Reversible three-dimensional chirality continuum enabled by luminomagnetic superstructure in gel

Abstract

Chirality continuum is crucial for advancing fundamental theories - spanning symmetry breaking and topological invariants - and for developing functional materials with tunable chiroptical, spintronic, and magnetic properties. However, achieving chirality continuum, particularly reversible in three-dimensional solids, remains elusive due to the intrinsic difficulties in nanoscale accuracy over extended architectures. Here, we introduce a decoupled design strategy that integrates magnetic field-directed achiral superstructures of luminomagnetic nanoparticles (LMNPs) with post-curing mechanical manipulation. Under a quadrupolar magnetic field, LMNPs self-assemble into nematic superstructures that are fixed within elastomers to form a luminomagnetic gel (LMG). Under macroscopic torsion, the superstructures undergo a transition from achiral to chiral nematic phase, allowing continuous and reversible tuning between left- and right-handed states. This process converts bulk mechanical deformation into nanoscale structural reconfiguration (for instance, 45° twisting in LMG produces 0.00088° of average inter-chain angle reorientation), thereby establishing long-range chiral ordering. The emergent circularly polarized luminescence is robust and reversible, with its intensity and handedness smoothly tuned through adjusting the applied torque. Our work delivers a modular, solid-state platform for reversible chirality continuum, opening avenues for polarization engineering and high-precision/broadband chiroptical technologies.