Small is different
Quantum-Nanoelectronics
F.K. Wilhelm
Institute for Quantum Computing (IQC)
Department of Physics and Astronomy
Department of Electrical and Computer Engineering
University of Waterloo, Canada
Waterloo, June 2007
F.K. Wilhelm
Small is different
Particles and Waves
F.K. Wilhelm
Small is different
Information as particle or wave
Classical computer
Quantum computer
Particle
Input data:
000111001010001 . . .
Wave
Multiple slits = multiple data
Output data:
1001110010001010 . . .
Results for all inputs.
Quantum algorithms
How to make sense of it?
F.K. Wilhelm
Small is different
Quantum physics at small scale
Classical physics
Quantum physics
Quantum theory: Microworld
Traditional transistor: Macroworld
Today’s transistor: 40nm
Compare molecules at 10nm: microworld
F.K. Wilhelm
Small is different
Small makes it big
Classical computing: Quantum effects detrimental
Quantum computing: Let’s use them!
Unprecedented power: N qubits store 2N classical bits
Qubits 1 2 8
18
265
Bits
2 4 256 300.000 1080
F.K. Wilhelm
Small is different
Small makes it big
Classical computing: Quantum effects detrimental
Quantum computing: Let’s use them!
Unprecedented power: N qubits store 2N classical bits
Qubits 1 2 8
18
265
Bits
2 4 256 300.000 1080
F.K. Wilhelm
Small is different
Small makes it big
Classical computing: Quantum effects detrimental
Quantum computing: Let’s use them!
Unprecedented power: N qubits store 2N classical bits
Qubits 1 2 8
18
265
Bits
2 4 256 300.000 1080
F.K. Wilhelm
Small is different
Realizations
Atoms
NMR
Optics
Nanoelectronics
F.K. Wilhelm
Small is different
Application
Algorithms:
Database search: Search 1.000.000 items in 1000 looks
Code breaking:
Today - if someone breaks your code, you add a few digits
Secure communication:
Somebody listens - you will notice
Simulate quantum systems (e.g. novel materials)
Hard and complete computer science problems?
F.K. Wilhelm
Small is different