Microsoft Q# Day 1: Qubit Collapsed

After going through the quantum linear algebra, I am going to see some quantum concept by using Q#.

The first one I want to prove is measurement will collapse the qubit. I will use the AssertProb to verify the value with probability. The pseudo code is listed below:

1. use H gate to set the qubit to superposition
2. check the probability to 1 equals 0.5 (50%)
3. measure the qubit
4. check the qubit equals the measured value equals to 1 (100%). The qubit collapsed. 

the code listed below:

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namespace Quantum.QSharpApplication2 { open Microsoft.Quantum.Primitive; open Microsoft.Quantum.Canon; open Microsoft.Quantum.Extensions.Convert; operation Operation1 () : Unit { body(...) { using (ancilla = Qubit()) { H(ancilla); AssertProb([PauliZ], [ancilla], Zero, 0.5, "error", 1e-5); AssertProb([PauliZ], [ancilla], One, 0.5, "error", 1e-5); mutable gate = PauliZ; let mX = Measure([gate], [ancilla]); AssertProb([gate], [ancilla], mX, 1.0, "error", 1e-5); Message(ToStringD(mX == Zero ? 0. | 1.)); Reset(ancilla); } } } }