Evidence of magnetism-induced topological protection in the axion insulator candidate EuSn ₂ P ₂

Abstract

We unravel the interplay of topological properties and the layered (anti)ferromagnetic ordering in EuSn2P2, using spin and chemical selective electron and X-ray spectroscopies supported by first-principle calculations. We reveal the presence of in-plane long-range ferromagnetic order triggering topological invariants and resulting in the multiple protection of topological Dirac states. We provide clear evidence that layer-dependent spin-momentum locking coexists with ferromagnetism in this material, a cohabitation that promotes EuSn2P2 as a prime candidate axion insulator for topological antiferromagnetic spintronics applications.

Discovery of a Magnetic Dirac System with a Large Intrinsic Nonlinear Hall Effect

“…8−12 Such phases, in the presence of longrange magnetic order, can be modulated with ease, thus offering a methodology to tune the topological protection, hence the charges and spins. 4 Here, we report the experimental discovery of the new system TaCoTe 2 , a topological antiferromagnet with Dirac-like dispersion and SOC-induced gaps at the Fermi level. 13−15 We discover that the combined effect of SOC and magnetic order enables the realization of a large intrinsic nonlinear Hall effect (INHE), which can be tuned by magnetic fields.…”

Engineering magnetic topological insulators in Eu$_5M_2X_6$ Zintls

“…The realization of magnetic TIs has become recently the focus of intense research [10][11][12] with various candidates appearing in the literature [13][14][15][16][17][18][19][20][21]. The most prominent, MnBi 2 Te 4 [13,14], is a layered tetradymite compound with an A-type antiferromagnetic (AFM) order, i.e., with magnetization uniform in-plane but alternating from plane to plane along the stacking direction.…”

“…Of particular interest in the search for magnetic TIs are the Zintls, in which the role of the cation is played by a divalent Eu 2+ and the magnetism comes from the localized, spin-polarized f -orbital manifold. [20] and EuSn 2 P 2 [21].…”

Anisotropic magnetotransport properties coupled with spiral spin modulation in a triangular-lattice magnet EuZnGe

“…Europium-based intermetallics are a group of materials having been investigated for long time and attracting recent interests as a source of various topological spin textures [8][9][10][11] , and exotic transport phenomena including anomalous Hall effect associated with topological band structures [12][13][14][15][16][17] , giant magnetoresistance [18][19][20][21] , coexistence of superconductivity and helimagnetism 22 , three-dimensional quantum Hall effect 23 , and valence transitions 24 .…”