492 citations · 2k across the 27 of their papers we have counts for
24 papers · 1 filter
Extended linear-in- resistivity due to electron-phason scattering in moiré superlattices
Héctor Ochoa, Rafael M. Fernandes
Due to its incommensurate nature, moiré superlattices host not only acoustic phonons but also another type of soft collective modes called phasons. Here, we investigate the impact…
Electric backaction on moiré mechanics
Héctor Ochoa
A lattice mismatch between Van der Waals layers produces a moiré pattern and a subsequent electron band reconstruction. When the bilayer is charged, the sliding motion of one layer…
Degradation of phonons in disordered moiré superlattices
Héctor Ochoa, Rafael M. Fernandes
The elastic collective modes of a moiré superlattice arise not from vibrations of a rigid crystal but from the relative displacement between the constituent layers. Despite their s…
Self-induced spin-orbit torques in metallic ferromagnets
Hector Ochoa, Ricardo Zarzuela, Yaroslav Tserkovnyak
We present a phenomenological theory of spin-orbit torques in a metallic ferromagnet with spin-relaxing boundaries. The model is rooted in the coupled diffusion of charge and spin…
Nonlinear twistoptics at symmetry-broken interfaces
Kaiyuan Yao, Nathan R. Finney, Jin Zhang +17
Broken symmetries induce strong nonlinear optical responses in materials and at interfaces. Twist angle can give complete control over the presence or lack of inversion symmetry at…
Strain-induced excitonic instability in twisted bilayer graphene
Hector Ochoa
The low-energy bands of twisted bilayer graphene form Dirac cones with approximate electron-hole symmetry at small rotation angles. These crossings are protected by the emergent sy…
Flat bands and chiral optical response of moiré insulators
H. Ochoa, A. Asenjo-Garcia
We present a low-energy model describing the reconstruction of the electronic spectrum in twisted bilayers of honeycomb crystals with broken sublattice symmetry. The resulting moir…
Tunable strain soliton networks confine electrons in Van der Waals materials
Drew Edelberg, Hemant Kumar, Vivek Shenoy +2
Sliding and twisting van der Waals layers with respect to each other gives rise to moiré structures with emergent electronic properties. Electrons in these moiré structures feel we…
Colloquium: Spintronics in graphene and other two-dimensional materials
A. Avsar, H. Ochoa, F. Guinea +3
After the first unequivocal demonstration of spin transport in graphene (Tombros et al., 2007), surprisingly at room temperature, it was quickly realized that this novel material w…
Moiré-pattern fluctuations and electron-phason coupling in twisted bilayer graphene
Héctor Ochoa
In twisted bilayer graphene, long-wavelength lattice fluctuations on the scale of the moiré period are dominated by phason modes, i.e., acoustic branches of the incommensurate latt…
Hydrodynamics of three-dimensional skyrmions in frustrated magnets
Ricardo Zarzuela, Héctor Ochoa, Yaroslav Tserkovnyak
We study the nucleation and collective dynamics of Shankar skyrmions [R. Shankar, Journal de Physique 38, 1405 (1977)] in the class of frustrated magnetic systems described by an S…
Dynamic imaging of an antiferromagnetic domain wall via quantum-impurity relaxometry
B. Flebus, H. Ochoa, P. Upadhyaya +1
While spin textures in materials exhibiting zero net magnetization, such as antiferromagnetic domain walls (DWs), have attracted much interest lately due to their robustness agains…
Colloquium: Quantum skyrmionics
Hector Ochoa, Yaroslav Tserkovnyak
Skyrmions are topological solitons that emerge in many physical contexts. In magnetism, they appear as textures of the spin-density field stabilized by different competing interact…
Spin hydrodynamics in amorphous magnets
Hector Ochoa, Ricardo Zarzuela, Yaroslav Tserkovnyak
Spin superfluidity, i.e., coherent spin transport mediated by topologically stable textures, is limited by parasitic anisotropies rooted in relativistic interactions and spatial in…
Generalized Boundary Conditions for Spin Transfer
Yaroslav Tserkovnyak, Hector Ochoa
We develop a comprehensive description of static and dynamic spin-transfer torque at interfaces between a normal metal and a magnetic material. Specific examples of the latter incl…
Gyrotropic elastic response of skyrmion crystals to current-induced tensions
Hector Ochoa, Se Kwon Kim, Oleg Tchernyshyov +1
We theoretically study the dynamics of skyrmion crystals in electrically-insulating chiral magnets subjected to current-induced spin torques by adjacent metallic layers. We develop…
Chiral charge pumping in graphene deposited on a magnetic insulator
Michael Evelt, Hector Ochoa, Oleksandr Dzyapko +7
We demonstrate that a sizable chiral charge pumping can be achieved at room temperature in graphene/Yttrium Iron Garnet (YIG) bilayer systems. The effect, which cannot be attribute…
Emergent gauge fields from curvature in single layers of transition-metal dichalcogenides
Hector Ochoa, Ricardo Zarzuela, Yaroslav Tserkovnyak
We analyze the electron dynamics in corrugated layers of transition-metal dichalcogenides. Due to the strong spin-orbit coupling, the intrinsic (Gaussian) curvature leads to an eme…
Topological spin-transfer drag driven by skyrmion diffusion
Hector Ochoa, Se Kwon Kim, Yaroslav Tserkovnyak
We study the spin-transfer drag mediated by the Brownian motion of skyrmions. The essential idea is illustrated in a two-terminal geometry, in which a thin film of a magnetic insul…
A Realization of the Haldane-Kane-Mele Model in a System of Localized Spins
Se Kwon Kim, Héctor Ochoa, Ricardo Zarzuela +1
We theoretically study a spin Hamiltonian for spin-orbit-coupled ferromagnets on the honeycomb lattice. We find that the effective Hamiltonian for magnons, a quanta of spin-wave ex…
Extrinsic Spin Hall Effect from Anisotropic Rashba Spin-Orbit Coupling in Graphene
H-Y. Yang, Chunli Huang, Hector Ochoa +1
We study the effect of anisotropy of the Rashba coupling on the extrinsic spin Hall effect due to spin-orbit active adatoms on graphene. In addition to the intrinsic spin-orbit cou…
Exchange and collective behavior of magnetic impurities in a disordered helical metal
Hector Ochoa
We study the exchange interaction and the subsequent collective behavior of magnetic impurities embedded in a disordered two-dimensional (2D) helical metal. The exchange coupling f…
Spin-valley relaxation and quantum transport regimes in two-dimensional transition metal dichalcogenides
Hector Ochoa, Francesca Finocchiaro, Francisco Guinea +1
Quantum transport and spintronics regimes are studied in p- and n-doped atomic layers of hexagonal transition metal dichalcogenides (TMDCs), subject to the interplay between the va…
Interactions and magnetic moments near vacancies and resonant impurities in graphene
P. Haase, S. Fuchs, T. Pruschke +2
The effect of electronic interactions in graphene with vacancies or resonant scatterers is investigated. We apply dynamical mean-field theory in combination with quantum Monte Carl…