Quantum Computer Speaker: 李宥宏

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

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

Possible Solution – Quantum Computer

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

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

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

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

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

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

Outline Implement of Quantum computer

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

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

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

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

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

7 Nuclear Spins programmed by radio frequency pulses detected by NMR