We investigated the dependence of T C and magnetoresistance (MR) on gate voltages ( V G ) in the 20-nm-thick high-quality La 0.6 Sr 0.4 MnO 3 (LSMO) Hall bar gated by ionic liquid (more Reversible Ferromagnetic Phase Transition in ElectrodeGated ManganitesBin Cui , Cheng Song , * Guangyue Wang , Yinuo Yan , Jingjing Peng , Jinghui Miao , Haijun Mao , Fan Li , Chao Chen , Fei Zeng , and Feng Pan * The electronic phase transition has been considered as a dominant factor in the phenomena of colossal magnetoresistance, metal-insulator transition, and exchange bias in correlated electron systems. However, the effective manipulation of the electronic phase transition has remained a challenging issue. Here, the reversible control of ferromagnetic phase transition in manganite fi lms through ionic liquid gating is reported. Under different gate voltages, the formation and annihilation of an insulating and magnetically hard phase in the magnetically soft matrix, which randomly nucleates and grows across the fi lm instead of initiating at the surface and spreading to the bottom, is directly observed. This discovery provides a conceptually novel vision for the electric-fi eld tuning of phase transition in correlated oxides. In addition to its fundamental signifi cance, the realization of a reversible metalinsulator transition in colossal magnetoresistance materials will also further the development of four-state memories, which can be manipulated by a combination of electrode gating and the application of a magnetic fi eld.

The antigen-presenting molecule MR1 (MHC class I-related protein 1) presents metabolite antigens derived from microbial vitamin B2 synthesis to activate mucosal-associated invariant T (MAIT) cells. Key aspects of this evolutionarily conserved pathway remain uncharacterized, including where MR1 acquires ligands and what accessory proteins assist ligand binding. We answer these questions by using a fluorophore-labeled stable MR1 antigen analog, a conformation-specific MR1 mAb, proteomic analysis, and a genome-wide CRISPR/Cas9 library screen. We show that the endoplasmic reticulum (ER) contains a pool of two unliganded MR1 conformers stabilized via interactions with chaperones tapasin and tapasin-related protein. This pool is the primary source of MR1 molecules for the presentation of exogenous metabolite antigens to MAIT cells. Deletion of these chaperones reduces the ER-resident MR1 pool and hampers antigen presentation and MAIT cell activation. The MR1 antigen-presentation pathway thus co-opts ER chaperones to fulfill its unique ability to present exogenous metabolite antigens captured within the ER.

Electrical control of the exchange spring in antiferromagnetic metals is obtained in [Co/Pt]/IrMn Hall devices by using an ionic liquid, where the exchange spring could transfer the "force" and enable a deeper modulation depth in the IrMn. This work provides a new approach toward electrical modulation of the spin structures in metallic antiferromagnets, which should be significant in advancing the development of low-power-consumption antiferromagnet (AFM) spintronics.

While vanadium oxides have many attractive pseudocapacitive features for energy storage, their applications are severely limited by the poor electronic conductivity and low specific surface area. To overcome these limitations, a scalable, free‐standing film electrode composed of intertwined V2O5 nanowires and carbon nanotubes (CNTs) using a blade coating process has been prepared. The unique architecture of this hybrid electrode greatly facilitates electronic transport along CNTs while maintaining rapid ion diffusion within V2O5 nanowires and fast electron transfer across the V2O5/CNTs interfaces. When tested in a neutral aqueous electrolyte, this hybrid film electrode demonstrates a volumetric capacitance of ≈460 F cm−3. Moreover, a symmetric capacitor based on two identical film electrodes displays a wide operation voltage window of 1.6 V, delivering a volumetric energy density as high as 41 Wh L−1.