AssertPhase operation

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Warning

This documentation refers to the Classic QDK, which has been replaced by the Modern QDK.

Please see https://aka.ms/qdk.api for the API documentation for the Modern QDK.

Namespace: Microsoft.Quantum.Diagnostics

Package: Microsoft.Quantum.Standard

Asserts that the phase of an equal superposition state has the expected value.

operation AssertPhase (expected : Double, qubit : Qubit, tolerance : Double) : Unit

Description

This operation asserts that the phase $\phi$ of a quantum state that may be expressed as $\frac{e^{i t}}{\sqrt{2}}(e^{i\phi}\ket{0} + e^{-i\phi}\ket{1})$ for some arbitrary real $t$ has the expected value.

Input

expected : Double

The expected value of $\phi \in (-\pi,\pi]$.

qubit : Qubit

The qubit that stores the expected state.

tolerance : Double

Absolute tolerance on the difference between actual and expected.

Output : Unit

Example

The following assert succeeds: qubit is in state $\ket{\psi}=e^{i 0.5}\sqrt{1/2}\ket{0}+e^{i 0.5}\sqrt{1/2}\ket{1}$;

  • AssertPhase(0.0, qubit, 10e-10);

qubit is in state $\ket{\psi}=e^{i 0.5}\sqrt{1/2}\ket{0}+e^{-i 0.5}\sqrt{1/2}\ket{1}$;

  • AssertPhase(0.5, qubit, 10e-10);

qubit is in state $\ket{\psi}=e^{-i 2.2}\sqrt{1/2}\ket{0}+e^{i 0.2}\sqrt{1/2}\ket{1}$;

  • AssertPhase(-1.2, qubit, 10e-10);