28 research outputs found
Dzyaloshinskii-Moriya Induced Spin-Transfer Torques in Kagome Antiferromagnets
No full textIn recent years antiferromagnets (AFMs) have become very promising for
nanoscale spintronic applications due to their unique properties such as THz
dynamics and absence of stray fields. Manipulating antiferromagnetic textures
is currently, however, limited to very few exceptional material symmetry
classes allowing for staggered torques on the magnetic sublattices. In this
work, we predict for kagome AFMs with broken mirror symmetry a new coupling
mechanism between antiferromagnetic domain walls (DWs) and spin currents,
produced by the relativistic Dzyaloshinskii-Moriya interaction (DMI). We
microscopically derive the DMI's free energy contribution for the kagome AFMs.
Unlike ferromagnets and collinear AFMs, the DMI does not lead to terms linear
in the spatial derivatives but instead renormalizes the spin-wave stiffness and
anisotropy energies. Importantly, we show that the DMI induces a highly
nontrivial twisted DW profile that is controllable via two linearly independent
components of the spin accumulation. This texture manipulation mechanism goes
beyond the concept of staggered torques and implies a higher degree of
tunability for the current-driven DW motion compared to conventional
ferromagnets and collinear AFMs
Voltage-Controlled High-Bandwidth Terahertz Oscillators Based On Antiferromagnets
No full textProducing compact voltage-controlled frequency generators and sensors
operating in the terahertz (THz) regime represents a major technological
challenge. Here, we show that noncollinear antiferromagnets (NCAFM) with kagome
structure host gapless self-oscillations whose frequencies are tunable from 0
Hz to the THz regime via electrically induced spin-orbit torques (SOTs). The
auto-oscillations' initiation, bandwidth, and amplitude are investigated by
deriving an effective theory, which captures the reactive and dissipative SOTs.
We find that the dynamics strongly depends on the ground state's chirality,
with one chirality having gapped excitations, whereas the opposite chirality
provides gapless self-oscillations. Our results reveal that NCAFMs offer unique
THz functional components, which could play a significant role in filling the
THz technology gap.Comment: Finale version accepted by Physical Review Letter
Replication Data for: Spin-Seebeck Signatures of Spin Chirality in Kagome Antiferromagnets
No full textReplication Data for the article "Spin-Seebeck Signatures of Spin Chirality in Kagome Antiferromagnets" submitted in Physical Review B (2025).
The file ‘Fig2.txt’ contains the energy of the three spin-wave bands of the kagome antiferromagnet when it is in the (+)- and (-)-chiral state as a function of the momentum along the x- and y-directions, which is plotted in Figure 2 in the paper.
The file ‘Fig3b.txt’ contains the z-component of the spin current in the (+) chiral state, the z-component of the spin current in the (-)-chiral state, as well as the y-component of the spin current in the (+)-chiral state, normalized by the constant y-component of the spin current in the (-)-chiral state, as a function of the applied magnetic field in the z-direction. The data is plotted in Figure 3b in the paper
