Memristors

Memresistors are components that could be implemented to serve as memory storage devices. Currently memresistors are an imperfect technology still requiring development. Memresistors present a great advantage in data storage because they would allow great amounts of information to be stored more efficiently and would present exponentially more efficient versions of Flash, SSD, DRAM and SRAM.

Current issues exist with the physics behind the concept of memristive systems like the HP memristor seems to be in conflict with fundamentals of non-equilibrium thermodynamics. Memristors of interest have a dynamic function with memory and may be described by any of a variety of functions of net charge.

Following the dynamic state equations of such systems, one would be able to violate Landauer's principle of the minimum possible amount of energy required to change "information" states in a system. In contrast to a linear (or nonlinear) resistor the memristor has a dynamic relationship between current and voltage including a memory of past voltages or currents. As the frequency tends to infinity, the pinched hysteresis loop degenerates to a straight line through the origin, whose slope depends on the amplitude and shape of the forcing signal. In 2011 Leon Chua has argued for a broader definition so that all 2-terminal non-volatile memory devices based on resistance switching should be considered memristors.

Meuffels and R.A linear time-invariant memristor, with a constant value for M, is simply a conventional resistor.Leon Chua has more recently said that the memristor definition could be generalized to cover all forms of 2-terminal non-volatile memory devices based on resistance switching effects and Chua has said that the memristor is the oldest known circuit element with its effects predating the resistor, capacitor and inductor.Like other two-terminal components (The memristor was originally envisioned in 1971 by circuit theorist Leon Chua as a missing non-linear passive two-terminal electrical component relating electric charge and magnetic flux linkage.Since the element "remembers" the amount of current that has passed through it in the past, it was tagged by Chua with the name "memristor". When the current is stopped, the memristor retains the last resistance that it had, and when the flow of charge starts again, the resistance of the circuit will be what it was when it was last active.