Quantum Memory Effects in Disordered Systems and Their Relation to 1/f Noise

We propose that memory effects in the conductivity of metallic systems can be produced by the same two levels systems that are responsible for the 1/f noise. Memory effects are extremely long-lived responses of the conductivity to changes in external parameters such as density or magnetic field. Using the quantum transport theory, we derive a universal relationship between the memory effect and the 1/f noise. Finally, we propose a magnetic memory effect, where the magneto-resistance is sensitive to the history of the applied magnetic field.