Magnetic domain wall bimerons (DWBMs) offer a platform for current-driven transport in patterned magnetic stripes. However, soliton-soliton interactions and defect pinning complicate their reliable motion. We demonstrate that periodic defect arrays stabilize multi-DWBM transport and give rise to a distinctive collective state, the magnetic worm. A single DWBM travels at constant speed, with defects reducing this speed while preserving an approximately linear velocity-current relation. For two DWBMs, the center of mass advances nearly uniformly while their separation exhibits bounded oscillations whose frequency increases and amplitude decreases with current. For larger trains, the oscillations lose synchrony, producing segmented, wormlike motion. This pattern emulates wormlike locomotion through retrograde peristaltic waves, effectively modulating surface friction. These findings open pathways toward current-controlled nano-oscillators, phase-coded racetrack logic, and on-chip defect sensing in patterned racetrack devices.

We introduce a minimal model of a two-dimensional lattice that, upon spontaneous symmetry breaking, simultaneously develops altermagnetic order, a finite electric polarization, and a spin-polarized transport response, all of which are controlled by an external electric field. By coupling a dimerized altermagnet to an external electric field, we show that the three order parameters are not merely compatible but dynamically entangled, so that switching one (for instance, reversing the polarization with an electric field) necessarily reconfigures the other two. We show that this model offers a clear physical blueprint for designing next-generation spintronic logic and pure spin current memdevices that merge the ultrafast, stray-field-free advantages of compensated magnets with the low-power switching architectures of ferroelectrics.

Spin currents can be generated through various mechanisms, including the piezospintronic effect, which arises when strain or lattice distortions induce a change in the dipolar spin moment, causing a pure spin current without necessarily being accompanied by net charge transport. This opens new possibilities for low-power information processing and novel device architectures. In this work, we propose a novel effect, the spintronic-magneto-impedictive effect, as the theoretical basis for a pure spin-current memory-like device based on antiferromagnetic components. We focus on materials that can be modeled by the so-called spin-Rice-Mele Hamiltonian, incorporating a magnetic field gradient that explicitly breaks inversion symmetry. Our results shed light on how spin currents are generated and controlled, providing new insights into the potential of these materials for next-generation spintronic technologies.

We propose a spintronic memcapacitance effect based upon altermagnetic multiferroic materials. We identify the rare-earth vanadates RVO_3 as a concrete platform, with all key parameters tied to measured properties. Under an oscillating electric field, the resulting charge and spin currents trace pinched hysteresis loops that close tangentially at zero field – the hallmark of memcapacitive, type-2 memdevice behavior – with charge current densities exceeding, by a factor of about 3.6, the lowest deterministic switching current density reported for optimized spin-transfer-torque magnetic tunnel junctions. We model the system theoretically as a dimerized two-orbital d-wave altermagnetic lattice via a Su–Schrieffer–Heeger-type bond modulation, in the spirit of the spin-dependent Rice–Mele model, thereby coupling the altermagnetic order to field-switchable charge and spin polarizations. The associated polarization loops close tangentially at zero field and yield a sign-changing, history-dependent “butterfly” differential capacitance, identifying the device as a genuine memcapacitor. Both responses are protected by the same inversion symmetry, so charge and spin channels switch simultaneously with no separate control needed. These results establish altermagnetic multiferroics, realized concretely in RVO_3, as an efficient, non-volatile platform for combined electric and spintronic memory.

Piezoelectric memristors represent a convergent frontier in advanced materials science, merging the mechanical-to-electrical transduction properties of piezoelectric materials with the nonlinear, history-dependent resistance behavior characteristic of memristive devices. By combining the inherent ability of piezoelectric materials to convert mechanical deformation into electrical signals with the programmable, nonvolatile resistance switching of memristors, these hybrid components transcend the limitations of conventional single-function devices, offering an integrated platform for concurrent sensing, actuation, and information storage. This convergence is particularly consequential for the field of neuromorphic engineering, where replicating the dynamic plasticity of biological synapses requires components that can detect, respond to, and durably encode incoming signals-a set of demands that piezoelectric memristors are uniquely positioned to fulfill within a single material stack. Beyond cognitive computing architectures, these devices introduce transformative possibilities for energy-autonomous systems, leveraging piezoelectricity to scavenge kinetic energy from environmental sources, such as structural vibrations, human motion, or pressure fluctuations, thereby powering resistive switching operations in the complete absence of conventional energy supplies. In this work, a minimal theoretical framework for an intrinsic piezoelectric memristor is introduced, grounded in the physics of a dimerized one-dimensional chain. The model is reduced to an effective Rice-Mele Hamiltonian, a standard viewpoint for ferroelectric research, which provides both analytical tractability and physical transparency. The numerical simulations are consistent with those reported for polarization-switching features and introduce new dynamical timescales. The stability of the memristive response is also of great significance for neuromorphic and reservoir computing applications.

We investigate spin-wave propagation in magnetic insulators in the presence of lattice dislocations. Within a continuum magnetoelastic framework, we show that the strain fields generated by dislocations induce equilibrium magnetic textures. The morphology of these textures depends sensitively on the dislocation type and acts as a localized scattering potential for spin-wave excitations. As a result, the scattering response exhibits pronounced asymmetries and interference effects governed by the magnetoelastic coupling and the dislocation type. By combining numerical simulations with analytical scattering theory, we compute differential cross sections and frequency-dependent transmission coefficients. Furthermore, analysis of the effective potential landscape reveals that the defect forms a barrier that modulates spin-wave transport and, crucially, breaks the intrinsic reflectionless nature of magnetic domain walls. Our findings identify lattice dislocations as tunable scattering centers, opening new avenues for defect engineering in magnonic devices.

Topologically spin configurations, such as skyrmions and bimerons, offer a compelling alternative to conventional magnetic domains, potentially enabling high-density, low-power spintronic devices. These textures, characterized by their swirling spin textures and nontrivial topological charges, can be strongly influenced by imperfections in the underlying crystal lattice. In particular, dislocations which are commonly presents in real materials, may alter the magnetic energy landscape and impact the stability or dynamics of spin textures. Motivated by this, we study how a screw dislocation influences skyrmion motion. We show that the dislocation acts as a shallow, radially symmetric trap that confines the skyrmion at a finite distance from the defect core. Using both classical and semiclassical approaches, we characterize the resulting bound states and obtain discrete quantized energy levels with half-integer orbital angular momentum. Finally, we outline a device concept in which an array of dislocations guides current-driven skyrmion motion and enables electrical detection via a topological Hall response. These results suggest that dislocations can be used as functional elements for controlling topological spin textures in spintronic devices.

We show that a traveling modulation of the polarization-gradient stiffness in a ferroelectric material induces an effective flow in its collective polarization dynamics. Within a controlled local approximation, small polarization fluctuations, or ferrons, obey a massive Klein-Gordon equation with flow. Unlike conventional analogue-gravity platforms, the effective flow originates from the modulation of the material parameters rather than from the physical transport of the medium. This mechanism enables mobile analogue horizons separating sub-ferronic and super-ferronic regions, the latter supporting negative-norm antiferron modes. Their coupling to positive-norm ferrons gives rise to superradiant-like amplification, while the effective mass gap can be tuned independently through an external electric field. Ferroelectric systems therefore provide a novel and experimentally controllable platform for analogue gravity with massive scalar excitations.

The interplay between the geometry of the magnetic body and the topology of magnetization patterns opens new ways for controlling the nucleation and dynamics of three-dimensional chiral spin structures. Here, we analyze the stability of a Bloch point (BP) chain within a magnetic nanotorus and analyze the magnon spectrum of the system. Our results evidence that toroidal nanorings with a large cross-section area allow the nucleation of metastable states comprising a geometry-dependent BP pairs. The nucleation and stabilization of these BP pairs are a direct consequence of the role the geometry plays in the topology of three-dimensional (3D) topological textures. Indeed, we show that both the variable Gaussian curvature along its surface and the torus genus ensure the nucleation of stable swirling states, including vortex and topological 3D configurations. These chiral states can be identified by the suppression of frequencies within the spin-wave spectra and the ensuing topological phase transitions from BP chains to the vortex state.

This paper presents a novel approach for generating and controlling spin currents in an antiferromagnetic twisted honeycomb bilayer in response to elastic deformation. Using a continuum model based on the Bistritzer–MacDonald model that captures the physics of low-energy moiré bands, we calculate the spin-current response in the Berry-phase formalism. The resulting moiré superlattice potential modulates the electronic band structure, leading to emergent topological phases and novel transport properties such as quantized piezo responses both for spin and charge transport. This approach allows us to tune the system across different topological regimes and to explore the piezo-spintronic responses as a function of the band topology. When inversion symmetry is broken either by a sublattice potential V, alignment with an hBN substrate, uniaxial strain, or structural asymmetry present in the moiré superlattice, the system acquires a finite Berry curvature that is opposite in the K and $${K}^{{\prime} }$$ valleys (protected by valley time reversal symmetry). In contrast, for strain, the valley-contrasting nature of the pseudo-gauge field ensures that the quantized response is robust and proportional to the sum of the valley Chern numbers. These notable physical properties make these systems promising candidates for groundbreaking spintronic and valleytronic devices.

Topologically secure spin configurations, such as skyrmions and bimerons, offer a compelling alternative to conventional magnetic domains, potentially enabling high-density, low-power spintronic devices. These pseudo-particles, characterized by their swirling spin textures and nontrivial topological charges, are prevalent and notably influence their electronic, magnetic, and mechanical traits. This paper provides an in-depth overview of the interaction between a screw dislocation within a distorted magnetic lattice, exploring possible coupling mechanisms and establishing a promising link between two disparate topics in materials science: topological magnetism and topological elasticity. We first provide a classical analysis of skyrmion motion that reveals the dislocations as shallow traps on the magnetic texture. Afterwards, we provide an analysis of the quantized motion of the skyrmion and identify its quantum states. We conclude by illustrating how the ideas in our paper can be implemented in simple yet compelling devices based on the shallow traps from an array of dislocations acting as frets in a race-track, controlling the motion with a low current activation mechanism.

The geometry of a magnetic body is fundamental when considering applications based on domain wall (DW) propagation in nanometric systems. In this framework, helical systems allow the exploration of new and interesting phenomena. Through micromagnetic simulations and analytical calculations, we study the propagation of N & eacute;el DWs under the action of a spin-polarized current hosted in a helix-shaped nanowire (NW) with constant curvature and torsion and an uniaxial anisotropy pointing locally perpendicularly to the NW. Our results show that for a N & eacute;el DW propagating in a twisted NW, the effect of torsion (curvature) is equivalent to curvature (torsion) effects on the propagation of a transverse DW in an equivalent system.

We introduce the concept of antiferron modes in ferroelectric materials as dynamically stabilized collective excitations over inverted polarization states that decrease the system energy. While ferrons represent quantized oscillations around the stable polarization minimum, antiferrons require dynamic stabilization via high-frequency driving. Using a generalized Landau-Ginzburg-Devonshire framework, we derive the effective curvature corrections from external driving, demonstrate the conditions for stabilizing metastable wells, and present the quantized Hamiltonian. Antiferrons could be a promising candidate for developing electrical sensing devices, offering tunable, dynamically controllable excitations with high sensitivity to external electric fields.

We demonstrate that domain walls built from bimeron chains (bc-DW) in two-dimensional systems constitute a spontaneously assembled medium that holds magnonic excitations along its direction. We prove that such magnons are topological, leading to protected edge states. We also verify the stability of the domain walls and its edge modes' resilience against disorder. Analytical calculations and micromagnetic simulations support our findings. The robustness of these edge modes holds promise for potential applications in the design of nanoscale magnonic devices for information storage and transport.

This paper presents a novel approach for generating and controlling spin currents in an antiferromagnetic twisted honeycomb bilayer in response to an elastic deformation. Utilizing a continuum model, closely based upon the seminal Bistritzer-MacDonald model, that captures the essential physics of low-energy moiré bands, we calculate the spin current response to the deformation in terms of the familiar Berry phase formalism. The resulting moiré superlattice potential modulates the electronic band structure, leading to emergent topological phases and novel transport properties such as quantized piezo responses both for spin and charge transport. This approach allows us to tune the system across different topological regimes and to explore the piezo-spintronic responses as a function of the band topology. When inversion symmetry is broken either by a sublattice potential $V$, alignment with an hBN substrate, uniaxial strain, or structural asymmetry present in the moiré superlattice, the system acquires a finite Berry curvature that is opposite in the $K$ and $K'$ valleys (protected by valley time reversal symmetry). In contrast, for strain, the valley-contrasting nature of the pseudo-gauge field ensures that the quantized response is robust and proportional to the sum of the valley Chern numbers. These notable physical properties make these systems promising candidates for groundbreaking spintronic and valleytronic devices.

Topological magnetic textures confined to two-dimensional (2D) non-orientable manifolds exhibit behaviors absent in planar systems. We investigate bimerons on Möbius surfaces and show that the lack of global orientation alters conservation laws, yielding geometry-dependent topology and dynamics. Micromagnetic simulations reveal that the helical twist and non-orientable geometry reshape the effective topological charge and stabilize chiral configurations imposed by the surface. Under spin-polarized currents, bimerons display unconventional transport: the transverse response is locally reversed or globally suppressed due to charge inversion along the manifold. Moreover, we establish an Aharonov-Bohm effect associated with the magnonic modes of the texture; in particular, the translational Goldstone mode implies that a bimeron on a Möbius strip should exhibit path-dependent quantum interference. These results identify a geometry-driven regime of magnetization dynamics and provide a route to curvature-engineered spintronic functionalities.

Magnetic bimerons offer a compelling alternative to skyrmions in next-generation spintronic devices. These topologically equivalent structures arise in chiral magnetic systems with in-plane magnetization driven by anisotropies or external magnetic fields. However, their use in current-driven systems is hindered by the bimeron Hall effect, which causes transverse motion and edge annihilation. Addressing these limitations, we uncover a novel mechanism for stabilizing bimeron propagation under current-driven conditions. We demonstrate that bimerons can propagate along thin ferromagnetic strips without annihilation when the easy-axis anisotropy and electric current are orthogonal. Our findings show a 6-fold velocity increase near strip edges due to boundary interactions. Furthermore, bimerons remain stable in curved geometries, allowing robust propagation in complex racetracks. This behavior also extends to bimeron chains, which propagate in parallel, forming stable and efficient configurations for information transport. These findings open new pathways toward practical and efficient bimeron-based racetrack memory technologies.

We analyze the collective excitations of a magnetoelectric multiferroic material and show that the coupling between magnetization and polarization fluctuations gives rise to hybrid modes-electromagnons-resulting from the mixing of magnons (oscillations of the magnetization field) and polarization waves (ferrons). We characterize their main properties and discuss their potential applications in multiferroic-based technologies. Additionally, we provide a phenomenological framework for these systems, which will be invaluable for describing the dynamics of the multiferromagnetic state.

Spin fluctuations in two-dimensional ferromagnets in the presence of crystalline lattice dislocations are investigated. We show the existence of topologically protected nonpropagative modes that localize at dislocations. These in-gap states, termed magnonic dislocation modes, are characterized by the Z2 topological invariant that derives from broken parity symmetry induced by sublattice magnetic anisotropy. We uncover that bulk topology existing in the perfect crystal is robust under the influence of lattice defects, which is monitored by the real-space Bott index. It is also revealed that the topology of magnonic dislocation modes remains unaffected when bulk topology becomes trivial and is remarkably resilient against magnetic disorder. Our findings point to the intriguing relationship between topological lattice defects and the spectrum of topological spin excitations.

This work analyzes the behavior of the interface between a ferromagnetic material and an alter-magnet. We use a well-established line of arguments based on electronic mean-field calculations to show that new surface phenomena that lead to altermagnetic materials induce an exchange bias effect on the nearby ferromagnet. We reveal the physical mechanisms behind this phenomenon that lead to quantitative control over its strength. Interestingly, we predict exotic electric-field-induced phenomena. This is an analogy to the relationship between exchange bias and the injection of spin currents in spin-transfer-dominated scenarios, which has been reported earlier in the traditional antiferromagnetic/ferromagnetic junction.