Non-Hermitian Topological Magnonics

The change in the electric field generates a magnetic field flux. This relation shows the current I and the (E_x) are proportional to the voltage, establishing the first relation between voltage and current, defining capacitance as (C). Faraday's law states that a change in magnetic flux can create electromotive force, leading to the second relation between voltage and current, defining inductance. Inductance is complex, with (\delta) representing penetration depth in normal metal. Capacitance and inductance can be used to define an effective Hamiltonian for the LC circuit, allowing for the calculation of the frequency of the photon mode, which is inversely proportional to the square root of (L) times (C). The frequency contains both real and imaginary components. This quantum approach can be used to analyze the photon mode in the normal metal ferromagnet and normal metal structure.