sunsided/quantum-belltest

Diving into the Q# language

Q# - Bell Test Sample

Installing the SDK / Runtime

The SDK is based on the dotnet tooling. Install Q# support (see here) using:

dotnet new -i Microsoft.Quantum.ProjectTemplates

You can install the Visual Studio Code extension from here by executing

ext install quantum.quantum-devkit-vscode

within Visual Studio Code.

Bell Test Example

Following Writing a Quantum Program, to create a new project, run:

dotnet new console -lang Q# --output Bell
cd Bell 
code . # To open in Visual Studio Code.

You can build and run it on the command line using

dotnet build
dotnet run

Example output

Here's an example of the program output:

Resource estimation
-------------------
Metric         	Sum
CNOT           	1000
QubitClifford  	1000
R              	0
Measure        	4002
T              	0
Depth          	0
Width          	2
BorrowedWidth  	0

Experiment
----------
Init:Zero 0s=495  1s=505  agree=1000
Init:One  0s=499  1s=501  agree=1000

As we see, measuring a qubit's state after putting it into superposition via the Hadamard gate (H()) makes it collapse into either state |0> or |1> with a 50% chance. However, since both qubits are entangled (as a Bell pair), both measurements are always identical (1000 out of 1000 times).