The electronic structure and spin-dependent conductance of a magnetic junction consisting of two Fe-doped carbon nanotubes and a C60 molecule are investigated using a first-principles approach that combines the density functional theory with the nonequilibrium Greens function technique. The tunneling magnetoresistance ratio is found to be 11%. The density of states and transmission coefficient through the molecular junction are analyzed and compared to layered magnetic tunneling junctions. Our findings suggest new possibilities for experiments and for future technology.

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In this paper, combined with infinite time-evolving block decimation (iTEBD) algorithm and Belltype inequalities, we investigate multi-partite quantum nonlocality in an infinite one-dimensional quantum spin-1 2 XXZ system. High hierarchy of multipartite nonlocality can be observed in the gapless phase of the model, meanwhile only the lowest hierarchy of multipartite nonlocality is observed in most regions of the gapped anti-ferromagnetic phase. Thereby, Bell-type inequalities disclose different correlation structures in the two phases of the system. Furthermore, at the infinite-order QPT (or Kosterlitz-Thouless QPT) point of the model, the correlation measures always show a local minimum value, regardless of the length of the subchains. It indicates that relatively low hierarchy of multi-partite nonlocality would be observed at the infinite-order QPT point in a Belltype experiment. The result is in contrast to the existing results of the second-order QPT in the one-dimensional XY model, where multi-partite nonlocality with the highest hierarchy has been observed. Thus, multi-partite nonlocality provides us an alternative perspective to distinguish between these two kinds of QPTs. Reliable clues for the existence of tripartite quantum entanglement have also been found.

We report first principles calculations of transport properties of the all-oxide La2/3Sr1/3MnO3/MgO/SrRuO3 magnetic tunnel junctions. A sizeable rectifying behavior which can be enhanced by increasing the MgO barrier thickness is predicted theoretically. For the device with 13 layers of MgO barrier, the positive current is about two orders of magnitude larger than the reverse leakage current. The rectifying behavior arises from the symmetry-filtering properties of the MgO barrier. This rectifying effect which is totally dominated by quantum tunneling could be used to design faster quantum devices such as tunnel diode and tunnel transistor.

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