Fin-Shaped Structure Based on Magneto-optical Response and Applications in Information Encryption

Multidimensional and multistage encryption is essential for enhancing information security, yet conventional approaches often suffer from slow response and material degradation. Here, we demonstrate a magneto-optical dual-responsive fin-shaped structure (FSS) that enables the creation of magnetic quantum-dot fin-shaped structure (MQDF) QR codes with rapid, nondestructive control capabilities. The FSS exhibits dual responsiveness to magnetic fields and optical excitation, leveraging the penetration properties of magnetic fields and the intrinsic fluorescence of quantum dots. In the absence of an external magnetic field, optical excitation leaves the QR code concealed in such environments. Information decryption is achieved exclusively when a directionally applied magnetic field induces controlled structural bending of the FSS. The MQDF architecture achieves a bending angle of 43°, with luminance reaching 43.89 cd/m2. This work successfully integrates magnetic control mechanisms into fluorescent-material-based information encryption through a straightforward fabrication process, establishing a paradigm for multidimensional and multistage cryptographic applications.