|
|
@@ -9,6 +9,7 @@ import json, random |
|
|
|
import qi, clifford, util |
|
|
|
from stabilizer import Stabilizer |
|
|
|
|
|
|
|
|
|
|
|
class GraphState(object): |
|
|
|
|
|
|
|
""" |
|
|
@@ -31,9 +32,10 @@ class GraphState(object): |
|
|
|
self.adj = data.adj.copy() |
|
|
|
self.node = data.node.copy() |
|
|
|
for key, value in self.node.items(): |
|
|
|
self.node[key]["vop"] = data.node[key].get("vop", clifford.identity) |
|
|
|
self.node[key]["vop"] = data.node[ |
|
|
|
key].get("vop", clifford.identity) |
|
|
|
except AttributeError: |
|
|
|
try: |
|
|
|
try: |
|
|
|
# Provided with a list of node names? |
|
|
|
for n in data: |
|
|
|
self._add_node(n, vop=vop) |
|
|
@@ -46,7 +48,6 @@ class GraphState(object): |
|
|
|
""" Add a node """ |
|
|
|
self._add_node(self, *args, **kwargs) |
|
|
|
|
|
|
|
|
|
|
|
def _del_node(self, node): |
|
|
|
""" Remove a node. TODO: this is a hack right now! """ |
|
|
|
if not node in self.node: |
|
|
@@ -56,7 +57,6 @@ class GraphState(object): |
|
|
|
del self.adj[k][node] |
|
|
|
del self.adj[node] |
|
|
|
|
|
|
|
|
|
|
|
def _add_node(self, node, **kwargs): |
|
|
|
""" Add a node. By default, nodes are initialized with ``vop=``:math:`I`, i.e. they are in the :math:`|+\\rangle` state. |
|
|
|
|
|
|
@@ -78,19 +78,21 @@ class GraphState(object): |
|
|
|
default = kwargs.get("default", "identity") |
|
|
|
self.adj[node] = {} |
|
|
|
self.node[node] = {} |
|
|
|
kwargs["vop"] = clifford.by_name[str(kwargs.get("vop", "identity"))] #TODO: ugly |
|
|
|
kwargs["vop"] = clifford.by_name[ |
|
|
|
str(kwargs.get("vop", "identity"))] # TODO: ugly |
|
|
|
self.node[node].update(kwargs) |
|
|
|
|
|
|
|
def add_qubit(self, name, **kwargs): |
|
|
|
""" Add a qubit to the state. |
|
|
|
""" Add a qubit to the state. |
|
|
|
|
|
|
|
:param name: The name of the node, e.g. ``9``, ``start``. |
|
|
|
:type name: Any hashable type |
|
|
|
:param kwargs: Any extra node attributes |
|
|
|
|
|
|
|
By default, qubits are initialized in the :math:`|0\\rangle` state. Provide the optional ``vop`` argument to set the initial state. |
|
|
|
By default, qubits are initialized in the :math:`|0\\rangle` state. Provide the optional ``vop`` argument to set the initial state. |
|
|
|
""" |
|
|
|
kwargs["vop"] = clifford.by_name[str(kwargs.get("vop", "hadamard"))] #TODO: ugly |
|
|
|
kwargs["vop"] = clifford.by_name[ |
|
|
|
str(kwargs.get("vop", "hadamard"))] # TODO: ugly |
|
|
|
self._add_node(name, **kwargs) |
|
|
|
|
|
|
|
def act_circuit(self, circuit): |
|
|
@@ -224,14 +226,14 @@ class GraphState(object): |
|
|
|
:type basis: :math:`\in` ``{"px", "py", "pz"}`` |
|
|
|
:param force: Forces the measurement outcome. |
|
|
|
:type force: boolean |
|
|
|
:param detail: Get detailed information. |
|
|
|
:param detail: Get detailed information. |
|
|
|
:type detail: boolean |
|
|
|
|
|
|
|
|
|
|
|
Measurements in quantum mechanics are probabilistic. If you want to force a particular outcome :math:`\in\{0, 1\}`, use ``force``. |
|
|
|
|
|
|
|
You can get more information by setting ``detail=True``, in which case ``measure()`` returns a dictionary with the following keys: |
|
|
|
|
|
|
|
- ``outcome``: the measurement outcome. |
|
|
|
- ``outcome``: the measurement outcome. |
|
|
|
- ``determinate``: indicates whether the outcome was determinate or random. For example, measuring :math:`|0\\rangle` in :math:`\sigma_x` always gives a deterministic outcome. ``determinate`` is overridden by ``force`` -- forced outcomes are always determinate. |
|
|
|
- ``conjugated_basis``: The index of the measurement operator, rotated by the vertex operator of the measured node, i.e. :math:`U_\\text{vop} \sigma_m U_\\text{vop}^\dagger`. |
|
|
|
- ``phase``: The phase of the cojugated basis, :math:`\pm 1`. |
|
|
@@ -263,8 +265,8 @@ class GraphState(object): |
|
|
|
result = not result |
|
|
|
|
|
|
|
if detail: |
|
|
|
return {"outcome": int(result), |
|
|
|
"determinate": (determinate or force!=None), |
|
|
|
return {"outcome": int(result), |
|
|
|
"determinate": (determinate or force != None), |
|
|
|
"conjugated_basis": basis, |
|
|
|
"phase": phase, |
|
|
|
"node": node, |
|
|
@@ -312,23 +314,24 @@ class GraphState(object): |
|
|
|
|
|
|
|
def measure_sequence(self, measurements, forces=None, detail=False): |
|
|
|
""" Measures a sequence of Paulis |
|
|
|
|
|
|
|
|
|
|
|
:param measurements: The sequence of measurements to be made, in the form [(node, basis), ...] |
|
|
|
:type force: list of tuples |
|
|
|
:param force: Measurements in quantum mechanics are probabilistic. If you want to force a particular outcome, use the ``force``. List outcome force values in same order as measurements |
|
|
|
:type force: list |
|
|
|
:param detail: Provide detailed information |
|
|
|
:type detail: boolean |
|
|
|
|
|
|
|
|
|
|
|
""" |
|
|
|
forces = forces if forces != None else [random.choice([0, 1]) for i in range(len(measurements))] |
|
|
|
forces = forces if forces != None else [ |
|
|
|
random.choice([0, 1]) for i in range(len(measurements))] |
|
|
|
measurements = zip(measurements, forces) |
|
|
|
results = [] |
|
|
|
for (node, basis), force in measurements: |
|
|
|
result = self.measure(node, basis, force, detail) |
|
|
|
results += [result] |
|
|
|
return results |
|
|
|
|
|
|
|
|
|
|
|
def _toggle_edges(self, a, b): |
|
|
|
""" Toggle edges between vertex sets a and b """ |
|
|
|
# TODO: i'm pretty sure this is just a single-line it.combinations or |
|
|
@@ -352,7 +355,7 @@ class GraphState(object): |
|
|
|
else: |
|
|
|
friend = next(self.adj[node].iterkeys()) |
|
|
|
else: |
|
|
|
assert friend in self.adj[node].keys() # TODO: unnecessary assert |
|
|
|
assert friend in self.adj[node].keys() # TODO: unnecessary assert |
|
|
|
|
|
|
|
# Update the VOPs. TODO: pretty ugly |
|
|
|
if result: |
|
|
@@ -452,7 +455,7 @@ class GraphState(object): |
|
|
|
return {"node": self.node, "adj": self.adj} |
|
|
|
|
|
|
|
def from_json(self, data): |
|
|
|
""" Construct the graph from JSON data |
|
|
|
""" Construct the graph from JSON data |
|
|
|
:param data: JSON data to be read. |
|
|
|
""" |
|
|
|
self.node = data["node"] |
|
|
@@ -482,17 +485,17 @@ class GraphState(object): |
|
|
|
return state |
|
|
|
|
|
|
|
def to_stabilizer(self): |
|
|
|
""" |
|
|
|
""" |
|
|
|
Get the stabilizer representation of the state:: |
|
|
|
|
|
|
|
>>> print g.to_stabilizer() |
|
|
|
0 1 2 3 100 200 |
|
|
|
------------------------------ |
|
|
|
X Z Z X |
|
|
|
Z X Z |
|
|
|
Z Z X |
|
|
|
- Z Z |
|
|
|
X Z |
|
|
|
X Z Z X |
|
|
|
Z X Z |
|
|
|
Z Z X |
|
|
|
- Z Z |
|
|
|
X Z |
|
|
|
Z X |
|
|
|
|
|
|
|
""" |
|
|
@@ -509,4 +512,3 @@ class GraphState(object): |
|
|
|
g.adj = self.adj.copy() |
|
|
|
g.deterministic = self.deterministic |
|
|
|
return g |
|
|
|
|