The most basic example of entanglement is when we have 2 qubits, where q0 is in the |+> state and connects to q1 (which is in the |0> state) with a cnot gate:
The state is entangled, as the resulting outputs are either 00 or 11 with equal probability, which cannot be replicated with two unconnected qubits. (Statevector is [$ \frac{1}{\sqrt{2}}$ 0 0 $\frac{1}{\sqrt{2}}$]) However, q1 is initially not in a superposition (but |0> instead)
So is there a quantum circuit where all qubits are initially in a superposition, but the state is entangled?
If yes, could you please provide an example? If no, could you explain why? If nobody knows yet, then is there a general consensus on what likely is the case?
Also a side question: Would we consider q1 to be in superposition after the cnot gate? Since it kinda is.