Tomczyk Michelle, Cheng Guanglei, Lee Hyungwoo, Lu Shicheng, Annadi Anil, Veazey Joshua P, Huang Mengchen, Irvin Patrick, Ryu Sangwoo, Eom Chang-Beom, Levy Jeremy
Department of Physics and Astronomy, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, USA.
Pittsburgh Quantum Institute, Pittsburgh, Pennsylvania 15260, USA.
Phys Rev Lett. 2016 Aug 26;117(9):096801. doi: 10.1103/PhysRevLett.117.096801. Epub 2016 Aug 22.
High-mobility complex-oxide heterostructures and nanostructures offer new opportunities for extending the paradigm of quantum transport beyond the realm of traditional III-V or carbon-based materials. Recent quantum transport investigations with LaAlO_{3}/SrTiO_{3}-based quantum dots reveal the existence of a strongly correlated phase in which electrons form spin-singlet pairs without becoming superconducting. Here, we report evidence for the micrometer-scale ballistic transport of electron pairs in quasi-1D LaAlO_{3}/SrTiO_{3} nanowire cavities. In the paired phase, Fabry-Perot-like quantum interference is observed, in sync with conductance oscillations observed in the superconducting regime (at a zero magnetic field). Above a critical magnetic field B_{p}, the electron pairs unbind and the conductance oscillations shift with the magnetic field. These experimental observations extend the regime of ballistic electronic transport to strongly correlated phases.
高迁移率复合氧化物异质结构和纳米结构为将量子输运范式扩展到传统III-V族或碳基材料领域之外提供了新机遇。最近对基于LaAlO₃/SrTiO₃的量子点进行的量子输运研究揭示了一种强关联相的存在，在该相中电子形成自旋单重态对而不发生超导。在此，我们报告了在准一维LaAlO₃/SrTiO₃纳米线腔中电子对微米尺度弹道输运的证据。在配对相中，观察到类似法布里-珀罗的量子干涉，与在超导 regime（零磁场下）观察到的电导振荡同步。高于临界磁场Bₚ时，电子对解离，电导振荡随磁场移动。这些实验观察结果将弹道电子输运的 regime扩展到了强关联相。
