Related papers: Quantum anomalous Hall effect in Mn doped HgTe qua…
The single-particle energy spectrum of a two-dimensional electron gas in a perpendicular magnetic field consists of equally-spaced spin-split Landau levels, whose degeneracy is proportional to the magnetic field strength. At integer and…
The anomalous Hall effect, observed in conducting ferromagnets with broken time-reversal symmetry, offers the possibility to couple spin and orbital degrees of freedom of electrons in ferromagnets. In addition to charge, the anomalous Hall…
We discuss the orbital effect of a tilted magnetic field on the quantum Hall effect in parabolic quantum wells. Many-body states realized at the fractional 1/3 and 1/2 filling of the second electronic subband are studied using finite-size…
We present a theory of the Anomalous Hall Effect (AHE) in ferromagnetic (Ga,Mn)As in the regime when conduction is due to phonon-assisted hopping of holes between localized states in the impurity band. We show that the microscopic origin of…
We investigate non-linear magneto-transport in a Hall bar device made from a strained InGaAs/InP quantum well: a material system with attractive spintronic properties. From extensive maps of the longitudinal differential resistance (r_xx)…
Quantum anomalous Hall effect(QAHE) can only be realized at extremely low temperatures in magnetically doped topological insulators(TIs) due to limitations inherent with the doping precess. In an effort to boost the quantization temperature…
We use magnetotransport in dual-gated magnetic topological insulator heterostructures to map out a phase diagram of the topological Hall and quantum anomalous Hall effects as a function of the chemical potential (primarily determined by the…
A two-dimensional array of quantum dots in a magnetic field is considered. The electrons in the quantum dots are described as unitary random matrix ensembles. The strength of the magnetic field is such that there is half a flux quantum per…
We report on the scaling behavior of V-doped (Bi,Sb)$_2$Te$_3$ samples in the quantum anomalous Hall regime for samples of various thickness. While previous quantum anomalous Hall measurements showed the same scaling as expected from a…
Consistent with prior qualitative expectations for group IV-VI topological crystalline insulators, this work demonstrates, based on band structure and Chern number calculations, that Pb$_{1-x}$Sn$_x$Se/(PbSe)$_{1-y}$(EuS)$_y$ quantum wells…
The helical edge states in a quantum spin Hall insulator are presumably protected by time- reversal symmetry. However, even in the presence of magnetic field which breaks time-reversal symmetry, the helical edge conduction can still exist,…
We have measured magnetotransport at half-filled high Landau levels in a quantum well with two occupied electric subbands. We find resistivities that are {\em isotropic} in perpendicular magnetic field but become strongly {\em anisotropic}…
We report a continuous phase transition between quantum-anomalous-Hall and trivial-insulator phases in a magnetic topological insulator upon magnetization rotation. The Hall conductivity transits from one plateau of quantized Hall…
We report experimental studies of conductance and magnetoconductance of GaAs/AlGaAs quantum well structures where both wells and barriers are doped by acceptor impurity Be. Temperature dependence of conductance demonstrate a non-monotonic…
As in conventional ferromagnets, the Hall resistivity rho_xy of a La_{2/3}(Ca,Pb)_{1/3}MnO_3 single crystal exhibits both ordinary and anomalous contributions at low temperature. However, these contributions, unexpectedly, have opposite…
We examine the magnetic field driven insulator-quantum Hall-insulator transitions of the two dimensional hole gas in a Ge/SiGe quantum well. We observe direct transitions between low and high magnetic field insulators and the $\nu=1$…
The integer quantum anomalous Hall (QAH) effect is a lattice analog of the quantum Hall effect at zero magnetic field. This striking transport phenomenon occurs in electronic systems with topologically nontrivial bands and spontaneous…
A quantum phase transition arises from competition between different ground states and is typically accessed by varying a single physical parameter near absolute zero temperature. The quantum anomalous Hall (QAH) effect with high Chern…
The interplay between magnetism and strong electron correlation in magnetic materials discerns a variety of intriguing topological features. Here, we report a systematic investigation of the magnetic, thermodynamic, and electrical transport…
Quantum anomalous Hall effect (QAHE), which generates dissipation-less edge current without external magnetic field, is observed in magnetic-ion doped topological insulators (TIs), such as Cr- and V-doped (Bi,Sb)2Te3. The QAHE emerges when…