Synthetic In‐Plane Magnetic Fields in Topological Plasmonic Insulator with Detachable Identical Meta‐Atoms

Abstract

Synthetic magnetic fields for photons enable photonic systems to mimic the behavior of electrons in real magnetic fields, providing unprecedented opportunities to explore novel optical phenomena and practical applications. Unlike previous methods relying on non‐identical unit cells to modulate the local band gap of each unit cell, it is demonstrated that simply rotating identical unit cells (or meta‐atoms) without inversion symmetry enables precise control over the local band gap of the Dirac cone (i.e., the Dirac mass). This approach takes advantage of the detachable nature of identical meta‐atoms and the reconfigurable feature of the metasurface, allowing convenient assembly and flexible Dirac mass manipulation. By spatially modulating the rotation angles of the meta‐atoms, the chiral zeroth Landau level can be induced, a topologically protected one‐way propagating bulk state, enabling the design of flexible Dirac waveguides. Experimental tests confirm the transmission characteristics of the Dirac waveguide and chiral zeroth Landau modes. This system realizes chiral Landau levels in optical metasurfaces with identical meta‐atoms, enabling precise pseudo‐magnetic field control. Without breaking time‐reversal symmetry, the proposed structure has the potential for designing integrated photonic devices and exploring intriguing physical phenomena through flexible control of the synthetic magnetic fields.