The quantum anomalous Hall effect (QAHE) is a fundamental quantum transport phenomenon that manifests as a quantized transverse conductance in response to a longitudinally applied electric field in the absence of an external magnetic field, and promises to have immense application potentials in future dissipation-less quantum electronics. Here we present a novel kinetic pathway to realize the QAHE at high temperatures by n-p codoping of three-dimensional topological insulators. We provide proof-of-principle numerical demonstration of this approach using vanadium-iodine (V-I) codoped Sb2Te3 and demonstrate that, strikingly, even at low concentrations of ∼2% V and ∼1% I, the system exhibits a quantized Hall conductance, the tell-tale hallmark of QAHE, at temperatures of at least ∼ 50 Kelvin, which is three orders of magnitude higher than the typical temperatures at which it has been realized so far. The proposed approach is conceptually general and may shed new light in experimental realization of high-temperature QAHE. Two-dimensional electron systems (2DESs) are versatile playgrounds for complex quantum transport phenomena that are of interest both from fundamental and application points of view. One prominent example is the quantum Hall effect (QHE) [1, 2], a quantum analogue of the classical Hall effect, whereby the application of a magnetic field to a 2DES results in the quantization of the transverse conductance and a vanishing longitudinal conductance. Crucially, the mechanisms underlying this phenomenon are the formation of an insulating bulk and remarkable chiral conducting edge states (Fig. 1a). This striking unidirectionality makes backscattering impossible, and renders transport along these edge states remarkably robust against any impurities [3,4]. This robustness essentially renders the edges of 2DESs manifesting the QHE as perfectly conducting one-dimensional (1D) wires, which would be of great interest as potential building blocks, such as interconnects between chips, in dissipation-less electronics. However, a major constraint for practical use of this fundamental quantum transport phenomenon is the requirement of very strong magnetic fields, which is impractical for realistic applications.Realizing the quantum anomalous Hall effect (QAHE) would circumvent this problem because it manifests the same hallmark features as the QHE, but does not require the application of an external magnetic field [5]. The reason why the QAHE does not require the application of an external field is because the latter's role is played by an intricate cooperation between the intrinsic magnetism that breaks the time-reversal symmetry and spin-orbit coupling in the 2D (quasi-2D) insulating host material. Initial proposals for realizing the QAHE were based on honeycomb lattice models [5]. Since then, especially after the experimental discoveries of graphene (with an inherent honeycomb lattice structure) [6] and topological insulators (TIs) [7,8], much effort has been made to exploring new platforms for realizing QAHE in th...

The transport properties of CrI₃/h-BN/n·CrI₃ (n = 1, 2, 3, 4) MTJs under positive bias voltages exhibit an interesting odd-even effect. Significant tunneling magnetoresistance, a perfect spin filtering effect and remarkable negative differential resistance were obtained.

The combined roles of oxygen vacancy and electron doping in mediating local and nonlocal magnetic ordering of Fe doped in In 2 O 3 and Co doped in ZnO have been investigated within first-principles density functional theory. We first show theoretically that two magnetic dopants can be stabilized energetically around an oxygen vacancy, and are ferromagnetically coupled to form a local magnetic polaron.Furthermore, electron doping plays the elegant dual role of further enhancing the ferromagnetic stability of a local polaron, and more crucially, mediating the nonlocal 2 magnetic coupling between two polarons. We finally provide experimental evidence supporting these strong predictions.