Nanjing University

About: Nanjing University is a education organization based out in Nanjing, China. It is known for research contribution in the topics: Catalysis & Population. The organization has 85961 authors who have published 105504 publications receiving 2289036 citations. The organization is also known as: NJU & Nanking University.

Pressure-driven dome-shaped superconductivity and electronic structural evolution in tungsten ditelluride.

Abstract: Tungsten ditelluride has attracted intense research interest due to the recent discovery of its large unsaturated magnetoresistance up to 60 T. Motivated by the presence of a small, sensitive Fermi surface of 5d electronic orbitals, we boost the electronic properties by applying a high pressure, and introduce superconductivity successfully. Superconductivity sharply appears at a pressure of 2.5 GPa, rapidly reaching a maximum critical temperature (Tc) of 7 K at around 16.8 GPa, followed by a monotonic decrease in Tc with increasing pressure, thereby exhibiting the typical dome-shaped superconducting phase. From theoretical calculations, we interpret the low-pressure region of the superconducting dome to an enrichment of the density of states at the Fermi level and attribute the high-pressure decrease in Tc to possible structural instability. Thus, tungsten ditelluride may provide a new platform for our understanding of superconductivity phenomena in transition metal dichalcogenides.

Cell-Specific and pH-Activatable Rubyrin-Loaded Nanoparticles for Highly Selective Near-Infrared Photodynamic Therapy against Cancer

Abstract: Spatiotemporal control of singlet oxygen (1O2) release is a major challenge for photodynamic therapy (PDT) against cancer with high therapeutic efficacy and minimum side effects. Here a selenium-rubyrin (NMe2Se4N2)-loaded nanoparticle functionalized with folate (FA) was designed and synthesized as an acidic pH-activatable targeted photosensitizer. The nanoparticles could specifically recognize cancer cells via the FA-FA receptor binding and were selectively taken up by cancer cells via receptor-mediated endocytosis to enter lysosomes, in which NMe2Se4N2 was activated to produce 1O2. The pH-controllable release of 1O2 specially damaged the lysosomes and thus killed cancer cells in a lysosome-associated pathway. The introduction of selenium into the rubyrin core enhanced the 1O2 generation efficiency due to the heavy atom effect, and the substitution of dimethylaminophenyl moiety at meso-position led to the pH-controllable activation of NMe2Se4N2. Under near-infrared (NIR) irradiation, NMe2Se4N2 possessed h...

Observation of topological superconductivity on the surface of an iron-based superconductor

Abstract: Topological superconductors are predicted to host exotic Majorana states that obey non-Abelian statistics and can be used to implement a topological quantum computer. Most of the proposed topological superconductors are realized in difficult-to-fabricate heterostructures at very low temperatures. By using high-resolution spin-resolved and angle-resolved photoelectron spectroscopy, we find that the iron-based superconductor FeTe 1– x Se x ( x = 0.45; superconducting transition temperature T c = 14.5 kelvin) hosts Dirac-cone–type spin-helical surface states at the Fermi level; the surface states exhibit an s-wave superconducting gap below T c . Our study shows that the surface states of FeTe 0.55 Se 0.45 are topologically superconducting, providing a simple and possibly high-temperature platform for realizing Majorana states.

Substitution-induced phase transition and enhanced multiferroic properties of Bi1−xLaxFeO3 ceramics

Abstract: Single-phase, insulating Bi1−xLaxFeO3 (BLFOx, x=0.05, 0.10, 0.15, 0.20, 0.30, and 0.40) ceramics were prepared. An obvious phase transition from rhombohedral to orthorhombic phase was observed near x=0.30. It is found that the phase transition destructs the spin cycloid of BiFeO3 (BFO), and therefore, releases the locked magnetization and enhances magnetoelectric interaction. As a result, improved multiferroic properties of the BLFO0.30 ceramics with remnant polarization and magnetization (2Pr and 2Mr) of 22.4μC∕cm2 and 0.041emu∕g, respectively, were established.