Target qubit
A target qubit is the qubit designated to receive or participate in the action of a quantum operation.
Building Quantum Software with Python
A target qubit is the qubit position whose differing bit values determine which quantum-state amplitudes are paired for recombination.
- How it is used
- Selects the amplitude pairs processed when a single-qubit gate transforms a multi-qubit state.
- How deep it goes
- Explains binary indexing, decimal strides, matrix recombination, and simulator implementation, while deferring general state transformations.
- Examples
- Uses three-qubit binary pairs, Hadamard transformations, uniform distributions, simulator output, and butterfly diagrams.
- What you can do after
- Apply it via a quantum-state simulator to select amplitude pairs and verify single- or multi-qubit transformations.
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Quantum Programming in Depth
A target qubit is a qubit on which a controlled gate conditionally performs its operation.
- How it is used
- Applies a controlled operation to selected target qubits during quantum-state preparation.
- How deep it goes
- Defines conditional action, basis-state behavior, and superposition linearity, while deferring controlled-gate matrix forms.
- Examples
- Uses CNOT transformations of |10⟩, |11⟩, |00⟩, and |01⟩ to demonstrate target behavior.
- What you can do after
- Evaluate controlled-gate effects on basis states and superpositions using Dirac notation.
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Related concepts
- quantum operationused by · A quantum operation is a physical or computational transformation acting on a quantum state, including unitary evolution and measurement.
- controlled quantum operationused by · A controlled quantum operation is a quantum operation applied to target systems only when specified control qubits have required states.
- phase gateconfigured by · The Z gate is a single-qubit Pauli quantum operation that leaves |0⟩ unchanged and multiplies |1⟩ by −1.
- quantum gateconfigured by · A quantum gate is an operation that transforms the state of one or more qubits, typically represented by a unitary transformation.
- butterfly patternconfigures · A butterfly pattern is a computational pattern that recombines pairs of values with a formula to produce updated values.
- control qubitconfigured by · A control qubit is a qubit whose state conditionally determines whether a controlled quantum operation acts on target qubits.
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