Merge pull request #50 from tqsd/two_qubit_control

Two qubit control

Author: stephendiadamo

dev_requirements.txt

@@ -21,7 +21,7 @@ decorator==4.4.1
 defusedxml==0.6.0
 docutils==0.15.2
 entrypoints==0.3
-EQSN==0.0.7
+eqsn
 flake8==3.7.9
 future==0.18.2
 hyperlink==19.0.0

integration_tests/test_host.py

@@ -1,5 +1,7 @@
 import unittest
-from qunetsim.components.host import Host
+
+from qunetsim.objects import Qubit
+from qunetsim.components import Host
 from random import randint
 
 
@@ -15,6 +17,32 @@ def setUpClass(cls):
     def tearDownClass(cls):
         pass
 
+    def test_get_qubits_by_id(self):
+        host = Host('A')
+        q1 = Qubit(host)
+        q2 = Qubit(host)
+        q3 = Qubit(host)
+
+        host2 = Host('B')
+        q4 = Qubit(host2)
+
+        host.add_epr('B', q1)
+        host.add_data_qubit('C', q2)
+        host.add_ghz_qubit('D', q3)
+
+        host2.add_data_qubit('A', q4)
+
+        # Test all types of qubits
+        self.assertEqual(q1, host.get_qubit_by_id(q1.id))
+        self.assertEqual(q2, host.get_qubit_by_id(q2.id))
+        self.assertEqual(q3, host.get_qubit_by_id(q3.id))
+
+        # Test getting qubits from other hosts
+        self.assertIsNone(host.get_qubit_by_id(q4.id))
+
+        # Test getting qubits that don't exist
+        self.assertIsNone(host.get_qubit_by_id('fake'))
+
     # @unittest.skip('')
     def test_connections(self):
         name = "A"

integration_tests/test_quantum_storage.py

@@ -2,9 +2,13 @@
 import uuid
 
 from qunetsim.objects import QuantumStorage
+from qunetsim.utils.constants import Constants
 
 
 class FakeQubit(object):
+    """
+    A qubit object that has fewer properties to test quantum storage.
+    """
 
     def __init__(self, id=None):
         if id is not None:
@@ -146,3 +150,17 @@ def test_change_id_of_qubits(self):
         self.assertEqual(q1, None)
         q2 = storage.get_qubit_from_host('Bob', new_id2)
         self.assertNotEqual(q2, None)
+
+    def test_get_qubit_by_id(self):
+        q1 = FakeQubit()
+        q2 = FakeQubit()
+        q3 = FakeQubit()
+
+        storage = QuantumStorage()
+        storage.add_qubit_from_host(q1, from_host_id='S', purpose=Constants.DATA)
+        storage.add_qubit_from_host(q2, from_host_id='T', purpose=Constants.EPR)
+        storage.add_qubit_from_host(q3, from_host_id='V', purpose=Constants.GHZ)
+
+        self.assertEqual(q1, storage.get_qubit_by_id(q1.id))
+        self.assertEqual(q2, storage.get_qubit_by_id(q2.id))
+        self.assertEqual(q3, storage.get_qubit_by_id(q3.id))

qunetsim/backends/cqc_backend.py

@@ -339,7 +339,7 @@ def custom_gate(self, qubit, gate):
             qubit(Qubit): Qubit to which the gate is applied.
             gate(np.ndarray): 2x2 array of the gate.
         """
-        raise(EnvironmentError("Not implemented for this backend!"))
+        raise (EnvironmentError("Not implemented for this backend!"))
 
     def custom_controlled_gate(self, qubit, target, gate):
         """
@@ -350,7 +350,7 @@ def custom_controlled_gate(self, qubit, target, gate):
             target(Qubit): Qubit on which the gate is applied.
             gate(nd.array): 2x2 array for the gate applied to target.
         """
-        raise(EnvironmentError("Not implemented for this backend!"))
+        raise (EnvironmentError("Not implemented for this backend!"))
 
     def custom_two_qubit_gate(self, qubit1, qubit2, gate):
         """
@@ -361,7 +361,19 @@ def custom_two_qubit_gate(self, qubit1, qubit2, gate):
             qubit2(Qubit): Second qubit of the gate.
             gate(np.ndarray): 4x4 array for the gate applied.
         """
-        raise(EnvironmentError("Not implemented for this backend!"))
+        raise (EnvironmentError("Not implemented for this backend!"))
+
+    def custom_controlled_two_qubit_gate(self, qubit, target_1, target_2, gate):
+        """
+        Applies a custom gate to the target qubit, controlled by the qubit.
+
+        Args:
+            qubit (Qubit): Qubit to control the gate.
+            target_1 (Qubit): Qubit on which the gate is applied.
+            target_2 (Qubit): Qubit on which the gate is applied.
+            gate (nd.array): 4x4 array for the gate applied to target.
+        """
+        raise (EnvironmentError("Not implemented for this backend!"))
 
     def measure(self, qubit, non_destructive):
         """

qunetsim/backends/eqsn_backend.py

@@ -373,6 +373,18 @@ def custom_controlled_gate(self, qubit, target, gate):
         """
         self.eqsn.custom_controlled_gate(target.qubit, qubit.qubit, gate)
 
+    def custom_controlled_two_qubit_gate(self, qubit, target_1, target_2, gate):
+        """
+        Applies a custom gate to the target qubit, controlled by the qubit.
+
+        Args:
+            qubit (Qubit): Qubit to control the gate.
+            target_1 (Qubit): Qubit on which the gate is applied.
+            target_2 (Qubit): Qubit on which the gate is applied.
+            gate (nd.array): 4x4 array for the gate applied to target.
+        """
+        self.eqsn.custom_two_qubit_control_gate(qubit.qubit, target_1.qubit, target_2.qubit, gate)
+
     def custom_two_qubit_gate(self, qubit1, qubit2, gate):
         """
         Applies a custom two qubit gate to qubit1 \\otimes qubit2.

qunetsim/backends/projectq_backend.py

@@ -288,7 +288,7 @@ def custom_gate(self, qubit, gate):
             qubit(Qubit): Qubit to which the gate is applied.
             gate(np.ndarray): 2x2 array of the gate.
         """
-        raise(EnvironmentError("Not implemented for this backend!"))
+        raise (EnvironmentError("Not implemented for this backend!"))
 
     def custom_controlled_gate(self, qubit, target, gate):
         """
@@ -299,7 +299,7 @@ def custom_controlled_gate(self, qubit, target, gate):
             target(Qubit): Qubit on which the gate is applied.
             gate(nd.array): 2x2 array for the gate applied to target.
         """
-        raise(EnvironmentError("Not implemented for this backend!"))
+        raise (EnvironmentError("Not implemented for this backend!"))
 
     def custom_two_qubit_gate(self, qubit1, qubit2, gate):
         """
@@ -310,7 +310,19 @@ def custom_two_qubit_gate(self, qubit1, qubit2, gate):
             qubit2(Qubit): Second qubit of the gate.
             gate(np.ndarray): 4x4 array for the gate applied.
         """
-        raise(EnvironmentError("Not implemented for this backend!"))
+        raise (EnvironmentError("Not implemented for this backend!"))
+
+    def custom_controlled_two_qubit_gate(self, qubit, target_1, target_2, gate):
+        """
+        Applies a custom gate to the target qubit, controlled by the qubit.
+
+        Args:
+            qubit (Qubit): Qubit to control the gate.
+            target_1 (Qubit): Qubit on which the gate is applied.
+            target_2 (Qubit): Qubit on which the gate is applied.
+            gate (nd.array): 4x4 array for the gate applied to target.
+        """
+        raise (EnvironmentError("Not implemented for this backend!"))
 
     def measure(self, qubit, non_destructive):
         """

qunetsim/components/host.py

@@ -1334,6 +1334,17 @@ def run_protocol(self, protocol, arguments=(), blocking=False):
         else:
             return DaemonThread(protocol, args=arguments)
 
+    def get_qubit_by_id(self, q_id):
+        """
+        Return the qubit that has the id *q_id* from the quantum storage.
+
+        Args:
+            q_id (str): The ID of the qubit
+        Returns:
+            (Qubit): The qubit with the id *q_id* or None if it does not exist
+        """
+        return self._qubit_storage.get_qubit_by_id(q_id)
+
     def get_next_classical_message(self, receive_from_id, buffer, sequence_nr):
         """
         *WILL BE DELETED*

qunetsim/objects/quantum_storage.py

@@ -154,6 +154,19 @@ def check_qubit_from_host_exists(self, from_host_id, purpose=None):
         self.lock.release_write()
         return False
 
+    def get_qubit_by_id(self, q_id):
+        """
+        Return the qubit that has the id *q_id*
+
+        Args:
+            q_id (str): The ID of the qubit
+        Returns:
+            (Qubit): The qubit with the id *q_id* or None if it does not exist
+        """
+        if q_id in self._qubit_dict:
+            return list(self._qubit_dict[q_id].values())[0]
+        return None
+
     def change_qubit_id(self, from_host_id, new_id, old_id=None):
         """
         Changes the ID of a qubit. If the ID is not given, a random
@@ -242,10 +255,10 @@ def get_all_qubits_from_host(self, from_host_id, purpose=None):
 
     def _check_all_requests(self):
         """
-        Checks if any of the pending requests is now fullfilled.
+        Checks if any of the pending requests is now fulfilled.
 
         Returns:
-            If a request is fullfilled, the request is handeled and the function
+            If a request is fulfilled, the request is handled and the function
             returns the qubit of this request.
         """
         for req_id, args in self._pending_request_dict.items():
@@ -351,7 +364,9 @@ def _get_qubit_from_host(self, from_host_id, q_id, purpose):
         return None
 
     def _pop_qubit_with_id_and_host_from_qubit_dict(self, q_id, from_host_id, purpose=None):
-        def _pop_purpose_from_purpose_dict(q_id, from_host_id):
+        def _pop_purpose_from_purpose_dict():
+            nonlocal q_id, from_host_id
+
             if q_id not in self._purpose_dict:
                 return None
             pur = self._purpose_dict[q_id].pop(from_host_id, None)
@@ -361,7 +376,7 @@ def _pop_purpose_from_purpose_dict(q_id, from_host_id):
                 return pur
             return None
 
-        purp = _pop_purpose_from_purpose_dict(q_id, from_host_id)
+        purp = _pop_purpose_from_purpose_dict()
         if purp is not None:
             if purpose is None or purpose == purp:
                 qubit = self._qubit_dict[q_id].pop(from_host_id, None)
@@ -376,15 +391,16 @@ def _pop_purpose_from_purpose_dict(q_id, from_host_id):
         return None
 
     def _add_qubit_to_qubit_dict(self, qubit, purpose, from_host_id):
-        def _add_purpose_to_purpose_dict(purpose, id, from_host_id):
-            if id not in self._purpose_dict:
-                self._purpose_dict[id] = {}
-            self._purpose_dict[id][from_host_id] = purpose
+        def _add_purpose_to_purpose_dict(q_id):
+            nonlocal purpose, from_host_id
+            if q_id not in self._purpose_dict:
+                self._purpose_dict[q_id] = {}
+            self._purpose_dict[q_id][from_host_id] = purpose
 
         if qubit.id not in self._qubit_dict:
             self._qubit_dict[qubit.id] = {}
         self._qubit_dict[qubit.id][from_host_id] = qubit
-        _add_purpose_to_purpose_dict(purpose, qubit.id, from_host_id)
+        _add_purpose_to_purpose_dict(qubit.id)
 
     def _add_new_host(self, host_id):
         if host_id not in self._host_dict:
@@ -396,6 +412,14 @@ def _add_new_host(self, host_id):
     def _check_qubit_in_system(self, qubit, from_host_id, purpose=None):
         """
         True if qubit with same parameters already in the systems
+
+        Args:
+            qubit (Qubit): The qubit in question
+            from_host_id (str): The ID of the sending host
+            purpose (int): Qubit's purpose
+
+        Returns:
+            (bool): If the qubit is in the system.
         """
         if qubit.id in self._qubit_dict and \
                 from_host_id in self._qubit_dict[qubit.id]:

qunetsim/objects/qubit.py

@@ -241,21 +241,38 @@ def custom_controlled_gate(self, target, gate):
 
         self._host.backend.custom_controlled_gate(self, target, gate)
 
+    def custom_two_qubit_control_gate(self, q1, q2, gate):
+        """
+        Applies the gate *gate* to qubits q1 and q2 as a controlled gate.
+
+        Args:
+            q1 (Qubit): First qubit
+            q2 (Qubit): Second qubit
+            gate (Numpy ndarray): The gate to apply
+        """
+        if not isinstance(gate, np.ndarray):
+            raise (InputError("Only Numpy matrices are allowed"))
+        if not is_unitary(gate):
+            raise (InputError("Custom gates must be unitary operations"))
+        if gate.shape != (4, 4):
+            raise (InputError("Custom controlled gates must be 4x4 matrices"))
+
+        self._host.backend.custom_controlled_two_qubit_gate(self, q1, q2, gate)
+
     def custom_two_qubit_gate(self, other_qubit, gate):
         """
         Applies a custom 2 qubit gate.
 
         Args:
             other_qubit (Qubit): The second qubit.
             gate (Numpy ndarray): The gate
-
         """
         if not isinstance(gate, np.ndarray):
             raise (InputError("Only Numpy matrices are allowed"))
         if not is_unitary(gate):
             raise (InputError("Custom gates must be unitary operations"))
         if gate.shape != (4, 4):
-            raise (InputError("Custom controlled gates must be 2x2 matrices"))
+            raise (InputError("Custom controlled gates must be 4x4 matrices"))
 
         self._host.backend.custom_two_qubit_gate(self, other_qubit, gate)
 

qunetsim/utils/constants.py

@@ -17,6 +17,7 @@ class Constants:
     # QUBIT TYPES
     EPR = 0
     DATA = 1
+    GHZ = 2
 
     # DATA KINDS
     SIGNAL = 'signal'