Kondo physics in antiferromagnetic Weyl semimetal Mn _{3+ x} Sn _{1− x} films

Abstract

Topology and strong electron correlations are crucial ingredients in emerging quantum materials, yet their intersection in experimental systems has been relatively limited to date. Strongly correlated Weyl semimetals, particularly when magnetism is incorporated, offer a unique and fertile platform to explore emergent phenomena in novel topological matter and topological spintronics. The antiferromagnetic Weyl semimetal Mn3Sn exhibits many exotic physical properties such as a large spontaneous Hall effect and has recently attracted intense interest. In this work, we report synthesis of epitaxial Mn3+xSn1−x films with greatly extended compositional range in comparison with that of bulk samples. As Sn atoms are replaced by magnetic Mn atoms, the Kondo effect, which is a celebrated example of strong correlations, emerges, develops coherence, and induces a hybridization energy gap. The magnetic doping and gap opening lead to rich extraordinary properties, as exemplified by the prominent DC Hall effects and resonance-enhanced terahertz Faraday rotation.

Chiral-anomaly-driven magnetotransport in the correlated Weyl magnet Mn$_3$Sn

“…Such behavior is characteristic of the Kondo effect and is absent for the two lower doping levels x = 0.053 and x = 0.070. Our finding is consistent with previous reports that the Kondo effect emerges with substantial Mn doping in single crystals and thin-film samples of Mn 3 Sn [36,37].…”

“…The macroscopic TRS breaking engenders the Weyl nodes and the associated strongly enhanced Berry curvature, leading to surprisingly large anomalous transverse transport and magnetooptical effects comparable to those of conventional ferromagnets, despite the negligible net magnetization of the AFM order [7,22,34,35]. The magnetic Weyl fermions in Mn 3 Sn are accompanied by strong correlations, as evident from significant bandwidth renormalization and the Kondo effect induced by substantial Mn doping at the Sn sites [36,37]. Thus, a systematic study of the chiral-anomaly-driven magnetotransport in Mn 3 Sn may provide unprecedented insights into intrinsic behavior of the correlated magnetic WSM state.…”

Quantum Sensing and Imaging of Spin–Orbit‐Torque‐Driven Spin Dynamics in the Non‐Collinear Antiferromagnet Mn3Sn

“…[1][2][3] Noncollinear antiferromagnets based on the Mn3X composition (X = Sn, Ge, Ga, Ir, Pt, Rh) are particularly relevant in this context and have recently been the subject of immense research. [4][5][6][7][8][9][10][11][12][13] Due to the spontaneous time-reversal symmetry breaking, noncollinear magnetic order, and topologically nontrivial band structure near the Fermi surface, a range of counterintuitive and exotic phenomena have been observed in this emergent class of quantum materials. Examples include large anomalous Hall and anomalous Nernst effects, [8][9][10]12,13] chiral anomalies, [4] magnetic spin Hall effects, [14,15] and the promotion of long-range supercurrents, [16] offering an attractive platform to explore the interplay between topology, electron correlations, and magnetism.…”

Giant intrinsic anomalous terahertz Faraday rotation in the magnetic Weyl semimetal Co$_2$MnGa at room temperature

“…2F, we show the normalized Faraday rotation by thickness at room temperature, Co 2 MnGa has the largest value of 3 mrad/nm to our best knowledge. It is 30 times larger than the value in the Weyl antiferromagnet candidate Mn 3 Sn 46,47 . Even if we compare it with other reported values at low temperature, 3 mrad/nm is larger than any material report and is similar to another magnetic Weyl semimetal Co 3 Sn 2 S 2 48 .…”