Skip to main content
Problem List
Q20.3-Qubit GHZ |GHZ-⟩ State with Negative PhaseMedium

Q20.3-Qubit GHZ ∣GHZ−⟩|GHZ-\rangle State with Negative Phase

Quantum EntanglementQubits: 3Q
Prepare the state ∣GHZ−⟩=12(∣000⟩−∣111⟩)|\text{GHZ}^-\rangle = \frac{1}{\sqrt{2}}(|000\rangle - |111\rangle) across 3 qubits.
Target Objective:
Combine a Pauli-Z phase flip with the GHZ cascade circuit to induce destructive relative phase on ∣111⟩|111\rangle.
Judge Acceptance Criteria:

Statevector fidelity must reach ≥ 99.9% with the target unitary solution.

Gates:
q[0]|0⟩
S0
S1
S2
S3
S4
S5
S6
S7
q[1]|0⟩
S0
S1
S2
S3
S4
S5
S6
S7
q[2]|0⟩
S0
S1
S2
S3
S4
S5
S6
S7
Live Python / Qiskit Code (Edit to Update Circuit)
 
Type Qiskit Python code above to update gates on wires automatically0 gates · 3Q
0 gates placed3 Qubits · 8 Steps
State Measurement Distribution:8 non-zero basis states
|100⟩0.0%
|101⟩0.0%
|110⟩0.0%
|111⟩0.0%
|000⟩100.0%
|001⟩0.0%
|010⟩0.0%
|011⟩0.0%