Fermionic order by disorder in a van der Waals antiferromagnet

• Published in: Scientific reports Vol. 10; no. 1; p. 15311
• Main Authors: Okuma, R., Ueta, D., Kuniyoshi, S., Fujisawa, Y., Smith, B., Hsu, C. H., Inagaki, Y., Si, W., Kawae, T., Lin, H., Chuang, F. C., Masuda, T., Kobayashi, R., Okada, Y.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 17.09.2020; Nature Publishing Group
• Subjects: 639/766; 639/766/119; 639/766/119/997; Crystals; Humanities and Social Sciences; Kinetic energy; Magnetism; multidisciplinary; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-72300-3

CeTe 3 is a unique platform to investigate the itinerant magnetism in a van der Waals (vdW) coupled metal. Despite chemical pressure being a promising route to boost quantum fluctuation in this system, a systematic study on the chemical pressure effect on Ce 3+ (4 f 1 ) states is absent. Here, we report on the successful growth of a series of Se doped single crystals of CeTe 3 . We found a fluctuation driven exotic magnetic rotation from the usual easy-axis ordering to an unusual hard-axis ordering. Unlike in localized magnetic systems, near-critical magnetism can increase itinerancy hand-in-hand with enhancing fluctuation of magnetism. Thus, seemingly unstable hard-axis ordering emerges through kinetic energy gain, with the self-consistent observation of enhanced magnetic fluctuation (disorder). As far as we recognize, this order-by-disorder process in fermionic system is observed for the first time within vdW materials. Our finding opens a unique experimental platform for direct visualization of the rich quasiparticle Fermi surface deformation associated with the Fermionic order-by-disorder process. Also, the search for emergent exotic phases by further tuning of quantum fluctuation is suggested as a promising future challenge.