Add fCZ_std_err entry to Specs (#751)

docs/source/changes.rst

@@ -2,8 +2,10 @@ Changelog
 =========
 
 v2.3 (Development)
-------------------
+-----------------
 
+- The CZ gate fidelity metric available in the Specs object now has its associated standard
+error, which is accessible from the method ``Specs.fCZ_std_errs``.
 
 
 v2.2 (January 4, 2019)

pyquil/device.py

@@ -36,7 +36,8 @@
 Edge = namedtuple("Edge", ["targets", "type", "dead"])
 _ISA = namedtuple("_ISA", ["qubits", "edges"])
 QubitSpecs = namedtuple("_QubitSpecs", ["id", "fRO", "f1QRB", "T1", "T2", "fActiveReset"])
-EdgeSpecs = namedtuple("_QubitQubitSpecs", ["targets", "fBellState", "fCZ", "fCPHASE"])
+EdgeSpecs = namedtuple("_QubitQubitSpecs", ["targets", "fBellState", "fCZ", "fCZ_std_err",
+                                            "fCPHASE"])
 _Specs = namedtuple("_Specs", ["qubits_specs", "edges_specs"])
 
 
@@ -241,6 +242,16 @@ def fCZs(self):
         """
         return {tuple(es.targets): es.fCZ for es in self.edges_specs}
 
+    def fCZ_std_errs(self):
+        """
+        Get a dictionary of the standard errors of the CZ fidelities from the specs,
+        keyed by targets (qubit-qubit pairs).
+
+        :return: A dictionary of CZ fidelities, normalized to unity.
+        :rtype: Dict[tuple(int, int), float]
+        """
+        return {tuple(es.targets): es.fCZ_std_err for es in self.edges_specs}
+
     def fCPHASEs(self):
         """
         Get a dictionary of CPHASE fidelities (normalized to unity) from the specs,
@@ -275,11 +286,13 @@ def to_dict(self):
                     "1-4": {
                         "fBellState": 0.93,
                         "fCZ": 0.92,
+                        "fCZ_std_err": 0.03,
                         "fCPHASE": 0.91
                     },
                     "1-5": {
                         "fBellState": 0.9,
                         "fCZ": 0.89,
+                        "fCZ_std_err": 0.05,
                         "fCPHASE": 0.88
                     },
                     ...
@@ -304,6 +317,7 @@ def to_dict(self):
                 "{}-{}".format(*es.targets): {
                     'fBellState': es.fBellState,
                     'fCZ': es.fCZ,
+                    'fCZ_std_err': es.fCZ_std_err,
                     'fCPHASE': es.fCPHASE
                 } for es in self.edges_specs
             }
@@ -330,6 +344,7 @@ def from_dict(d):
             edges_specs=sorted([EdgeSpecs(targets=[int(q) for q in e.split('-')],
                                           fBellState=especs.get('fBellState'),
                                           fCZ=especs.get('fCZ'),
+                                          fCZ_std_err=especs.get('fCZ_std_err'),
                                           fCPHASE=especs.get('fCPHASE'))
                                 for e, especs in d["2Q"].items()],
                                key=lambda edge_specs: edge_specs.targets)
@@ -358,7 +373,7 @@ def specs_from_graph(graph: nx.Graph):
     """
     qspecs = [QubitSpecs(id=q, fRO=0.90, f1QRB=0.99, T1=30e-6, T2=30e-6, fActiveReset=0.99)
               for q in graph.nodes]
-    especs = [EdgeSpecs(targets=(q1, q2), fBellState=0.90, fCZ=0.90, fCPHASE=0.80)
+    especs = [EdgeSpecs(targets=(q1, q2), fBellState=0.90, fCZ=0.90, fCZ_std_err=0.05, fCPHASE=0.80)
               for q1, q2 in graph.edges]
     return Specs(qspecs, especs)
 

pyquil/tests/conftest.py

@@ -76,21 +76,25 @@ def specs_dict():
             "0-1": {
                 "fBellState": 0.90,
                 "fCZ": 0.89,
+                "fCZ_std_err": 0.01,
                 "fCPHASE": 0.88
             },
             "1-2": {
                 "fBellState": 0.91,
                 "fCZ": 0.90,
+                "fCZ_std_err": 0.12,
                 "fCPHASE": 0.89
             },
             "2-0": {
                 "fBellState": 0.92,
                 "fCZ": 0.91,
+                "fCZ_std_err": 0.20,
                 "fCPHASE": 0.90
             },
             "0-3": {
                 "fBellState": 0.89,
                 "fCZ": 0.88,
+                "fCZ_std_err": 0.03,
                 "fCPHASE": 0.87
             }
         }

pyquil/tests/test_device.py

@@ -57,10 +57,10 @@ def test_specs(specs_dict):
             QubitSpecs(id=3, f1QRB=0.988, fRO=0.94, T1=18e-6, T2=11e-6, fActiveReset=None)
         ],
         edges_specs=[
-            EdgeSpecs(targets=[0, 1], fBellState=0.90, fCZ=0.89, fCPHASE=0.88),
-            EdgeSpecs(targets=[0, 3], fBellState=0.89, fCZ=0.88, fCPHASE=0.87),
-            EdgeSpecs(targets=[1, 2], fBellState=0.91, fCZ=0.90, fCPHASE=0.89),
-            EdgeSpecs(targets=[2, 0], fBellState=0.92, fCZ=0.91, fCPHASE=0.90)
+            EdgeSpecs(targets=[0, 1], fBellState=0.90, fCZ=0.89, fCZ_std_err=0.01, fCPHASE=0.88),
+            EdgeSpecs(targets=[0, 3], fBellState=0.89, fCZ=0.88, fCZ_std_err=0.03, fCPHASE=0.87),
+            EdgeSpecs(targets=[1, 2], fBellState=0.91, fCZ=0.90, fCZ_std_err=0.12, fCPHASE=0.89),
+            EdgeSpecs(targets=[2, 0], fBellState=0.92, fCZ=0.91, fCZ_std_err=0.20, fCPHASE=0.90)
         ])
 
     assert specs == Specs.from_dict(specs.to_dict())
@@ -72,6 +72,7 @@ def test_specs(specs_dict):
 
     assert specs.fBellStates() == {(0, 1): 0.90, (0, 3): 0.89, (1, 2): 0.91, (2, 0): 0.92}
     assert specs.fCZs() == {(0, 1): 0.89, (0, 3): 0.88, (1, 2): 0.90, (2, 0): 0.91}
+    assert specs.fCZ_std_errs() == {(0, 1): 0.01, (0, 3): 0.03, (1, 2): 0.12, (2, 0): 0.20}
     assert specs.fCPHASEs() == {(0, 1): 0.88, (0, 3): 0.87, (1, 2): 0.89, (2, 0): 0.90}