Quantum Computer
Table of Contents
(Source)
1. QUBIT
is sth that can be in one state or other, or possibly in a state.
2. Superconduction Charged Qubits
A silicon circuit that either has charge or not
2.1. 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
2.1.1. Measure Instruction
MEASURE q c
Measure qubit q and store into register numbered c
2.2. 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 quit gates
- CNOT : two qubit gate
2.2.1. H
Hadamard gate
Changes probability to 50%
2.2.2. Phase
2.2.3. T
2.2.4. CNOT
2.3. Examples
2.3.1. A coin flipping program
H 4 MEASURE 4 [13]
Now we abstract it as:
DEFCIRCUIT FLIP-COIN q c:
H q
MEASURE q c
3. 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
