Current-sensitive Hall effect in a chiral-orbital-current state

• Published in: Nature communications 2024-04, Vol.15 (1), p.3579-3579, Article 3579
• Main Authors: Zhang, Yu, Ni, Yifei, Schlottmann, Pedro, Nandkishore, Rahul, DeLong, Lance E., Cao, Gang
• Format: Article
• Language: English
• Subjects: 639/766/119/2794; 639/766/119/995; 639/766/119/997; 639/766/483; Carrier density; Colossal magnetoresistance; Conductivity; Current carriers; Electromagnetism; Hall effect; Humanities and Social Sciences; Magnetic fields; Magnetoresistivity; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-47823-2

Chiral orbital currents (COC) underpin a novel colossal magnetoresistance in ferrimagnetic Mn 3 Si 2 Te 6 . Here we report the Hall effect in the COC state which exhibits the following unprecedented features: (1) A sharp, current-sensitive peak in the magnetic field dependence of the Hall resistivity, and (2) A current-sensitive scaling relation between the Hall conductivity σ xy and the longitudinal conductivity σ xx , namely, σ xy ∝ σ xx α with α reaching up to 5, which is exceptionally large compared to α  ≤ 2 typical of all solids. The novel Hall responses along with a current-sensitive carrier density and a large Hall angle of 15% point to a giant, current-sensitive Hall effect that is unique to the COC state. Here, we show that a magnetic field induced by the fully developed COC combines with the applied magnetic field to exert the greatly enhanced transverse force on charge carriers, which dictates the COC Hall responses. In most materials, the hall conductivity has a scaling to the longitudinal resistance that varies between linear and quadratic. Here, Zhang et al demonstrate a hall conductivity proportional to the fifth power of the longitudinal conductivity in Mn 3 Si 2 Te 6 , which they attribute to enhanced force on charge carriers due to chiral orbital currents.