1. Quantum Computer
Speaker: 李宥宏

2. Outline Introduction of Quantum computer Implement of Quantum computer
Application of Quantum computer
Challenge of Quantum computer
Nowadays research of Quantum computer

3. Will the Moore’s Law be correct in the future ???

4. Possible Solution – Quantum Computer

5. Superposition principle
dual particle-wave behavior
Only kwon where the particle is
likely to be found
Superposition principle
a particle can also exist at two
places at once

6. Quantum Mechanics n-level system: any state amplitude
orthonormal basis
EX: 2-level,choice basis
possible state

7. Bits and Qubits Bit: high/low voltage  1/0
One state  either 1 or 0
represent one state at one time
EX:300 bits represent one state at one time
Qubit: exist or not in Orbit  1/0
One state  possibly 1 or 0
represent several state at one time
EX:300 qubits represent at one time

8. Detail in Qubit Two qubits system Superposition states State : 1 0
1 0
State :
0 1
State :
0 0/0 1/1 0/1 1
Superposition states

9. Quantum Parallelism Qubit: Superposition of the 0 and 1
Use different superposition state
Compute simultaneously
have fantastic power in some problem

10. Shor's factoring algorithm
use conventional algorithm
factor a number N in O ( )
use Quantum Parallelism
factor a number N in O ( )
factor the number in 400 bits
Super computer
take one billion years
Quantum computer(1000qubits)
only take few hours

11. Outline
Implement of Quantum computer

12. Qubit System Qubit System exhibit quantum phenomena
for quantum computing
control quantum state
Measure the state of qubit
Quantum error correction

13. Hardware Implement-1 Quantum Dot
Confine single electron in discrete energy level
semiconductor materials
Control by Laser
1 qubit solid-state device (about 30nm)

14. 波峰波谷連續出現superposition state
In 1999, Japan
日本電氣公司,中村泰信
波峰波谷連續出現superposition state
代表0的波谷
代表1的波峰
Quantum dot 的電子分佈圖

15. Hardware Implement-2 Ion traps Ion trap
4 rod electrodes AC 1kv MHz trap the ions
End-rings Charged to prevent escaping
ions
Ion trap

16. Stanford and IBM First demonstration (in 2001)
Shor's factoring algorithm
7 qubits system
to find the factor of 15
System tube including molecule that has 7 nuclear spins

17. 7 Nuclear Spins
programmed by radio frequency pulses
detected by NMR