Is there a option to use instead of tensor network contraction state vector simulator for quantum circuits? This might be useful for small sized circuits, but I would still like to use TensorCircuit s.t. I have the other options when expanding the circuit.
I am not sure that I fully understand your requirements. In general, there is no need to use state vector simulator since the tensornetwork simulator by default provided in tensorcircuit is always fast including small size problems - faster than state vector simulator in most cases.
If you really want to test some features of the state-vector simulator, you can do this in tensorcircuit by setup the contractor as
tc.set_contractor("plain"). Warning: this plain contractor mimics the behavior for state-vector simulator but it can be slow. I really don't recommend this simulator contractor unless you clearly know what you are doing.