Influence of Coulomb interaction on the Aharonov-Bohm effect in an electronic Fabry-Perot interferometer
Stephane Ngo Dinh and Dmitry A. Bagrets
We study the role of Coulomb interaction in an electronic Fabry-Perot interferometer (FPI) realized with chiral edge states in the integer quantum Hall regime in the limit of weak backscattering. Assuming that a compressible Coulomb island in a bulk region of the FPI is formed, we develop a capacita ... [Phys. Rev. B 85, 073403 ] published .
Green's function method for line defects and gapless modes in topological insulators: Beyond the semiclassical approach
Ken Shiozaki and Satoshi Fujimoto
Defects that appear in heterostructure junctions involving topological insulators are sources of gapless modes governing the low-energy properties of the systems, as recently elucidated by Teo and Kane [Phys. Rev. B 82, 115120 (2010)]. A standard approach for the calculation of topological invariant ... [Phys. Rev. B 85, 085409 ] published .
Quantum anomalous Hall effect with tunable Chern number in magnetic topological insulator film
Hua Jiang, Zhenhua Qiao, Haiwen Liu, and Qian Niu
We study the possibility of realizing quantum anomalous Hall (QAH) effect with tunable Chern number through doping magnetic elements in a multilayer topological insulator film. We find that high Chern number QAH phases exist in ideal neutral samples and can make transition to another QAH phase direc ... [Phys. Rev. B 85, 045445 ] published .
Quantum Hall effect in bottom-gated epitaxial graphene grown on the C-face of SiC
B. Jouault, N. Camara, B. Jabakhanji, A. Caboni, C. Consejo et al.
We demonstrate that the carrier concentration of epitaxial graphene devices grown on the C-face of a SiC substrate is efficiently modulated by a buried gate. The gate is fabricated via the implantation of nitrogen atoms in the SiC crystal. The charge neutrality point is observed close to gate voltag ... [Appl. Phys. Lett. 100, 052102 (2012)] published Mon Jan 30, 2012.
Simulating Z topological insulators with cold atoms in a one-dimensional optical lattice
Feng Mei, Shi-Liang Zhu, Zhi-Ming Zhang, C. H. Oh, and N. Goldman
We propose an experimental scheme to simulate and detect the properties of time-reversal invariant topological insulators, using cold atoms trapped in one-dimensional bichromatic optical lattices. This system is described by a one-dimensional Aubry-Andre model with an additional SU(2) gauge structur ... [Phys. Rev. A 85, 013638 ] published .
Quantized nu=5/2 State in a Two-Subband Quantum Hall System
J. Nuebler, B. Friess, V. Umansky, B. Rosenow, M. Heiblum et al.
The evolution of the fractional quantum Hall state at filling 5/2 is studied in density tunable two-dimensional electron systems formed in wide wells in which it is possible to induce a transition from single- to two-subband occupancy. In 80 and 60 nm wells, the quantum Hall state at 5/2 filling of ... [Phys. Rev. Lett. 108, 046804 ] published .
Single charge sensing and transport in double quantum dots fabricated from commercially grown Si/SiGe heterostructures
C. Payette, K. Wang, P. J. Koppinen, Y. Dovzhenko, J. C. Sturm et al.
We perform quantum Hall measurements on three types of commercially available modulation-doped Si/SiGe heterostructures to determine their suitability for depletion gate defined quantum dot devices. By adjusting the growth parameters, we are able to achieve electron gases with charge densities 13 x ... [Appl. Phys. Lett. 100, 043508 (2012)] published Wed Jan 25, 2012.
Topological Hubbard Model and Its High-Temperature Quantum Hall Effect
Titus Neupert, Luiz Santos, Shinsei Ryu, Claudio Chamon, and Christopher Mudry
The quintessential two-dimensional lattice model that describes the competition between the kinetic energy of electrons and their short-range repulsive interactions is the repulsive Hubbard model. We study a time-reversal symmetric variant of the repulsive Hubbard model defined on a planar lattice: ... [Phys. Rev. Lett. 108, 046806 ] published .
Competing Topological Orders in the nu=12/5 Quantum Hall State
Parsa Bonderson, Adrian E. Feiguin, Gunnar Moller, and J. K. Slingerland
We provide numerical evidence that a p-ip paired Bonderson-Slingerland (BS) non-Abelian hierarchy state is a strong candidate for the observed nu=12/5 quantum Hall plateau. We confirm the existence of a gapped incompressible nu=12/5 quantum Hall state with shift S=2 on the sphere, matching that of t ... [Phys. Rev. Lett. 108, 036806 ] published .
Cross-Correlated Responses of Topological Superconductors and Superfluids
Kentaro Nomura, Shinsei Ryu, Akira Furusaki, and Naoto Nagaosa
We study nontrivial responses of topological superconductors and superfluids to the temperature gradient and rotation of the system. In two-dimensional gapped systems, the Streda formula for the electric Hall conductivity is generalized to the thermal Hall conductivity. Applying this formula to the ... [Phys. Rev. Lett. 108, 026802 ] published .
Quantum phase transitions in ultrathin films of three-dimensional topological insulators in the presence of an electrostatic potential and a Zeeman field
Huichao Li, L. Sheng, and D. Y. Xing
We investigate transport properties of the surface states of three-dimensional topological insulator thin films in the presence of an electrostatic potential gamma and a spin-splitting Zeeman field g. It is shown that there exist a quantum pseudospin Hall phase, a quantum anomalous Hall phase, and a ... [Phys. Rev. B 85, 045118 ] published .
Galois conjugates of topological phases
M. H. Freedman, J. Gukelberger, M. B. Hastings, S. Trebst, M. Troyer et al.
Galois conjugation relates unitary conformal field theories and topological quantum field theories (TQFTs) to their nonunitary counterparts. Here we investigate Galois conjugates of quantum double models, such as the Levin-Wen model. While these Galois-conjugated Hamiltonians are typically non-Hermi ... [Phys. Rev. B 85, 045414 ] published .
Dirac model of an isolated graphene antidot in a magnetic field
Jesper Goor Pedersen and Thomas Garm Pedersen
We consider a single graphene antidot, modeled via a circularly symmetric mass term in the Dirac Hamiltonian, in the presence of an external magnetic field. We derive analytical expressions for the eigenstate spinors, and use these to formulate an eigenvalue condition for the system. We find that el ... [Phys. Rev. B 85, 035413 ] published .
Impact of electron heating on the equilibration between quantum Hall edge channels
Nicola Paradiso, Stefan Heun, Stefano Roddaro, Lucia Sorba, Fabio Beltram et al.
When two separately contacted quantum Hall (QH) edge channels are brought into interaction, they can equilibrate their imbalance via scattering processes. In this work, we use a tunable QH circuit to implement a junction between copropagating edge channels, the length of which can be controlled with ... [Phys. Rev. B 84, 235318 ] published .
Proximity-induced superconductivity in topological BiTeSe and BiSe films: Robust zero-energy bound state possibly due to Majorana fermions
G. Koren, T. Kirzhner, E. Lahoud, K. B. Chashka, and A. Kanigel
Point contact conductance measurements on topological BiTeSe and BiSe films reveal a signature of superconductivity below 23 K. In particular, critical current dips and a robust zero-bias conductance peak are observed. The latter suggests the presence of zero-energy bound states that could be assign ... [Phys. Rev. B 84, 224521 ] published .
Exact results for finite quantum Hall systems of electrons at filling factor one: Disk geometry
Orion Ciftja
We obtain exact analytical expressions for the total energy per particle and related quantities corresponding to a finite quantum Hall system of electrons in a disk geometry when filling factor of the Landau level is one. Such exact results apply to finite systems of electrons with an arbitrary numb ... [J. Math. Phys. 52, 122105 (2011)] published Thu Dec 29, 2011.
Exactly soluble models for fractional topological insulators in two and three dimensions
Michael Levin, F. J. Burnell, Maciej Koch-Janusz, and Ady Stern
We construct exactly soluble lattice models for fractionalized, time-reversal-invariant electronic insulators in two and three dimensions. The low-energy physics of these models is exactly equivalent to a noninteracting topological insulator built out of fractionally charged fermionic quasiparticles ... [Phys. Rev. B 84, 235145 ] published .
Two-Dimensional Imaging of Gauge Fields in Optical Lattices
Jaeyoon Cho and M. S. Kim
We propose a scheme to generate an arbitrary Abelian vector potential for atoms trapped in a two-dimensional optical lattice. By making the optical lattice potential dependent on the atomic state, we transform the problem into that of a two-dimensional imaging. It is shown that an arbitrarily fine p ... [Phys. Rev. Lett. 107, 260402 ] published .
Topological nodal semimetals
A. A. Burkov, M. D. Hook, and Leon Balents
We present a study of nodal-semimetal phases in which nondegenerate conduction and valence bands touch at points (the Weyl semimetal) or lines (the line-node semimetal) in three-dimensional momentum space. We discuss a general approach to such states by perturbation of the critical point between a n ... [Phys. Rev. B 84, 235126 ] published .
Skyrmion quantum numbers and quantized pumping in two-dimensional topological chiral magnets
Bohm-Jung Yang and Naoto Nagaosa
We investigate the general conditions to achieve the adiabatic charge and spin polarizations and quantized pumping in 2D magnetic insulators possessing inhomogeneous spin structures. In particular, we focus on the chiral ferrimagnetic insulators that are generated via spontaneous symmetry breaking f ... [Phys. Rev. B 84, 245123 ] published .
Tunable interactions and phase transitions in Dirac materials in a magnetic field
Z. Papic, D. A. Abanin, Y. Barlas, and R. N. Bhatt
A partially filled Landau level (LL) hosts a variety of correlated states of matter with unique properties. The ability to control these phases requires tuning the effective electron interactions within a LL, which has been difficult to achieve in GaAs-based structures. Here we consider a class of D ... [Phys. Rev. B 84, 241306 ] published .