
Learn Quantum Computing with Python and IBM Quantum
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A non-reversible operator is an operator that is applied on a qubit(s), and if applying the same operator again on the same qubits, then the results will not return the qubits to the same state that they had prior to applying the operator.
This section will cover the non-reversible operators, specifically the measurement operator, and the reasons why they are just as important as the other operators discussed previously.
Measurement is an operator that instructs the quantum system to measure the quantum state of the system. Before we dive into how we include the measurement instruction in our quantum circuits, let’s first define what is meant by measuring the quantum state of the system.
Note that measurement outcomes are in general probabilistic. What we lose in information is the complex amplitude of each computational basis state, into which we can encode information. At best, we can rerun and measure the circuit...