Which term describes a link between qubits where a change to one affects the other, regardless of distance?

Which term describes a link between qubits where a change to one affects the other, regardless of distance?

• A. Superposition
• B. Noise
• C. Quantum supremacy
• D. Entanglement

Answer: (D)

Entanglement is a quantum link where two qubits share a joint state so that the condition of one qubit is inseparably tied to the condition of the other, no matter how far apart they are. When qubits are entangled, the overall state cannot be described simply as two independent states; instead, measuring one qubit instantly influences the description of the other, producing correlated outcomes that reveal the connection between them. This nonclassical tie is what makes entanglement such a powerful resource for quantum information tasks like teleportation and superdense coding. This is different from superposition, which refers to a single qubit being in a combination of states at once, not a relationship between two qubits. Noise is unwanted disturbance that degrades quantum states, and quantum supremacy concerns a quantum computer performing a task faster than any classical computer, not a property of linking qubits. Entanglement can persist across large distances, though it doesn’t allow faster-than-light communication; classical communication is still needed to compare results.

Entanglement is a quantum link where two qubits share a joint state so that the condition of one qubit is inseparably tied to the condition of the other, no matter how far apart they are. When qubits are entangled, the overall state cannot be described simply as two independent states; instead, measuring one qubit instantly influences the description of the other, producing correlated outcomes that reveal the connection between them. This nonclassical tie is what makes entanglement such a powerful resource for quantum information tasks like teleportation and superdense coding.

This is different from superposition, which refers to a single qubit being in a combination of states at once, not a relationship between two qubits. Noise is unwanted disturbance that degrades quantum states, and quantum supremacy concerns a quantum computer performing a task faster than any classical computer, not a property of linking qubits. Entanglement can persist across large distances, though it doesn’t allow faster-than-light communication; classical communication is still needed to compare results.