nanotechnology in our daily life - welcome |...
Post on 14-May-2018
222 Views
Preview:
TRANSCRIPT
Nanotechnology in our Daily LifeIridescent car paint: Based on interference colors(like a butterly, no bleaching after 5 years Miami)
Nanotechnology on our Desktops
Hard Disk
Sensor Medium
Transistor
Gate
Source Drain
Switching layer5 nm
Magnetic grain10 nm
Gate oxide4 nmWell
6 nm
When does silicon cease to be silicon?The band gap of silicon nanoclusters
Bulk Silicon
3 nm : Gap begins to change
GaAs
The Physicist’s View: Fundamental Length Scales
Quantum Electric MagneticQuantum Well:
Quantum Well LaserCapacitor:
Single Electron TransistorMagnetic Particle:
Storage Media
a = V1/3
Energy → LengthRoom temperature operation requires energieslarger than the thermal energy: kBT = 25 meV
Charging Energy2e2/ε d
Spin Flip Barrier½ M2a3
Energy Levels3h2/8m l2
d
E1
E0
l
l < 7 nm d < 9 nm a > 3 nm
Hewlett-Packard molecular memory, teramac computer
New Concepts: Molecular Electronics, Self-Assembly, Self-Correcting
Each panelx 10
In Pursuit of the Ultimate Storage Medium :1 Bit = 1 Atom
10 µm
10 nm
CD-ROM
Silicon Surface
Density x 1 000 000
1.6 nm Track
DNA
Speed versus Density
• Speed is sacrificed as density increases (less signal per bit)• Density and speed in silicon are comparable to those in DNA
Speed limit
Density limit:20 atoms/bit
top related