1. apply()
https://docs.pennylane.ai/en/stable/code/api/pennylane.QubitDevice.html#pennylane.QubitDevice.apply
1.1 Return / Side Effect
In DefaultQubit (base class of many devices), apply() returns nothing and stores something (undocumented but probably 2^n qubits state vector) at self._state.
https://github.com/PennyLaneAI/pennylane/blob/dcbe39242b5fc423656484c69d2d639d0acd5c99/pennylane/devices/default_qubit.py#L245
1.2 Rotation
2. Measurement / Observable
3. Capability
1.
apply()https://docs.pennylane.ai/en/stable/code/api/pennylane.QubitDevice.html#pennylane.QubitDevice.apply
1.1 Return / Side Effect
In
DefaultQubit(base class of many devices),apply()returns nothing and stores something (undocumented but probably 2^n qubits state vector) atself._state.https://github.com/PennyLaneAI/pennylane/blob/dcbe39242b5fc423656484c69d2d639d0acd5c99/pennylane/devices/default_qubit.py#L245
1.2 Rotation
2. Measurement / Observable
3. Capability