Quantum Computer
Table of Contents
(Source)
1. Resources
- IBM lecture series available in Youtube: https://www.youtube.com/playlist?app=desktop&list=PLOFEBzvs-VvqoeIypXYLLf0PY-WOQMLR3
- https://learning.quantum.ibm.com
Books:
- Eric Johnston, Nic Harrigan, Mercedes Gimeno-Segovia, Programming Quantum Computers: Essential Algorithms and Code Samples, 1st edition, O'Reilly, 2019
- Jack D. Hidary, Quantum Computing: An Applied Approach, 2nd edition, Springer, 2019.
- Michael A. Nielson, Isaac L. Chuang, Quantum Computation and Quantum Information, Cambridge University Press, 2010 (10th anniversary edition). [Recommended]
2. QUBIT
is sth that can be in one state or other, or possibly in a state.
3. Superconduction Charged Qubits
A silicon circuit that either has charge or not
3.1. Measuring a QUBIT
- Send a microwave pulse tuned for the qubit being measured.
- listen to hear a reflection
- if you have a reflection, then it is charged
- if not, it isn't
3.1.1. Measure Instruction
MEASURE q c
Measure qubit q and store into register numbered c
3.2. Gate Applications change Probabilities
Operation on quantum computer are called gates.
There are Four gates that can encode any quantum computation:
- H, Phase and T are one qubit gates
- CNOT : two qubit gate
3.2.1. H
Hadamard gate
Changes probability to 50%
3.2.2. Phase
3.2.3. T
3.2.4. CNOT
3.3. Examples
3.3.1. A coin flipping program
H 4 MEASURE 4 [13]
Now we abstract it as:
DEFCIRCUIT FLIP-COIN q c:
H q
MEASURE q c
4. n-QUBIT abstract machine
State:
- Probabilities: 2n values
- Answer: Thousands of registers
Instructions:
- MEASURE q c
- H q
- PHASE q
- T q
- CNOT p q