add missing adjoints for basic gates (#895)

Author: anurudhp

qualtran/bloqs/basic_gates/global_phase.py

@@ -14,6 +14,7 @@
 
 from typing import TYPE_CHECKING
 
+import attrs
 import cirq
 from attrs import frozen
 
@@ -44,6 +45,9 @@ def cirq_gate(self) -> cirq.Gate:
     def decompose_bloq(self) -> 'CompositeBloq':
         raise DecomposeTypeError(f"{self} is atomic")
 
+    def adjoint(self) -> 'GlobalPhase':
+        return attrs.evolve(self, coefficient=complex(self.coefficient).conjugate())
+
     def pretty_name(self) -> str:
         return 'GPhase'
 

qualtran/bloqs/basic_gates/su2_rotation.py

@@ -131,6 +131,15 @@ def build_composite_bloq(self, bb: 'BloqBuilder', q: 'SoquetT') -> Dict[str, 'So
         q = bb.add(ZPowGate(exponent=-self.phi / pi, global_shift=-1, eps=self.eps / 4), q=q)
         return {'q': q}
 
+    def adjoint(self) -> 'SU2RotationGate':
+        return SU2RotationGate(
+            theta=self.theta,
+            phi=-self.lambd,
+            lambd=-self.phi,
+            global_shift=-self.global_shift,
+            eps=self.eps,
+        )
+
     def pretty_name(self) -> str:
         return 'SU_2'
 

qualtran/bloqs/basic_gates/swap.py

@@ -102,6 +102,9 @@ def on_classical_vals(
     ) -> Dict[str, 'ClassicalValT']:
         return {'x': y, 'y': x}
 
+    def adjoint(self) -> 'Bloq':
+        return self
+
 
 @frozen
 class TwoBitCSwap(Bloq):

qualtran/bloqs/basic_gates/y_gate.py

@@ -41,6 +41,9 @@ class YGate(Bloq):
     def signature(self) -> 'Signature':
         return Signature.build(q=1)
 
+    def adjoint(self) -> 'Bloq':
+        return self
+
     def add_my_tensors(
         self,
         tn: qtn.TensorNetwork,