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@@ -7,6 +7,7 @@ import json |
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import qi, clifford, util |
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import random |
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class GraphState(object): |
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def __init__(self, nodes=[]): |
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@@ -25,7 +26,7 @@ class GraphState(object): |
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for n in nodes: |
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self.add_node(n) |
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def add_edge(self, v1, v2, data = {}): |
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def add_edge(self, v1, v2, data={}): |
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""" Add an edge between two vertices in the self """ |
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assert v1 != v2 |
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self.adj[v1][v2] = data |
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@@ -56,8 +57,8 @@ class GraphState(object): |
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""" Describe a graph as an edgelist """ |
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# TODO: inefficient |
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edges = set(tuple(sorted((i, n))) |
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for i, v in self.adj.items() |
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for n in v) |
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for i, v in self.adj.items() |
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for n in v) |
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return tuple(edges) |
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def remove_vop(self, a, avoid): |
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@@ -71,7 +72,7 @@ class GraphState(object): |
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else: |
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self.local_complementation(swap_qubit, "V ->") |
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def local_complementation(self, v, prefix = ""): |
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def local_complementation(self, v, prefix=""): |
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""" As defined in LISTING 1 of Anders & Briegel """ |
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for i, j in it.combinations(self.adj[v], 2): |
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self.toggle_edge(i, j) |
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@@ -80,56 +81,45 @@ class GraphState(object): |
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sqz_h = clifford.conjugation_table[clifford.by_name["sqz"]] |
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self.node[v]["vop"] = clifford.times_table[self.node[v]["vop"], msqx_h] |
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for i in self.adj[v]: |
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self.node[i]["vop"] = clifford.times_table[self.node[i]["vop"], sqz_h] |
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self.node[i]["vop"] = clifford.times_table[ |
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self.node[i]["vop"], sqz_h] |
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def act_local_rotation(self, v, op): |
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""" Act a local rotation """ |
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rotation = clifford.by_name[str(op)] |
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self.node[v]["vop"] = clifford.times_table[rotation, self.node[v]["vop"]] |
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self.node[v]["vop"] = clifford.times_table[ |
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rotation, self.node[v]["vop"]] |
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def act_hadamard(self, qubit): |
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""" Shorthand """ |
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self.act_local_rotation(qubit, 10) |
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def lonely(self, a, b): |
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""" Is this qubit lonely ? """ |
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return len(self.adj[a]) > (b in self.adj[a]) |
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def act_cz(self, a, b): |
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""" Act a controlled-phase gate on two qubits """ |
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ci = self.get_connection_info(a, b) |
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if ci["non1"]: |
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if self.lonely(a, b): |
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self.remove_vop(a, b) |
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ci = self.get_connection_info(a, b) |
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if ci["non2"]: |
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if self.lonely(b, a): |
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self.remove_vop(b, a) |
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ci = self.get_connection_info(a, b) |
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if ci["non1"] and not clifford.is_diagonal(self.node[a]["vop"]): |
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if self.lonely(a, b) and not clifford.is_diagonal(self.node[a]["vop"]): |
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self.remove_vop(a, b) |
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self.cz_with_table(a, b) |
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def get_connection_info(self, a, b): |
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if self.has_edge(a, b): |
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return {"was_edge": True, |
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"non1": len(self.adj.get(a)) > 1, |
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"non2": len(self.adj.get(b)) > 1} |
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else: |
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return {"was_edge": False, |
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"non1": len(self.adj.get(a)) > 0, |
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"non2": len(self.adj.get(b)) > 0} |
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def cz_with_table(self, a, b): |
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""" Run the table """ |
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ci = self.get_connection_info(a, b) |
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edge = self.has_edge(a, b) |
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new_edge, self.node[a]["vop"], self.node[ |
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b]["vop"] = clifford.cz_table[edge, self.node[a]["vop"], self.node[b]["vop"]] |
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va = self.node[a]["vop"] |
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vb = self.node[b]["vop"] |
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new_edge, self.node[a]["vop"], self.node[b]["vop"] = \ |
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clifford.cz_table[edge, va, vb] |
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if new_edge != edge: |
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self.toggle_edge(a, b) |
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def measure_z(self, node, force=None): |
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""" Measure the graph in the Z-basis """ |
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res = force if force!=None else random.choice([0, 1]) |
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res = force if force != None else random.choice([0, 1]) |
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# Disconnect |
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for neighbour in self.adj[node]: |
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@@ -163,7 +153,7 @@ class GraphState(object): |
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def __str__(self): |
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""" Represent as a string for quick debugging """ |
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node = {key: clifford.get_name(value["vop"]) |
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for key, value in self.node.items()} |
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for key, value in self.node.items()} |
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nbstr = str(self.adj) |
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return "graph:\n node: {}\n adj: {}\n".format(node, nbstr) |
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@@ -174,7 +164,7 @@ class GraphState(object): |
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def from_json(self, data): |
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""" Reconstruct from JSON """ |
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self.__init__([]) |
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#TODO |
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# TODO |
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def to_state_vector(self): |
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""" Get the full state vector """ |
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@@ -191,7 +181,7 @@ class GraphState(object): |
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def to_stabilizer(self): |
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""" Get the stabilizer of this graph """ |
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output = {a:{} for a in self.node} |
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output = {a: {} for a in self.node} |
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for a, b in it.product(self.node, self.node): |
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if a == b: |
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output[a][b] = "X" |
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@@ -214,4 +204,3 @@ class GraphState(object): |
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def __eq__(self, other): |
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""" Check equality between graphs """ |
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return self.adj == other.adj and self.node == other.node |
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