Topology-induced chiral photon emission from a large-scale meron lattice

Millimetre-scale meron lattices that are stable at room temperature and under zero magnetic field can be used as spin injectors in light-emitting diodes, providing 22.5% circularly polarized electroluminescence. Merons are a class of topologically protected particle-like structures created in in-plane magnetized magnetic films. The structures can act as information carriers and could be used for magnetic storage. However, the development of such applications is hampered by limitations in the size, thermal stability and magnetic-field requirements of the systems. Here we report the construction of millimetre-scale meron lattices that are stable at room temperature and under zero magnetic field. Our system is based on a trilayer structure composed of a thin iron film sandwiched between films of palladium and magnesium oxide (Pd/Fe/MgO) on a gallium nitride wafer. It is fabricated using a molecular-beam epitaxy approach that is assisted by a high magnetic field, which leads to a strong Dzyaloshinskii-Moriya interaction. The lattices can be used for chirality transfer from merons to electrons and then to photons, and we show that the meron lattices can be used as spin injectors in nitride-based light-emitting diodes. The topology-induced spin light-emitting diode can provide 22.5% circularly polarized electroluminescence at room temperature and under zero magnetic field.

Automated summary

Researchers have successfully constructed millimetre-scale meron lattices that are stable at room temperature and under zero magnetic field, which can be used as spin injectors in light-emitting diodes to provide 22.5% circularly polarized electroluminescence. These meron lattices are topological particle-like structures created in in-plane magnetized magnetic films. The lattices can transfer chirality from merons to electrons and then to photons, and it has been demonstrated that they can be used as spin injectors in nitride-based light-emitting diodes, producing circularly polarized electroluminescence at room temperature and under zero magnetic field.