Fixed state superposition initialisation. (#45)

Fixed-by: Michał Kordasz <Sandalas98>

Author: Sandalas98

examples/ifrqi.ipynb

@@ -4,5 +4,7 @@
 
 
 def init(n_qubits: int) -> Statevector:
-    state = np.tile([1, 0], 2**(n_qubits-4))
+    base_state = np.zeros(2**4, dtype=int)
+    base_state[0] = 1
+    state = np.tile(base_state, 2**(n_qubits-4))
     return Statevector(state)

examples/mcqi.ipynb

@@ -2,5 +2,7 @@
 from qiskit.quantum_info import Statevector
 
 def init(n_qubits: int) -> Statevector:
-    state = np.tile([1, 0], 2**(n_qubits - 3))
+    base_state = np.zeros(2**3, dtype=int)
+    base_state[0] = 1
+    state = np.tile(base_state, 2**(n_qubits - 3))
     return Statevector(state)

geqie/encodings/ifrqi/init.py

@@ -3,5 +3,7 @@
 from qiskit.quantum_info import Statevector
 
 def init(n_qubits: int) -> Statevector:
-    state = np.tile([1, 0], 2**(n_qubits - 10))
+    base_state = np.zeros(2**10, dtype=int)
+    base_state[0] = 1
+    state = np.tile(base_state, 2**(n_qubits - 10))
     return Statevector(state)

geqie/encodings/mcqi/init.py

@@ -3,5 +3,7 @@
 from qiskit.quantum_info import Statevector
 
 def init(n_qubits: int) -> Statevector:
-    state = np.tile([1, 0], 2**(n_qubits - 8))
+    base_state = np.zeros(2**8, dtype=int)
+    base_state[0] = 1
+    state = np.tile(base_state, 2**(n_qubits - 8))
     return Statevector(state)

geqie/encodings/ncqi/init.py

@@ -2,6 +2,9 @@
 
 from qiskit.quantum_info import Statevector
 
+
 def init(n_qubits: int) -> Statevector:
-    state = np.tile([1], 2**(n_qubits - 3))
+    base_state = np.zeros(2**3, dtype=int)
+    base_state[0] = 1
+    state = np.tile(base_state, 2 ** (n_qubits - 3))
     return Statevector(state)

geqie/encodings/neqr/init.py

@@ -3,5 +3,7 @@
 from qiskit.quantum_info import Statevector
 
 def init(n_qubits: int) -> Statevector:
-    state = np.tile([1, 0], 2**(n_qubits - 8))
+    base_state = np.zeros(2**8, dtype=int)
+    base_state[0] = 1
+    state = np.tile(base_state, 2**(n_qubits - 8))
     return Statevector(state)

geqie/encodings/qrci/init.py

@@ -54,8 +54,7 @@ def encode(
         print(f"{init_state=}")
 
     circuit = QuantumCircuit(n_qubits)
-    if not np.all(init_state.data == 1):
-        circuit.initialize(init_state, range(n_qubits-data_vectors[0].num_qubits - 1, n_qubits), normalize=True)
+    circuit.initialize(init_state, range(n_qubits), normalize=True)
     circuit.append(U_op, range(n_qubits))
     circuit.measure_all()