What are Memristor, Memcapacitor, and Meminductor?

Memristor, memcapacitor, and meminductor are new fundamental circuit elements, whose properties depend on the history of devices. This paper presents the physical analysis of these memory devices. Three simple examples are given for the memristor, memcapacitor, and meminductor, and are then generalized to reveal their general physical origin. It is found that the memristance, memcapacitance, and meminductance are caused by different combinations of nonlinear electric responses. The mathematical expressions for the currents through any voltage-driven memristor, memcapacitor, and meminductor are given, and the corresponding expressions for the memristance, memcapacitance, and meminductance are derived. Moreover, a method to determine the charge-flux relationship of a memristor is proposed.