Memristor

What is memristor?
Memory and resistor.

V is pressure, voltage
G is condu ctance
I is current

What if the conductance got bigger or smaller as it was used?
The I-V is pinched

Not storing energy, because the histerisis go through origin point
Facts:

• broad class of resistance-changing devices
• achivable throug diffirent physical mechanizm
  • Phase change, electrostatic, redox, etc
• application
  • Oscillators: high endurance
  • Learners: incremental+low decay. circuit
  • Memory: Fast switching + low decay-> have big energy barrier between stages
  • Optimizers: high endurance + incremental
• does not imply 'non-volatile'
  • have memory--remember their history, life-span
• a lot of memristor out there, you can chose depending on your use case

TiO2 / TiO2-x memristor

TiO2 and TiO2 have different conductivity. By applying bias voltage, we can push the ion of TiO2-x to TiO2 side, and change the overall resistance.

From this youtube

1971 Prof Chua predict the existence of fundamental component that

$dFlux=Mdq$

and also,

$v(t)=R[w,i(t)]i(t)$

$dw(t)/dt=f[w,i(t)]$

with $w$ is the state variable

• pinched histerysis loop
• cannot store energy or charge. but can store information

• TiO2 is semiconductor, but if O goes, + vacant, it become conductor.
  
• when we add + voltage, the O vacant diffused (reorganized) to the left. So that the resistance of the total stack is changing.
• Any oxide can be memristor.

I vs time and V vs time. The pulse is broaden

• state variable in the function of time
• exponential of exponential

• We can stop scale down transistor size, just add layers of memristors!.

Linked notes

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