Conductance fluctuations in solids caused by defect migration

Conductance fluctuations caused by defect migration in randomized potential profile within the specimen of solids are considered and the problem of spectrum evaluation is solved. The noise is presented in the time domain as a superposition of local disturbances in the conductance. Each disturbance is a clustered random telegraph signal (RTS). The evaluation of the resulting spectrum is reduced to Lorentzians' summation. The approach suggested is more general compared to the known model of two-level systems (TLS) which considers defect jumps between two selected states. The criteria which are decisive for the shape of the noise spectrum are formulated. Mechanisms of conductance modulation initiated by defect migration are considered in detail. Numerical estimations for the resultant noise magnitude are also presented.