Sunday, May 13, 2012

Pinched hysteresis loops are the fingerprint of square law capacitors

It has been claimed by the circuit theorist Leon Chua that it is impossible to reproduce the characteristics of a memristor using only resistors, capacitors, and inductors and thus the memristor should be considered a "fourth fundamental circuit element." Stan Williams of HP Labs has claimed that pinched hysteresis loops are the fingerprint of memristors and that, based on this argument, all forms of ReRAM, phase change memory, and MRAM which demonstrate pinched hysteresis should be considered memristors.

Recently I performed circuit simulations (see link below) showing that a resistor in parallel with a nonlinear capacitor also produces the pinched hysteresis fingerprint. Thus pinched hysteresis is insufficient evidence for a "fourth fundamental circuit element."