Add Multi Qubit Systems Measurements tutorial (microsoft#601)

Dockerfile

@@ -57,6 +57,7 @@ RUN cd ${HOME} && \
     ./scripts/prebuild-kata.sh tutorials/LinearAlgebra LinearAlgebra.ipynb && \
     ./scripts/prebuild-kata.sh tutorials/MultiQubitGates MultiQubitGates.ipynb && \
     ./scripts/prebuild-kata.sh tutorials/MultiQubitSystems MultiQubitSystems.ipynb && \
+    ./scripts/prebuild-kata.sh tutorials/MultiQubitSystemMeasurements MultiQubitSystemMeasurements.ipynb && \
     #./scripts/prebuild-kata.sh tutorials/Oracles Oracles.ipynb && \
     ./scripts/prebuild-kata.sh tutorials/Qubit Qubit.ipynb && \
     ./scripts/prebuild-kata.sh tutorials/RandomNumberGeneration RandomNumberGenerationTutorial.ipynb && \

index.ipynb

@@ -44,6 +44,8 @@
     "\n",
     "* **[Single-qubit measurements (tutorial)](./tutorials/SingleQubitSystemMeasurements/SingleQubitSystemMeasurements.ipynb)**.\n",
     "  Learn what quantum measurement is and how to use it for single-qubit systems.\n",
+    "* **[Multi-qubit measurements (tutorial)](./tutorials/MultiQubitSystemMeasurements/MultiQubitSystemMeasurements.ipynb)**.\n",
+    "  Learn to use measurements for multi-qubit systems.\n",
     "* **[Measurements](./Measurements/Measurements.ipynb)**.\n",
     "  Learn to distinguish quantum states using measurements.\n",
     "* **[Distinguish unitaries](./DistinguishUnitaries/DistinguishUnitaries.ipynb)**\\*.\n",

tutorials/MultiQubitSystemMeasurements/.iqsharp-config.json

@@ -0,0 +1 @@
+{"dump.basisStateLabelingConvention":"Bitstring"}

tutorials/MultiQubitSystemMeasurements/MultiQubitSystemMeasurements.csproj

@@ -0,0 +1,20 @@
+<Project Sdk="Microsoft.Quantum.Sdk/0.21.2112180703">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+    <PlatformTarget>x64</PlatformTarget>
+    <RootNamespace>Quantum.Kata.MultiQubitSystemMeasurements</RootNamespace>
+    <IQSharpLoadAutomatically>true</IQSharpLoadAutomatically>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Microsoft.Quantum.Katas" Version="0.21.2112180703" />
+    <PackageReference Include="Microsoft.Quantum.Xunit" Version="0.21.2112180703" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.3.0" />
+    <PackageReference Include="xunit" Version="2.3.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.1" />
+    <DotNetCliToolReference Include="dotnet-xunit" Version="2.3.1" />
+  </ItemGroup>
+
+</Project>
+

tutorials/MultiQubitSystemMeasurements/MultiQubitSystemMeasurements.sln

@@ -0,0 +1,25 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 16
+VisualStudioVersion = 16.0.32002.261
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "MultiQubitSystemMeasurements", "MultiQubitSystemMeasurements.csproj", "{4B6FFEA0-E257-4567-8FD8-26C79E7B7B55}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{4B6FFEA0-E257-4567-8FD8-26C79E7B7B55}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{4B6FFEA0-E257-4567-8FD8-26C79E7B7B55}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{4B6FFEA0-E257-4567-8FD8-26C79E7B7B55}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{4B6FFEA0-E257-4567-8FD8-26C79E7B7B55}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {5B7089BA-08A6-44AB-BA1A-CA00B0185CB4}
+	EndGlobalSection
+EndGlobal

tutorials/MultiQubitSystemMeasurements/README.md

@@ -0,0 +1,8 @@
+# Welcome!
+
+This tutorial introduces the basics of quantum measurements for multi-qubit systems.
+
+You can run the tutorial online [here](https://mybinder.org/v2/gh/Microsoft/QuantumKatas/main?filepath=tutorials/MultiQubitSystemMeasurements/MultiQubitSystemMeasurements.ipynb).
+Alternatively, you can install Jupyter and Q# on your machine, as described [here](https://docs.microsoft.com/quantum/install-guide#develop-with-jupyter-notebooks), and run the tutorial locally by navigating to this folder and starting the notebook from the command line using the following command:
+
+    jupyter notebook MultiQubitSystemMeasurements.ipynb

tutorials/MultiQubitSystemMeasurements/ReferenceImplementation.qs

@@ -0,0 +1,64 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license.
+
+//////////////////////////////////////////////////////////////////////
+// This file contains reference solutions to all tasks.
+// You should not modify anything in this file.
+// We recommend that you try to solve the tasks yourself first,
+// but feel free to look up the solution if you get stuck.
+//////////////////////////////////////////////////////////////////////
+
+namespace Quantum.Kata.MultiQubitSystemMeasurements {
+    open Microsoft.Quantum.Intrinsic;
+    open Microsoft.Quantum.Math;
+    open Microsoft.Quantum.Canon;
+    open Microsoft.Quantum.Measurement;
+
+    // Exercise 3. Identify computational basis states
+    operation BasisStateMeasurement_Reference(qs : Qubit[]) : Int {
+        // Measurement on the first qubit gives the higher bit of the answer, on the second - the lower
+        let m1 = M(qs[0]) == Zero ? 0 | 1;
+        let m2 = M(qs[1]) == Zero ? 0 | 1;
+        return m1 * 2 + m2;
+    }
+    // Exercise 5. Distinguish orthogonal states
+    operation IsPlusPlusMinus_Reference (qs : Qubit[]) : Int {
+        return Measure([PauliX], [qs[0]]) == Zero  ? 0 | 1;
+    }
+
+    // Exercise 7. State selection using partial measurements
+    operation StateSelction_Reference(qs : Qubit[], i : Int) : Unit  {
+        if (i == 0) {
+            if (M(qs[0]) == One){
+                // apply the X gate to the second qubit
+                X(qs[1]);
+            }
+        } else {
+            if (M(qs[0]) == Zero){
+                // apply the X gate to the second qubit only
+                X(qs[1]);
+            }
+        }
+    }
+
+    // Exercise 8. State preparation using partial measurements
+    operation PostSelection_Reference ( qs : Qubit[] ): Unit {
+        // Initialize the extra qubit
+        use anc = Qubit();
+        // Using the repeat-until-success pattern to prepare the right state
+        repeat {
+            ApplyToEach(H, qs);
+            Controlled X(qs, anc);
+            let res = MResetZ(anc);
+        } 
+        until (res == Zero)
+        fixup {
+            ResetAll(qs);
+        }
+    }
+
+    // Exercise 9. Two qubit parity Measurement
+    operation ParityMeasurement_Reference(qs : Qubit[]) : Int {
+        return Measure([PauliZ, PauliZ], qs) == Zero ? 0 | 1;
+    }
+}

tutorials/MultiQubitSystemMeasurements/Tasks.qs

@@ -0,0 +1,42 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT license.
+
+//////////////////////////////////////////////////////////////////
+// This file is a back end for the tasks in the tutorial.
+// We strongly recommend to use the Notebook version of the tutorial
+// to enjoy the full experience.
+//////////////////////////////////////////////////////////////////
+
+namespace Quantum.Kata.MultiQubitSystemMeasurements {
+    open Microsoft.Quantum.Intrinsic;
+    open Microsoft.Quantum.Math;
+
+    // Exercise 3. Identify computational basis states
+    operation BasisStateMeasurement(qs : Qubit[]) : Int {
+        // ...
+        return 0;
+    }
+
+    // Exercise 5. Distinguish orthogonal states
+    operation IsPlusPlusMinus(qs : Qubit[]) : Int {
+        // ...
+        return 0;
+    }
+
+    // Exercise 7. State selection using partial measurements
+    operation StateSelction(qs : Qubit[], i : Int) : Unit  {
+        // ...
+    }
+
+    // Exercise 8. State preparation using partial measurements
+    operation PostSelection( qs : Qubit[] ): Unit {
+        // ...
+    }
+
+    // Exercise 9. Two qubit parity Measurement
+    operation ParityMeasurement(qs : Qubit[]) : Int{
+        // ...
+        return 1;
+    }
+}
+