We show theoretically that both intrinsic spin Hall effect (SHE) and orbital (OHE) can arise in centrosymmetric systems through momentum-space texture, which is ubiquitous even unlike texture. OHE occurs without spin-orbit coupling (SOC) converted into SHE SOC. The resulting conductivity large (comparable to of Pt) but depends on the SOC strength a nonmonotonic way. This mechanism stable against quenching. work suggests path for an ongoing search materials with stronger SHE. It also calls...

A recent paper [Go $\textit{et al}$., Phys. Rev. Lett. $\textbf{121}$, 086602 (2018)] proposed that the intrinsic orbital Hall effect (OHE) can emerge from momentum-space texture in centrosymmetric materials. In searching for real materials with strong OHE, we investigate OHE metals small spin-orbit coupling (SOC) face-centered cubic and body-centered structures (Li, Al, V, Cr, Mn, Ni, Cu). We find conductivities (OHCs) these are gigantic $\sim 10^3-10^4\...

Current-induced spin-orbit torques (SOTs) allow for the efficient electrical manipulation of magnetism in spintronic devices. Engineering SOT efficiency is a key goal that pursued by maximizing active interfacial spin accumulation or modulating nonequilibrium density builds up through Hall and inverse galvanic effects. Regardless origin, fundamental requirement generation current-induced net accumulation. We report on large enhancement thulium iron garnet (TmIG)/Pt capping with...

We propose a mechanism of torque generation by injection an orbital current, which we call $\textit{orbital torque}$. In magnetic bilayer consisting nonmagnet (NM) and ferromagnet (FM), consider situation where the spin-orbit coupling (SOC) is present only in FM. Although SOC absent NM, Hall effect can arise NM. When resulting current injected to FM, FM converts angular momentum into spin, exerts magnetization Remarkably, even for small strength comparable that $3d$ FMs, be spin induced NM...

The orbital Hall effect describes the generation of current flowing in a perpendicular direction to an external electric field, analogous spin effect. As carries angular momentum as does, injection into ferromagnet can result torque on magnetization, which provides way detect With this motivation, we examine current-induced spin-orbit torques various ferromagnet/heavy metal bilayers by theory and experiment. Analysis magnetic reveals presence contribution from heavy metal, competes with In...

Spin Hall effect, an electric generation of spin current, allows for efficient control magnetization. Recent theory revealed that orbital effect creates which can be much larger than Hall-induced current. However, current cannot directly exert a torque on ferromagnet, requiring conversion process from to Here, we report two effective methods the through spin-orbit coupling engineering, us unambiguously demonstrate orbital-current-induced torque, or torque. We find is greatly enhanced by...

We report the observation of magnetoresistance (MR) that could originate from orbital angular momentum (OAM) transport in a permalloy (Py)/oxidized Cu (Cu^{*}) heterostructure: Rashba-Edelstein magnetoresistance. The dependence MR depends on relative angle between induced OAM and magnetization similar fashion as spin Hall Despite absence elements with large spin-orbit coupling, we find sizable ratio, which is contrast to conventional requires heavy elements. Through Py thickness-dependence...

Abstract Modern spintronics relies on the generation of spin currents through spin-orbit coupling. The spin-current has been believed to be triggered by current-induced orbital dynamics, which governs angular momentum transfer from lattice electrons in solids. fundamental role response dynamics suggests importance counterpart currents: currents. However, evidence for its existence elusive. Here, we demonstrate giant and uncover features response. We experimentally theoretically show that...

Abstract The emerging field of orbitronics exploits the electron orbital momentum L . Compared to spin-polarized electrons, may allow transfer magnetic information with considerably higher density over longer distances in more materials. However, direct experimental observation currents, their extended propagation lengths and conversion into charge currents has remained challenging. Here, we optically trigger ultrafast angular-momentum transport Ni|W|SiO 2 thin-film stacks. resulting...

We report and quantify a large orbital-Hall torque generated by Nb Ru, which we identify from strong dependence of torques on the ferromagnets. This is manifested as sign reversal enhancement in damping-like measured (or Ru)/Ni bilayers compared to Ru)/FeCoB bilayers. The long-range nature orbital transport ferromagnet revealed thickness dependences Ni are markedly different regular spin absorption that takes place within few angstroms thus it uniquely distinguishes Hall torque.

While it is often assumed that the orbital response suppressed and short ranged due to strong crystal field potential quenching, we show can be remarkably long in ferromagnets. In a bilayer consisting of nonmagnet ferromagnet, spin injection from interface results accumulation torque which rapidly oscillate decay by dephasing. contrast, even when an external electric applied only on nonmagnet, find substantially long-ranged induced angular momentum go far beyond dephasing length. This...

Motivated by the importance of understanding competing mechanisms to current-induced spin-orbit torque in complex magnets, we develop a unified theory spin-orbital coupled dynamics. The describes angular momentum transfer between different degrees freedom solids, e.g., electron orbital and spin, crystal lattice, magnetic order parameter. Based on continuity equations for spin momenta, derive motion that relate current fluxes torques describing freedom. We then propose classification scheme...

When the inversion symmetry is broken at a surface, spin-orbit interaction gives rise to spin-dependent energy shifts - phenomenon which known as spin Rashba effect. Recently, it has been recognized that an orbital counterpart of effect can be realized surfaces even without spin- orbit coupling. Here, we propose mechanism for based on sp hybridization, ultimately leads electric polarization surface states. As proof principle, show from first principles this chiral textures in...

Efficient electrical generation of torque is desired to develop innovative magnetic nanodevices. The can be generated by charge spin conversion heavy-metal layers through their strong spin-orbit interaction followed the injection converted into adjacent ferromagnetic layers. However heavy atomic elements indispensable for this scheme are often incompatible with device mass production processes. Here we demonstrate efficient without in metal/$\mathrm{Cu}/{\mathrm{Al}}_{2}{\mathrm{O}}_{3}$...

Recent experimental observation of unexpectedly large current-induced spin-orbit torque in surface oxidized Cu on top a ferromagnet suggested possible role the orbital Rashba effect (ORE). With this motivation, we investigate ORE from first principles by considering an oxygen monolayer Cu(111) film. We show that oxidization film leads to gigantic enhancement for states near Fermi surface. The resulting chiral texture momentum space is exceptionally strong, reaching $\sim 0.5\hbar$ magnitude....

Spin torque induced by orbital current has become of great interest, as it allows the use lighter elements in development advanced spin-orbitronic devices. Meanwhile, inverse (IOT) effect, which an creates a charge current, been difficult to detect. This study uses pumped spin-orbital Y${}_{3}$Fe${}_{5}$O${}_{12}$/Pt/CuO${}_{x}$ heterostructures investigate IOT effect. Mixed states propagate Pt/CuO${}_{x}$ interface and create much stronger transverse than that created without CuO${}_{x}$...

Orbital current has emerged over the past years as one of key novel concepts in magnetotransport. Here, we demonstrate that laser pulses can be used to generate large and robust nonrelativistic orbital currents systems where inversion symmetry is broken by Rashba effect. By referring model first principles tools, effect, accompanied crystal field splitting, mediate photocurrents without a need for spin-orbit interaction even metallic systems. We show such are translated into derivative spin...

In the emerging field of orbitronics, orbital Hall effect stands out as one most important transport phenomena angular momentum. Here, authors present a highly efficient and accurate first-principles method to compute by Wannier interpolation point crucial role anomalous position for gauge-covariant description. The work guides ongoing experimental efforts on quantitative measurement currents.

Abstract One of the ultimate goals spintronics is to realize an efficient electrical manipulation spin for high-speed and low-power nanodevices. A core ingredient achieving this goal relativistic interaction between electron’s orbital motion spin, but properties angular momentum itself have remained largely unexplored. However, recent theories experiments uncovered that electrons may acquire nonvanishing when external electric field applied, even without spin–orbit coupling. These findings...

Recent advances in the manipulation of orbital angular momentum (OAM) within paradigm orbitronics presents a promising avenue for design future electronic devices. In this context, recently observed Hall effect (OHE) occupies special place. Here, focusing on both second-order topological and quantum anomalous insulators two-dimensional ferromagnets, we demonstrate that phase transitions present an efficient straightforward way to engineer OHE, where OAM distribution can be controlled by...

The generation of current-induced torques through the spin Hall effect in Pt has been key to development spintronics. In prototypical ferromagnetic-metal/Pt devices, characteristic length torque is known be about 1 nm due short diffusion Pt. Here, we report observation a long-range Ni/Pt bilayers. We demonstrate that when Ni used as ferromagnetic layer, efficiency increases with thickness, even it exceeds 10 nm. also enhanced by increasing providing evidence observed cannot attributed layer....

We show that dynamics of the magnetization in ferromagnets can pump orbital angular momentum, a phenomenon we refer to as pumping. This is reciprocal torque induces by momentum nonequilibrium. The pumping analogous spin established spintronics, but it requires spin-orbit coupling for interact with magnetization. develop formalism describes generation within adiabatic perturbation theory. Based on this, perform first-principles calculations prototypical <a:math...