Giant anomalous Hall effect from spin-chirality scattering in a chiral magnet

Abstract

The electrical Hall effect can be significantly enhanced through the interplay of the conduction electrons with magnetism, which is known as the anomalous Hall effect (AHE). Whereas the mechanism related to band topology has been intensively studied towards energy efficient electronics, those related to electron scattering have received limited attention. Here we report the observation of giant AHE of electron-scattering origin in a chiral magnet MnGe thin film. The Hall conductivity and Hall angle, respectively, reach $$40,000$$ 40 , 000 Ω−1 cm−1 and $$18$$ 18 % in the ferromagnetic region, exceeding the conventional limits of AHE of intrinsic and extrinsic origins, respectively. A possible origin of the large AHE is attributed to a new type of skew-scattering via thermally excited spin-clusters with scalar spin chirality, which is corroborated by the temperature–magnetic-field profile of the AHE being sensitive to the film-thickness or magneto-crystalline anisotropy. Our results may open up a new platform to explore giant AHE responses in various systems, including frustrated magnets and thin-film heterostructures.

Colossal topological Hall effect at the transition between isolated and lattice-phase interfacial skyrmions

“…The spin chirality contribution to the T HE originates from a non-zero scalar triple product [S i • (S j × S k )], where S i , S j , and S k form a cluster consisting of three fluctuating spins. Such clusters can generate Hall signals via an unconventional skew-scattering mechanism which can greatly exceed the contribution from a stable skyrmion configuration [15,16,17,26]. The size of these clusters can be as small as several atomic spacings, which is much smaller than the skyrmion radius determined by the macroscopic magnetic interaction parameters in our films.…”

Unconventional Anomalous Hall Effect in the Canted Antiferromagnetic Half‐Heusler Compound DyPtBi

“…The AHA of 30% reported here at B = 3 T is significant compared to, for example, the typical magnetic WSM Co 3 Sn 2 S 2 with AHA = 20%, [ 2d ] Co 2 MnAl with AHA = 22.5%, [ 2e ] and MnGe thin film with Giant AHE, AHA = 18%. [ 26 ] This means that this compound could exhibit quantum AHE in the 2D limit state. Combining the canted type II spin texture and axis dependence, we can deduce that the AHE can be easily controlled by an external magnetic field.…”

Above-ordering-temperature large anomalous Hall effect in a triangular-lattice magnetic semiconductor

“…Furthermore, this AHE can emerge even above the magnetic ordering temperature reflecting thermal average of the spin chirality, while the intrinsic AHE based on the Berry phase disappears above the ordering temperature. Actually, AHE above the magnetic ordering temperature has been observed in a metal hosting skyrmions ( 21 , 22 ), which has been ascribed to the skew scattering by fluctuating but locally correlated spins originally forming the skyrmion lattice below the ordering temperature. Moreover, large AHE ascribed to the spin cluster scattering has been observed in a Kagome metal even without magnetic ordering ( 23 ).…”