Chiral domain walls of Mn3Sn and their memory

Abstract

Magnetic domain walls are topological solitons whose internal structure is set by competing energies which sculpt them. In common ferromagnets, domain walls are known to be of either Bloch or Néel types. Little is established in the case of Mn 3 Sn, a triangular antiferromagnet with a large room-temperature anomalous Hall effect, where domain nucleation is triggered by a well-defined threshold magnetic field. Here, we show that the domain walls of this system generate an additional contribution to the Hall conductivity tensor and a transverse magnetization. The former is an electric field lying in the same plane with the magnetic field and electric current and therefore a planar Hall effect. We demonstrate that in-plane rotation of spins inside the domain wall would explain both observations and the clockwise or anticlockwise chirality of the walls depends on the history of the field orientation and can be controlled.

Anomalous and topological Hall effects in epitaxial thin films of the noncollinear antiferromagnet Mn3Sn

“…This may indicate that the transition from the inverse triangular to glassy FM state during cooling is not fully reversible until close to the Néel temperature (TN = 420 K [4]), for example due to pinning of the magnetic structure at AF domain walls discussed below. These results are in agreement with Li et al [34], who measure a symmetric planar Hall effect in Mn3Sn single crystals, attributed to domain walls whose internal moment configuration is maintained during forward and reverse field sweeps (but whose sense of rotation is inverted). They also observe a dependence of the planar Hall effect polarity on applied field history.…”

Giant anomalous Hall effect in quasi-two-dimensional layered antiferromagnet Co1/3NbS2

“…Only recently has it been appreciated that the AHE can arise more generally in systems with broken time-reversal symmetry (TRS). Based on this notion, the occurrence of AHE in antiferromagnets (AFMs) with vanishing magnetization has been predicted theoretically [2][3][4][5] and confirmed experimentally on materials such as Mn 3 Sn [6][7][8], Mn 3 Ge [9,10], Mn 3 Ga [11], and Mn 5 Si 3 [12][13][14]. In all these systems, the AHE originates from the nonvanishing integral of the Berry curvature n (q) over the occupied states, with the transverse conductivity given by σ xy = e 2 h BZ…”

Tailoring Dzyaloshinskii-Moriya interaction in a transition metal dichalcogenide by dual-intercalation

“…Meanwhile, this increased density of skyrmion could facilitate the promising next generation lowenergy and high-density storage spintronic devices based on skyrmion systems and the manipulation of dynamics of skyrmions through gate tunable DMI. Recently, the chiral domain wall with Z6 vortex was suggested to account for the observation of THE in Mn3Sn[34,35]. Analogically, the chiral domain wall with Z6 (Z2×Z3) vortex in Theoretical analysis and First-principles calculations suggest that the sizable DMI dominantly comes from the intercalated Fe atoms, playing a key role in magnetic orders and the formation of the chiral supercells with broken SIS.…”