Yafis Barlas
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Yafis Barlas has a total of 14 co-authors. Here are the top co-authors by number of shared publications:
- Chun Ning Lau
Department of Physics and Astronomy, University of California, Riverside, Riverside, California 92521, USA
2 shared publications D. Smirnov
National High Magnetic Field Laboratory 32310 Tallahassee FL
2 shared publicationsD. Tran
Department of Physics and Astronomy University of California 91765 Riverside Riverside CA
2 shared publicationsK. Myhro
Department of Physics and Astronomy University of California 91765 Riverside Riverside CA
2 shared publicationsN. Gillgren
Department of Physics and Astronomy University of California 91765 Riverside Riverside CA
2 shared publications- Roger K. Lake
University of California, Riverside
2 shared publications
Latest Publications
- Open Access
- 15 February 2017
- Published by American Physical Society (APS) in Physical Review B
- Vol. 95 (7) , 075418
Effect of intervalley interaction on band topology of commensurate graphene/EuO heterostructures
Recent experiments demonstrating proximity induced ferromagnetism in graphene motivate this study of commensurate graphene/EuO heterostructures. Due to the commensurability of graphene with the (111)-EuO layer, graphene's Dirac points are mapped to the point of the commensurate Brillouin zone. The Eu atoms not only induce proximity exchange on the graphene layer, but they also introduce intervalley interactions resulting in a nonlinear dispersion at . We develop a model Hamiltonian, consistent with the lattice symmetries, that includes proximity induced exchange splitting, spin-orbit coupling, and intervalley interactions with parameters fitted to ab initio calculations. The intervalley interaction opens up a trivial gap preventing the system from crossing into a nontrivial state. The model Hamiltonian is analyzed to determine the conditions under which the heterostructures can exhibit topologically nontrivial bands.- 15 February 2017
- Published by American Physical Society (APS) in Physical Review B
- Vol. 95 (7) , 075418
Open AccessEffect of intervalley interaction on band topology of commensurate graphene/EuO heterostructures
Recent experiments demonstrating proximity induced ferromagnetism in graphene motivate this study of commensurate graphene/EuO heterostructures. Due to the commensurability of graphene with the (111)-EuO layer, graphene's Dirac points are mapped to the point of the commensurate Brillouin zone. The Eu atoms not only induce proximity exchange on the graphene layer, but they also introduce intervalley interactions resulting in a nonlinear dispersion at . We develop a model Hamiltonian, consistent with the lattice symmetries, that includes proximity induced exchange splitting, spin-orbit coupling, and intervalley interactions with parameters fitted to ab initio calculations. The intervalley interaction opens up a trivial gap preventing the system from crossing into a nontrivial state. The model Hamiltonian is analyzed to determine the conditions under which the heterostructures can exhibit topologically nontrivial bands. - Open Access
Multicomponent Quantum Hall Ferromagnetism and Landau Level Crossing in Rhombohedral Trilayer Graphene
Using transport measurements, we investigate multicomponent quantum Hall (QH) ferromagnetism in dual-gated rhombohedral trilayer graphene (r-TLG), in which the real spin, orbital pseudospin and layer pseudospins of the lowest Landau level form spontaneous ordering. We observe intermediate quantum Hall plateaus, indicating a complete lifting of the degeneracy of the zeroth Landau level (LL) in the hole-doped regime. In charge neutral r-TLG, the orbital degeneracy is broken first, and the layer degeneracy is broken last and only the in presence of an interlayer potential U. In the phase space of U and filling factor, we observe an intriguing hexagon pattern, which is accounted for by a model based on crossings between symmetry-broken LLs.
Open AccessMulticomponent Quantum Hall Ferromagnetism and Landau Level Crossing in Rhombohedral Trilayer Graphene
Using transport measurements, we investigate multicomponent quantum Hall (QH) ferromagnetism in dual-gated rhombohedral trilayer graphene (r-TLG), in which the real spin, orbital pseudospin and layer pseudospins of the lowest Landau level form spontaneous ordering. We observe intermediate quantum Hall plateaus, indicating a complete lifting of the degeneracy of the zeroth Landau level (LL) in the hole-doped regime. In charge neutral r-TLG, the orbital degeneracy is broken first, and the layer degeneracy is broken last and only the in presence of an interlayer potential U. In the phase space of U and filling factor, we observe an intriguing hexagon pattern, which is accounted for by a model based on crossings between symmetry-broken LLs.
- 10 December 2015
- Published by American Chemical Society (ACS) in Nano Letters
- Vol. 16 (1) , 227-231
Multicomponent Quantum Hall Ferromagnetism and Landau Level Crossing in Rhombohedral Trilayer Graphene
Using transport measurements, we investigate multicomponent quantum Hall (QH) ferromagnetism in dual-gated rhombohedral trilayer graphene (r-TLG) in which the real spin, orbital pseudospin, and layer pseudospins of the lowest Landau level form spontaneous ordering. We observe intermediate QH plateaus, indicating a complete lifting of the degeneracy of the zeroth Landau level (LL) in the hole-doped regime. In charge neutral r-TLG, the orbital degeneracy is broken first, and the layer degeneracy is broken last and only in the presence of an interlayer potential U⊥. In the phase space of U⊥ and filling factor ν, we observe an intriguing “hexagon” pattern, which is accounted for by a model based on crossings between symmetry-broken LLs.
- 10 December 2015
- Published by American Chemical Society (ACS) in Nano Letters
- Vol. 16 (1) , 227-231
Multicomponent Quantum Hall Ferromagnetism and Landau Level Crossing in Rhombohedral Trilayer Graphene
Using transport measurements, we investigate multicomponent quantum Hall (QH) ferromagnetism in dual-gated rhombohedral trilayer graphene (r-TLG) in which the real spin, orbital pseudospin, and layer pseudospins of the lowest Landau level form spontaneous ordering. We observe intermediate QH plateaus, indicating a complete lifting of the degeneracy of the zeroth Landau level (LL) in the hole-doped regime. In charge neutral r-TLG, the orbital degeneracy is broken first, and the layer degeneracy is broken last and only in the presence of an interlayer potential U⊥. In the phase space of U⊥ and filling factor ν, we observe an intriguing “hexagon” pattern, which is accounted for by a model based on crossings between symmetry-broken LLs.
- Open Access
Proximity induced quantum anomalous Hall effect in graphene/EuO hetero-structures
In a heterostructure of graphene and the ferromagnetic insulator EuO, the Eu atoms induce proximity exchange and inter-valley interactions in the graphene layer. Constrained by the lattice symmetries, and guided by ab initio calculations, a model Hamiltonian is constructed that describes the low-energy bands. Band parameters such as proximity induced exchange splitting, spin orbit coupling, and inter-valley interaction are determined. Calculations of the Chern number identify the conditions under which the hetero-structures exhibit topologically non-trivial bands that give rise to the quantum anomalous Hall effect with a Hall conductivity of $\sigma_{xy} = 2 e^2/h$.Open AccessProximity induced quantum anomalous Hall effect in graphene/EuO hetero-structures
In a heterostructure of graphene and the ferromagnetic insulator EuO, the Eu atoms induce proximity exchange and inter-valley interactions in the graphene layer. Constrained by the lattice symmetries, and guided by ab initio calculations, a model Hamiltonian is constructed that describes the low-energy bands. Band parameters such as proximity induced exchange splitting, spin orbit coupling, and inter-valley interaction are determined. Calculations of the Chern number identify the conditions under which the hetero-structures exhibit topologically non-trivial bands that give rise to the quantum anomalous Hall effect with a Hall conductivity of $\sigma_{xy} = 2 e^2/h$.