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Oxide transistor is the basic device to construct the oxide electronic circuit that is the backing to develop integrated oxide electronics with high efficiency and low power consumption. By growing the perovskite oxide integrated layers and tailoring them to lead semiconducting functions at their interfaces, the development of oxide transistors may be able to perform. We realize a kind of p-i-n type integrated layers consisting of an n-type cuprate superconductor, p-type colossal magnetoresistance manganite, and a ferroelectric barrier (i). From this, bipolar transistors were fabricated at the back-to-back p-i-n junctions, for which the Schottky emission and p-n junction barriers, as well as the ferroelectric polarization, were integrated into the interfaces to control the transport properties; a preliminary but distinct current gain greater than 1.6 at input current of microampers order was observed. These results present a real possibility to date for developing bipolar all perovskite oxide transistors. [ABSTRACT FROM AUTHOR]

The electronic nematic phase is characterized as an ordered state of matter with rotational symmetry breaking, and has been well studied in the quantum Hall system and the high-Tc superconductors, regardless of cuprate or pnictide family. The nematic state in high-Tc systems often relates to the structural transition or electronic instability in the normal phase. Nevertheless, the electronic states below the superconducting transition temperature is still an open question. With high-resolution scanning tunneling microscope measurements, direct observation of vortex core in FeSe thin films revealed the nematic superconducting state by Song et al. Here, motivated by the experiment, we construct the extended Ginzburg–Landau free energy to describe the elliptical vortex, where a mixed s-wave and d-wave superconducting order is coupled to the nematic order. The nematic order induces the mixture of two superconducting orders and enhances the anisotropic interaction between the two superconducting orders, resulting in a symmetry breaking from C4 to C2. Consequently, the vortex cores are stretched into an elliptical shape. In the equilibrium state, the elliptical vortices assemble a lozenge-like vortex lattice, being well consistent with experimental results. Superconductivity: multiple orders couple to produce elliptical vortex Theorists construct the extended Ginzburg-Landau free energy to explain the elliptical superconducting vortex, where multiple orders are coupled. A team led by Da-Chuan Lu and Jun Li from Nanjing University in China theoretically studied the nematic superconducting state, which is characterized by elliptical vortices, reported in a recent experiment. They construct the extended Ginzburg-Landau free energy by implementing finite element method to the time-dependent Ginzburg-Landau equations with open boundary conditions. The method describes the elliptical vortex, where a mixing of superconducting orders couple with a nematic order. The coupling further enhances the anisotropic interaction between superconducting orders and results in a four-fold to two-fold rotational symmetry breaking. The elliptical vortices assemble a lozenge-like vortex lattice, which is consistent with experimental results. [ABSTRACT FROM AUTHOR]