Mott memristors based on field-induced carrier avalanche multiplication

We present a theory of Mott memristors whose working principle is the nonlinear carrier avalanche multiplica-tion in Mott insulators subject to strong electric fields. The internal state of the memristor, which determines its resistance, is encoded in the density of doublon and hole excitations in the Mott insulator. In the current-voltage characteristic, insulating and conducting states are separated by a negative-differential-resistance region, leading to hysteretic behavior. Under oscillating voltage, the response of a voltage-controlled, nonpolar memristive system is obtained, with retarded current and pinched hysteresis loop. As a first step towards neuromorphic applications, we demonstrate self-sustained spiking oscillations in a circuit with a parallel capacitor. Being based on electronic excitations only, this memristor is up to several orders of magnitude faster than previous proposals relying on Joule heating or ionic drift.