Engineering nonlinearity into memristors for passive crossbar applications

Although TaOx memristors have demonstrated encouraging write/erase endurance and nanosecond switching speeds, the linear current-voltage (I-V) characteristic in the low resistance state limits their applications in large passive crossbar arrays. We demonstrate here that a TiO2-x/TaOx oxide heterostructure incorporated into a 50 nm x 50 nm memristor displays a very large nonlinearity such that I(V/2) approximate to I(V)/100 for V approximate to 1 volt, which is caused by current-controlled negative differential resistance in the device. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3693392]