoTe2 (0.25 K for pristine crystal) and 2.3 K for intercalated WTe2 (2.8 times compared to monolayer WTe2). Such organic-cation intercalation method can be readily applied to many other layered crystals, providing a new pathway for manipulating their electronic, topological and superconducting properties.

[Adaptability of cucumber plug seedlings to daytime temperature].

Cucumber plug seedlings were cultured in a phytotron to study their responses to different daytime temperature. The daytime temperature was controlled at 30 degrees C, 27 degrees C, 24 degrees C, 21 degrees C, 18 degrees C and 15 degrees C, and the night temperature was at 15 degrees C, with the thickness and length of hypocotyl, length and width of the first and the second leaves, dry matter accumulation of above- and underground parts, leaf moisture content, and leaf chlorophyll fluorescence parameters measured. Principal component analysis and clustering analysis were made to analyze the seedling quality under different temperature treatment. There existed significant differences in the test growth indices among different treatments, with the seedling quality decreased at the daytime temperature 24 degrees C > 21 degrees C > 27 degrees C > 30 degrees C > 18 degrees C > 15 degrees C. All the daytime/nighttime temperature treatments could be classified into three groups, i.e., optimum temperature (24 degrees C/15 degrees C), appropriate temperature (21 degrees C/15 degrees C), and inappropriate temperature, and the inappropriate temperature could be further subdivided into two groups, i.e., high-temperature inhibition (27 degrees C/15 degrees C, 30 degrees C/15 degrees C) and low-temperature inhibition (15 degrees C/15 degrees C, 18 degrees C/15 degrees C).