Support commutation check between Pauli-based gates and standard gates

crates/circuit/src/util.rs

@@ -47,3 +47,12 @@ pub const C_ONE: Complex64 = c64(1., 0.);
 pub const C_M_ONE: Complex64 = c64(-1., 0.);
 pub const IM: Complex64 = c64(0., 1.);
 pub const M_IM: Complex64 = c64(0., -1.);
+
+use std::f64::consts::{FRAC_PI_2, FRAC_PI_4, FRAC_PI_8, SQRT_2};
+pub const C_FRAC_PI_2: Complex64 = c64(FRAC_PI_2, 0.0);
+pub const C_FRAC_PI_4: Complex64 = c64(FRAC_PI_4, 0.0);
+pub const C_FRAC_PI_8: Complex64 = c64(FRAC_PI_8, 0.0);
+pub const C_FRAC_PI_2_SQRT_2: Complex64 = c64(FRAC_PI_2 / SQRT_2, 0.0);
+pub const C_M_FRAC_PI_4: Complex64 = c64(-FRAC_PI_4, 0.0);
+pub const C_M_FRAC_PI_8: Complex64 = c64(-FRAC_PI_8, 0.0);
+pub const C_M_FRAC_PI_2_SQRT_2: Complex64 = c64(-FRAC_PI_2 / SQRT_2, 0.0);

crates/pyext/src/lib.rs

@@ -68,6 +68,7 @@ fn _accelerate(m: &Bound<PyModule>) -> PyResult<()> {
     add_submodule(m, ::qiskit_transpiler::passes::sabre::sabre, "sabre")?;
     add_submodule(m, ::qiskit_accelerate::sampled_exp_val::sampled_exp_val, "sampled_exp_val")?;
     add_submodule(m, ::qiskit_quantum_info::sparse_observable::sparse_observable, "sparse_observable")?;
+    add_submodule(m, ::qiskit_quantum_info::sparse_observable::standard_generators::standard_generators, "standard_generators")?;
     add_submodule(m, ::qiskit_quantum_info::sparse_pauli_op::sparse_pauli_op, "sparse_pauli_op")?;
     add_submodule(m, ::qiskit_quantum_info::unitary_sim::unitary_sim, "unitary_sim")?;
     add_submodule(m, ::qiskit_transpiler::passes::split_2q_unitaries_mod, "split_2q_unitaries")?;

crates/quantum_info/src/sparse_observable/mod.rs

@@ -10,6 +10,8 @@
 // copyright notice, and modified files need to carry a notice indicating
 // that they have been altered from the originals.
 
+pub mod standard_generators;
+
 mod lookup;
 
 use hashbrown::HashSet;
@@ -4261,8 +4263,19 @@ fn coerce_to_observable<'py>(
         }
     }
 }
+#[pyfunction(name = "_generator_observable")]
+#[pyo3(signature = (gate, params = None))]
+pub fn generator_observable_py(
+    gate: qiskit_circuit::operations::StandardGate,
+    params: Option<Vec<qiskit_circuit::operations::Param>>,
+) -> Option<SparseObservable> {
+    let params = params.unwrap_or_default();
+    standard_generators::generator_observable(gate, &params)
+}
+
 pub fn sparse_observable(m: &Bound<PyModule>) -> PyResult<()> {
     m.add_class::<PySparseObservable>()?;
+    m.add_function(wrap_pyfunction!(generator_observable_py, m)?)?;
     Ok(())
 }