Well, you should open the article (it's free for researcher) and scroll down to here,
Dunno if it's that simple with reram as opposed to current flow on/off for one's and zeros which is pretty well understood.I don't really understand it all enough to really know though....
"....Bipolar resistive switching has been observed in Au/Si3N4/n+-Si and Au/Si3N4/SiO2/n+-Si capacitor-like MIS structures with insulator nanolayers represented by thin Si3N4 (6 nm) and SiO2 (2 nm) films. ..... The observed increase in conductivity of a semiconductor plate and a SiO2 interlayer significantly lowers the capacitor charging and discharging time, which determines the capacitor reading performance (response time of a memristive device)."
As you can see, WBT are targeting 1xnm scale, not the 28nm anymore. The previous technical difficulty of 1st Gen -ReRAM has been solved now by this Russian style resistive switching (on/off = read&write) mechanism. Also, you can read more in Introduction part to have more understanding about design and operation of memristor.
To sum up, it is very clear to me that WBT are aiming to catch up with Crossbar in term of size and speed. The architecture of WBT is similar to that of Sony-Micron and also 4DS, but completely different from Crossbar (unique and stand alone). Knowing that IF ReRam hit 1xnm scale, it will be more profitable than NAND . and when that announcement come ..... ^_^
