Magnonic analog of the Edelstein effect in antiferromagnetic insulators

Abstract

We investigate the nonequilibrium spin polarization due to a temperature gradient in antiferromagnetic insulators, which is the magnonic analogue of the inverse spin-galvanic effect of electrons. We derive a linear response theory of a temperature-gradient-induced spin polarization for collinear and noncollinear antiferromagnets, which comprises both extrinsic and intrinsic contributions. We apply our theory to several noncentrosymmetric antiferromagnetic insulators, i.e., to a one-dimensional antiferromagnetic spin chain, a single layer of kagome noncollinear antiferromagnet, e.g., KFe3(OH)6(SO4)2, and a noncollinear breathing pyrochlore antiferromagnet, e.g., LiGaCr4O8.

Spirals and skyrmions in antiferromagnetic triangular lattices

“…To identify the phase transitions, we calculate the specific heat, the topological susceptibility, and the total topological charge according to Eqs. ( 9), (10), and (6), respectively. Some of the curves used for identifying phase transitions are shown in Fig.…”

“…Concepts of topology have influenced the development of condensed matter physics, e.g., as can be seen in realizations of magnetic skyrmions in ferromagnets [3][4][5]. Realizations of skyrmions in collinear antiferromagnets (AFMs) are also being explored [6][7][8][9][10]. Studies of three-sublattice systems generalize above ideas to noncollinear antiferromagnets and demonstrate possibilities for realizations of various skyrmion phases [11][12][13][14][15].…”

Magnon spin transport around the compensation magnetic field in easy-plane antiferromagnetic insulators

“…Interestingly, the spatial motion of the magnons in AFIs, similar to the mobile electrons in metallic systems, can be correlated with their spin polarization, for example, in noncentrosymmetric systems via the Dzyaloshinskii-Moriya interaction (DMI), which provides the possibility to discovery electron-like spin-orbit phenomena. Theoretical studies predicted magnon spin Nernst effect [24,25] and magnonic Edelstein effect [26,27] driven by DMI. Recently, the dipole-dipole interaction (DDI), which was usually ignored in antiferromagnets, was shown to be able to manifest itself as an effective spinorbit coupling (SOC) [28,29] between magnon states in uniaxial easy-axis AFIs.…”

Spin superfluidity in noncollinear antiferromagnets

“…The noncollinear conducting magnets can exhibit a multitude of phenomena associated with topology of electronic bands [21], e.g., Mn 3 X (X = Ge, Sn, Ga, Ir, Rh, or Pt) magnets exhibit the anomalous [22] and spin [23] Hall responses. Various magnon-mediated responses relying on magnon spin-momentum locking, topology of magnonic bands, and coupling to phonons have been studied theoretically, promising observation of spin-related phenomena in insulating antiferromagnets [24][25][26][27][28][29][30][31][32].…”