Strong anisotropic Hall effect in single-crystalline CeMn2Ge2 with helical spin order

The topological Hall effect (THE) is an emergent magnetotransport phenomena in noncollinear itinerant magnets, and has been extensively studied in magnetic materials hosting skyrmion lattices and geometrically frustrated lattices. To explore THE in materials with new nontrivial spin textures, we investigate the anisotropic Hall effect in a longitudinal conical-ordered magnet CeMn2Ge2 crystallized in ThCr2Si2-type structure, which has a spiral magnetic propagation vector along the c axis and a helical component in the ab plane. Magnetic susceptibility reveals it undergoes two magnetic transitions at similar to 394 and similar to 318 K; the latter corresponds to the antiferromagnetic to conical spin order transition in the magnetic Mn lattices. For applied field (mu H-0) along the c axis, CeMn2Ge2 exhibits conventional anomalous Hall effect with large intrinsic Hall conductivity sigma(int)(xy) similar to 276 Omega(-1) cm(-1) but no THE responses. A large THE is realized as mu H-0 is oriented within the ab plane xy due to a field-induced noncoplanar spin texture with scalar spin chirality. Moreover, room temperature (RT) angle-dependent Hall effect measurements reveal the THE emerges when the field is applied nonparallel to the c axis and it reaches maximal value for mu H-0 when it is tilted close to the ab plane with a canting angle of similar to 15 degrees, at which large topological Hall conductivity of similar to 43 Omega(-1) cm(-1) is detected. Our results demonstrate a RT anisotropic THE and its tunability by the application of a tilted magnetic field in conical-ordered magnets, making a step forward for designing spintronic devices based on THE.