Switchable chiral transport in charge-ordered kagome metal CsV3Sb5

• Published in: Nature (London) 2022-11, Vol.611 (7936), p.461-466
• Main Authors: Guo, Chunyu, Putzke, Carsten, Konyzheva, Sofia, Huang, Xiangwei, Gutierrez-Amigo, Martin, Errea, Ion, Chen, Dong, Vergniory, Maia G., Felser, Claudia, Fischer, Mark H., Neupert, Titus, Moll, Philip J. W.
• Format: Article
• Language: English
• Subjects: 639/301/119/995; 639/766/119/995; Anisotropy; Broken symmetry; Chiral materials; Chirality; Conductors; Crystals; Electric conductors; Handedness; Humanities and Social Sciences; Magnetic fields; Metals; multidisciplinary; Nonlinear response; Science; Science (multidisciplinary); Second harmonic generation; Symmetry; Temperature; Temperature dependence; Transport properties
• ISSN: 0028-0836; 1476-4687; 1476-4687
• DOI: 10.1038/s41586-022-05127-9

When electric conductors differ from their mirror image, unusual chiral transport coefficients appear that are forbidden in achiral metals, such as a non-linear electric response known as electronic magnetochiral anisotropy (eMChA) 1 – 6 . Although chiral transport signatures are allowed by symmetry in many conductors without a centre of inversion, they reach appreciable levels only in rare cases in which an exceptionally strong chiral coupling to the itinerant electrons is present. So far, observations of chiral transport have been limited to materials in which the atomic positions strongly break mirror symmetries. Here, we report chiral transport in the centrosymmetric layered kagome metal CsV 3 Sb 5 observed via second-harmonic generation under an in-plane magnetic field. The eMChA signal becomes significant only at temperatures below T ′ ≈ 35 K, deep within the charge-ordered state of CsV 3 Sb 5 ( T CDW  ≈ 94 K). This temperature dependence reveals a direct correspondence between electronic chirality, unidirectional charge order 7 and spontaneous time-reversal symmetry breaking due to putative orbital loop currents 8 – 10 . We show that the chirality is set by the out-of-plane field component and that a transition from left- to right-handed transport can be induced by changing the field sign. CsV 3 Sb 5 is the first material in which strong chiral transport can be controlled and switched by small magnetic field changes, in stark contrast to structurally chiral materials, which is a prerequisite for applications in chiral electronics. Change of chirality from left- to right-handed transport in the layered kagome metal CsV 3 Sb 5 can be controlled by small magnetic field changes, a required feature for chiral electronic applications.