Organic chiral ferromagnets with strong spin-chiroptical interactions

Abstract

The coexistence of ferromagnetism and chirality broadens the fundamental physical properties of chiral materials; however, organic chiral materials exhibiting ferromagnetism are still limited. Here, we fabricate organic chiral ferromagnets, where left-handed and right-handed organic chiral ferromagnets present a giant difference in saturation magnetization and coercivity. Such behavior can be attributed mainly to the helical arrangement of molecules generating orbital angular momentum. The chirality generates orbital angular momentum, acting as a key intermediate, and induces an interaction between the polarized spin and photon to realize spin-chiroptical coupling, where a series of circularly polarized transmissivity-magnetic field (T-H) loops is induced. Organic chiral ferromagnetic enantiomers with giant different coercivity are designed Spin interacts with photons through chirality-generated orbital angular momentum Circularly polarized transmission-magnetic field loops are realized Gao et al. report that, because of the coexistence of organic ferromagnetism and chirality, the difference in spin-lattice interaction between left-handed and right-handed chiral ferromagnets leads to a spin-chiroptical coupling effect, where the transmissivity of the incident circularly polarized light presents a hysteresis loop with a magnetic field.