mirror qv circuit

mitiq/benchmarks/mirror_quantum_volume_circuits.py

@@ -0,0 +1,64 @@
+# Copyright (C) 2023 Unitary Fund
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+"""Functions to create a Mirror Quantum Volume Benchmarking circuit
+as defined in https://arxiv.org/abs/2303.02108."""
+
+from mitiq.benchmarks.quantum_volume_circuits import generate_quantum_volume_circuit
+import cirq
+
+def generate_mirror_qv_circuit(
+    num_qubits: int,
+    depth: int,
+    decompose: bool = False,
+    seed: Optional[int] = None,
+    return_type: Optional[str] = None,
+) -> Tuple[QPROGRAM, Sequence[Bitstring]]:
+    """Generate a mirror quantum volume circuit with the given number of qubits and
+    depth.
+
+    The generated circuit consists of a quantum volume circuit upto `depth/2` layers
+    followed by an inverse of the quantum volume portion upto `depth/2`.
+
+    The output bit-string is always supposed to be a string of zeroes. 
+
+    Args:
+        num_qubits: The number of qubits in the generated circuit.
+        depth: The number of layers in the generated circuit.
+        decompose: Recursively decomposes the randomly sampled (numerical)
+            unitary matrix gates into simpler gates.
+        seed: Seed for generating random circuit.
+        return_type: String which specifies the type of the returned
+            circuits. See the keys of ``mitiq.SUPPORTED_PROGRAM_TYPES``
+            for options. If ``None``, the returned circuits have type
+            ``cirq.Circuit``.
+
+    Returns:
+        A quantum volume circuit acting on ``num_qubits`` qubits.
+        A list of the bitstrings for the returned circuit.
+    """
+    first_half_depth = int(depth/2)
+    random_option = random.RandomState(seed)
+
+    circ = cirq.Circuit()
+    qv_half = generate_quantum_volume_circuit(num_qubits, first_half_depth, decompose, random_option)
+    mirror_qv_half = cirq.inverse(qv_half)
+    circ.append(qv_half, mirror_qv_half)
+
+    return(circ)
+
+
+
+

mitiq/benchmarks/quantum_volume_circuits.py

@@ -47,7 +47,7 @@ def generate_quantum_volume_circuit(
 
     Args:
         num_qubits: The number of qubits in the generated circuit.
-        depth: The number of qubits in the generated circuit.
+        depth: The number of layers in the generated circuit.
         decompose: Recursively decomposes the randomly sampled (numerical)
             unitary matrix gates into simpler gates.
         seed: Seed for generating random circuit.