The document discusses memristors, a two-terminal electrical component that remembers the amount of charge that has flowed through it. Memristors can retain their resistance even when power is removed. The document then describes how titanium dioxide memristors work using oxygen vacancies in the material to change resistance based on the direction and amount of current flow, giving it non-volatile memory capabilities. Finally, advantages of memristors are mentioned like faster operation, lower power usage, and potential applications in AI and neuromorphic computing.

1. Memristor
Arpan Deyasi
RCCIIT, Kolkata
30-06-2021 Arpan Deyasi, India 1

2. What is Memristor?
Two terminal passive electrical component
Memorize the charge flow by changing resistance
Memristor = Memory + Resistor
30-06-2021 Arpan Deyasi, India 2

3. What is Memristor?
It is a semiconductor where resistance varies as a function of flux and charge
This allows it to remember what has allows to pass through it
Retain the resistance level even after switch off the power
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4. Relationship between fundamental physical parameters
Voltage Current
Charge Flux
Capacitor
Inductor
v iR
=
q Cv
= Li
 =
d
v
dt

= dq
i
dt
=
?
?
Mq
 =
Resistor
Memristor
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5. What is Memristance?
Charge-dependent resistance
( ) ( ) ( )
V t M q I t
=
where
( ) M
d
M q
dq

=
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6. Relationships
Mq
 =
d dq
M
dt dt

=
v Mi
=
2
P Mi
=
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7. Working
Principle
Contact
2
Contact
1
TiO2
(doped)
TiO2
(undoped)
Contact
2
Contact
1
TiO2
(doped)
TiO2
(undoped)
Contact
2
Contact
1
TiO2
(doped)
TiO2
(undoped)
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8. Titanium Dioxide Memristor is a solid state device that uses nano scale thin-films
to produce a Memristor.
Working Principle
The device consists of a thin titanium dioxide film (50nm) in between two
electrodes (5nm) one Titanium and the other Platinum.
Initially, there are two layers to the titanium dioxide film, one of which has a
slight depletion of oxygen atoms.
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9. When an electric field is applied, the oxygen vacancies drift, changing the
boundary between the high-resistance and low-resistance layers.
Thus the resistance of the film as a whole is dependent on how much charge
has been passed through it in a particular direction, which is reversible by
Changing the direction of current.
Working Principle
The oxygen vacancies act as charge carriers and this implies that the depleted
layer has a much lower resistance than the no depleted layer.
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10. Hysteresis Effect
Consider one TiO2 semiconductor
with one side doped
Therefore application of bias will
push the carriers from doped to
undoped region, causes lowering
of resistance
Bias in reverse direction again
increases the resistance
V
I
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11. Characteristics of Memristor
Combination of hard-disk and RAM
Eliminates delay
Speed is inversely proportional to size
Non-volatile memory
Analog data storage possible
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12. Characteristics of Memristor
Uses anything between ‘0’ and ‘1’
Compatible with CMOS interfaces
Faster than flash memory
Larger packing density
Less power consumption
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13. Today, most computers use random access memory (RAM), which
moves very quickly as a user works but does not retain unsaved
data if power is lost.
Why Memristor?
Flash drives, on the other hand, store information when they are
not powered but work much slower.
Memristors could provide a memory that is the best of both
worlds: fast and reliable.
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14. • Spintronic Memristor
• Spin Torque Transfer Magneto resistance
• Titanium dioxide memristor
• Polymeric memristor
• Spin memristive systems
• Magnetite memristive systems
• Resonant tunnelling diode memristor
Types of Memristor
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15. Advantages of Memristor
Comparable quicker boot-up
Less power dissipation
Eliminates the need to write computer programs that replicate
small parts of brain
Better information storage owing to higher packing density
Insignificant power consumption at idle conditions as it is
non-volatile memory
Greater reliability and resiliency when power is interrupted at data centers
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16. Applications of Memristor
Analog Computations
Programmable logic and signal processing
Circuits with mimic neuromorphic and biological systems
Artificial intelligence
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