Refactor Gate class (1)

doc/pulse-paper/customize.py

@@ -51,7 +51,7 @@ def get_control(self, label):
         elif label[:2] == "sy":
             return 2 * np.pi * sigmay() / 2, [targets]
         else:
-            raise NotImplementError("Unknown control.")
+            raise ValueError("Unknown control.")
 
 
 class MyCompiler(GateCompiler):

doc/source/apidoc/qutip_qip.operations.rst

@@ -22,23 +22,20 @@ qutip\_qip.operations
       RY
       RZ
       H
-      SNOT
       SQRTNOT
       S
       T
       QASMU
       SWAP
       ISWAP
-      CNOT
+      CX
       SQRTSWAP
       SQRTISWAP
       BERKELEY
       SWAPALPHA
       MS
       TOFFOLI
       FREDKIN
-      CNOT
-      CSIGN
       CRX
       CRY
       CRZ
@@ -53,39 +50,6 @@ qutip\_qip.operations
 
    .. autosummary::
 
-      berkeley
-      cnot
       controlled_gate
-      cphase
-      cs_gate
-      csign
-      ct_gate
-      cy_gate
-      cz_gate
       expand_operator
-      fredkin
       gate_sequence_product
-      globalphase
-      hadamard_transform
-      iswap
-      molmer_sorensen
-      phasegate
-      qasmu_gate
-      qrot
-      qubit_clifford_group
-      rotation
-      rx
-      ry
-      rz
-      s_gate
-      snot
-      sqrtiswap
-      sqrtnot
-      sqrtswap
-      swap
-      swapalpha
-      t_gate
-      toffoli
-      x_gate
-      y_gate
-      z_gate

doc/source/qip-basics.rst

@@ -33,16 +33,16 @@ A circuit with the various gates and registers available is demonstrated below:
 .. testcode::
 
   from qutip_qip.circuit import QubitCircuit
-  from qutip_qip.operations import Gate, SWAP
+  from qutip_qip.operations import X, CX, SWAP
   from qutip import tensor, basis
 
-  qc = QubitCircuit(N=2, num_cbits=1)
+  qc = QubitCircuit(2, num_cbits=1)
 
-  qc.add_gate("SWAP", targets=[0, 1])
+  qc.add_gate(SWAP, targets=[0, 1])
   qc.add_measurement("M0", targets=[1], classical_store=0) # measurement gate
-  qc.add_gate("CNOT", controls=0, targets=1)
-  qc.add_gate("X", targets=0, classical_controls=[0]) # classically controlled gate
-  qc.add_gate("SWAP", targets=[0, 1])
+  qc.add_gate(CX, controls=0, targets=1)
+  qc.add_gate(X, targets=0, classical_controls=[0]) # classically controlled gate
+  qc.add_gate(SWAP, targets=[0, 1])
 
   print(qc.instruction)
 
@@ -53,7 +53,7 @@ A circuit with the various gates and registers available is demonstrated below:
 
     [Gate(SWAP, targets=[0, 1], controls=None, classical controls=None, control_value=None, classical_control_value=None),
     Measurement(M0, target=[1], classical_store=0),
-    Gate(CNOT, targets=[1], controls=[0], classical controls=None, control_value=1, classical_control_value=None),
+    Gate(CX, targets=[1], controls=[0], classical controls=None, control_value=1, classical_control_value=None),
     Gate(X, targets=[0], controls=None, classical controls=[0], control_value=None, classical_control_value=1),
     Gate(SWAP, targets=[0, 1], controls=None, classical controls=None, control_value=None, classical_control_value=None)]
 
@@ -148,20 +148,18 @@ Gate name                           Description
 "Z"                   Pauli-Z gate
 "S"                   Single-qubit rotation or Z90
 "T"                   Square root of S gate
-"SQRTNOT"             Square root of NOT gate
-"SNOT"                Hadamard gate
+"SQRTX"               Square root of X gate
+"H"                   Hadamard gate
 "PHASEGATE"           Add a phase one the state 1
 "CRX"                 Controlled rotation around x axis
 "CRY"                 Controlled rotation around y axis
 "CRZ"                 Controlled rotation around z axis
-"CX"                  Controlled X gate
+"CX"                  Controlled X gate (also called CNOT)
 "CY"                  Controlled Y gate
 "CZ"                  Controlled Z gate
 "CS"                  Controlled S gate
 "CT"                  Controlled T gate
 "CPHASE"              Controlled phase gate
-"CNOT"                Controlled NOT gate
-"CSIGN"               Same as CPHASE
 "QASMU"               U rotation gate used as a primitive in the QASM standard
 "BERKELEY"            Berkeley gate
 "SWAPalpha"           SWAPalpha gate
@@ -175,7 +173,7 @@ Gate name                           Description
 "GLOBALPHASE"         Global phase
 ====================  ========================================
 
-For some of the gates listed above, :class:`.QubitCircuit` also has a primitive :func:`.QubitCircuit.resolve_gates()` method that decomposes them into elementary gate sets such as CNOT or SWAP with single-qubit gates (RX, RY and RZ). However, this method is not fully optimized. It is very likely that the depth of the circuit can be further reduced by merging quantum gates. It is required that the gate resolution be carried out before the measurements to the circuit are added.
+For some of the gates listed above, :class:`.QubitCircuit` also has a primitive :func:`.QubitCircuit.resolve_gates()` method that decomposes them into elementary gate sets such as CX or SWAP with single-qubit gates (RX, RY and RZ). However, this method is not fully optimized. It is very likely that the depth of the circuit can be further reduced by merging quantum gates. It is required that the gate resolution be carried out before the measurements to the circuit are added.
 
 **Custom Gates**
 
@@ -278,13 +276,13 @@ QuTiP-QIP offers three distinct methods for visualizing quantum circuits. Below
   :include-source:
 
   from qutip_qip.circuit import QubitCircuit
-  from qutip_qip.operations import Gate
+  from qutip_qip.operations import H, CX, ISWAP
 
   # create the quantum circuit
   qc = QubitCircuit(2, num_cbits=1)
-  qc.add_gate("CNOT", controls=0, targets=1)
-  qc.add_gate("SNOT", targets=1)
-  qc.add_gate("ISWAP", targets=[0,1])
+  qc.add_gate(CX, controls=0, targets=1)
+  qc.add_gate(H, targets=1)
+  qc.add_gate(ISWAP, targets=[0,1])
   qc.add_measurement("M0", targets=1, classical_store=0)
 
   qc.draw("matplotlib", dpi=300)
@@ -295,13 +293,13 @@ QuTiP-QIP offers three distinct methods for visualizing quantum circuits. Below
   :include-source:
 
   from qutip_qip.circuit import QubitCircuit
-  from qutip_qip.operations import Gate
+  from qutip_qip.operations import H, CX, ISWAP
 
   # create the quantum circuit
   qc = QubitCircuit(2, num_cbits=1)
-  qc.add_gate("CNOT", controls=0, targets=1)
-  qc.add_gate("SNOT", targets=1)
-  qc.add_gate("ISWAP", targets=[0,1])
+  qc.add_gate(CX, controls=0, targets=1)
+  qc.add_gate(H, targets=1)
+  qc.add_gate(ISWAP, targets=[0,1])
   qc.add_measurement("M0", targets=1, classical_store=0)
 
   qc.draw("matplotlib", bulge=False, theme='dark', title="Plotting Quantum Circuit", dpi=300)
@@ -360,13 +358,13 @@ QuTiP-QIP offers three distinct methods for visualizing quantum circuits. Below
 .. testcode::
 
   from qutip_qip.circuit import QubitCircuit
-  from qutip_qip.operations import Gate
+  from qutip_qip.operations import H, CX, ISWAP
 
   # create the quantum circuit
   qc = QubitCircuit(2, num_cbits=1)
-  qc.add_gate("CNOT", controls=0, targets=1)
-  qc.add_gate("SNOT", targets=1)
-  qc.add_gate("ISWAP", targets=[0,1])
+  qc.add_gate(CX, controls=0, targets=1)
+  qc.add_gate(H, targets=1)
+  qc.add_gate(ISWAP, targets=[0,1])
   qc.add_measurement("M0", targets=1, classical_store=0)
 
   qc.draw("text")
@@ -375,7 +373,7 @@ QuTiP-QIP offers three distinct methods for visualizing quantum circuits. Below
   :options: +NORMALIZE_WHITESPACE
 
            ┌──────┐  ┌──────┐  ┌───────┐  ┌───┐   
-    q1 :───┤ CNOT ├──┤ SNOT ├──┤       ├──┤ M ├───
+    q1 :───┤  CX  ├──┤  H   ├──┤       ├──┤ M ├───
            └───┬──┘  └──────┘  │       │  └─╥─┘   
                │               │       │    ║     
     q0 :───────█───────────────┤ ISWAP ├────║─────
@@ -415,13 +413,13 @@ QuTiP-QIP offers three distinct methods for visualizing quantum circuits. Below
     .. code-block::
 
       from qutip_qip.circuit import QubitCircuit
-      from qutip_qip.operations import Gate
+      from qutip_qip.operations import H, CX, ISWAP
 
       # create the quantum circuit
       qc = QubitCircuit(2, num_cbits=1)
-      qc.add_gate("CNOT", controls=0, targets=1)
-      qc.add_gate("SNOT", targets=1)
-      qc.add_gate("ISWAP", targets=[0,1])
+      qc.add_gate(CX, controls=0, targets=1)
+      qc.add_gate(H, targets=1)
+      qc.add_gate(ISWAP, targets=[0,1])
       qc.add_measurement("M0", targets=1, classical_store=0)
 
       qc.draw("latex")

doc/source/qip-processor.rst

@@ -28,20 +28,21 @@ We will work through this example and explain briefly the workflow and all the m
     from qutip import basis
     from qutip_qip.circuit import QubitCircuit
     from qutip_qip.device import LinearSpinChain
+    from qutip_qip.operations import H, X, CX
 
     # Define a circuit
     qc = QubitCircuit(3)
-    qc.add_gate("X", targets=2)
-    qc.add_gate("SNOT", targets=0)
-    qc.add_gate("SNOT", targets=1)
-    qc.add_gate("SNOT", targets=2)
+    qc.add_gate(X, targets=2)
+    qc.add_gate(H, targets=0)
+    qc.add_gate(H, targets=1)
+    qc.add_gate(H, targets=2)
 
     # Oracle function f(x)
-    qc.add_gate("CNOT", controls=0, targets=2)
-    qc.add_gate("CNOT", controls=1, targets=2)
+    qc.add_gate(CX, controls=0, targets=2)
+    qc.add_gate(CX, controls=1, targets=2)
 
-    qc.add_gate("SNOT", targets=0)
-    qc.add_gate("SNOT", targets=1)
+    qc.add_gate(H, targets=0)
+    qc.add_gate(H, targets=1)
 
     # Run gate-level simulation
     init_state = basis([2,2,2], [0,0,0])
@@ -154,18 +155,20 @@ In the following example we plot the compiled Deutsche Jozsa algorithm:
 
     # Deutsch-Jozsa algorithm
     from qutip_qip.circuit import QubitCircuit
+    from qutip_qip.operations import X, H, CX
+
     qc = QubitCircuit(3)
-    qc.add_gate("X", targets=2)
-    qc.add_gate("SNOT", targets=0)
-    qc.add_gate("SNOT", targets=1)
-    qc.add_gate("SNOT", targets=2)
+    qc.add_gate(X, targets=2)
+    qc.add_gate(H, targets=0)
+    qc.add_gate(H, targets=1)
+    qc.add_gate(H, targets=2)
 
     # Oracle function f(x)
-    qc.add_gate("CNOT", controls=0, targets=2)
-    qc.add_gate("CNOT", controls=1, targets=2)
+    qc.add_gate(CX, controls=0, targets=2)
+    qc.add_gate(CX, controls=1, targets=2)
 
-    qc.add_gate("SNOT", targets=0)
-    qc.add_gate("SNOT", targets=1)
+    qc.add_gate(H, targets=0)
+    qc.add_gate(H, targets=1)
 
     from qutip_qip.device import LinearSpinChain
     spinchain_processor = LinearSpinChain(num_qubits=3, t2=30)  # T2 = 30
@@ -221,9 +224,9 @@ To let it find the optimal pulses, we need to give the parameters for :func:`~qu
     :context: close-figs
 
     from qutip_qip.device import OptPulseProcessor, SpinChainModel
-    setting_args = {"SNOT": {"num_tslots": 6, "evo_time": 2},
-                    "X": {"num_tslots": 1, "evo_time": 0.5},
-                    "CNOT": {"num_tslots": 12, "evo_time": 5}}
+    setting_args = {H: {"num_tslots": 6, "evo_time": 2},
+                    X: {"num_tslots": 1, "evo_time": 0.5},
+                    CX: {"num_tslots": 12, "evo_time": 5}}
     opt_processor = OptPulseProcessor(
         num_qubits=3, model=SpinChainModel(3, setup="linear"))
     opt_processor.load_circuit(  # Provide parameters for the algorithm
@@ -242,7 +245,7 @@ A compiler converts the quantum circuit to the corresponding pulse-level control
 In the framework, it is defined as an instance of the :obj:`.GateCompiler` class.
 The compilation procedure is achieved through the following steps.
 
-First, each quantum gate is decomposed into the native gates (e.g., rotation over :math:`x`, :math:`y` axes and the CNOT gate), using the existing decomposition scheme in QuTiP.
+First, each quantum gate is decomposed into the native gates (e.g., rotation over :math:`x`, :math:`y` axes and the CX gate), using the existing decomposition scheme in QuTiP.
 If a gate acts on two qubits that are not physically connected, like in the chain model and superconducting qubit model, SWAP gates are added to match the topology before the decomposition. Currently, only 1-dimensional chain structures are supported.
 
 Next, the compiler maps each quantum gate to a pulse-level control description.

doc/source/qip-qiskit.rst

@@ -4,9 +4,6 @@
 `qutip-qip` as a Qiskit backend
 **********************************
 
-This submodule was implemented by `Shreyas Pradhan <shpradhan12@gmail.com>`_ as part of Google Summer of Code 2022.
-And later updated by `Mayank Goel <mayank.goel447@gmail.com>`_ for Qiskit v2.
-
 Overview
 ===============
 

doc/source/qip-simulator.rst

@@ -14,19 +14,15 @@ examples of circuit evolution. We take a circuit from
 .. testcode::
 
     from qutip_qip.circuit import QubitCircuit
-    from qutip_qip.operations import (
-        Gate, controlled_gate, hadamard_transform)
-    def controlled_hadamard():
-        # Controlled Hadamard
-        return controlled_gate(
-            hadamard_transform(1), controls=0, targets=1, control_value=1)
-    qc = QubitCircuit(N=3, num_cbits=3)
-    qc.add_gate("QASMU", targets=[0], arg_value=[1.91063, 0, 0])
-    qc.add_gate("CH", controls=[0], targets=[1])
-    qc.add_gate("TOFFOLI", targets=[2], controls=[0, 1])
-    qc.add_gate("X", targets=[0])
-    qc.add_gate("X", targets=[1])
-    qc.add_gate("CNOT", targets=[1], controls=0)
+    from qutip_qip.operations import X, CX, CH, QASMU, TOFFOLI
+    )
+    qc = QubitCircuit(3, num_cbits=3)
+    qc.add_gate(QASMU, targets=[0], arg_value=[1.91063, 0, 0])
+    qc.add_gate(CH, controls=[0], targets=[1])
+    qc.add_gate(TOFFOLI, targets=[2], controls=[0, 1])
+    qc.add_gate(X, targets=[0])
+    qc.add_gate(X, targets=[1])
+    qc.add_gate(CX, targets=[1], controls=0)
 
 It corresponds to the following circuit:
 
@@ -210,12 +206,12 @@ just by measurement on the first qubit:
 .. testcode::
 
     qc = QubitCircuit(N=3, num_cbits=3)
-    qc.add_gate("QASMU", targets=[0], arg_value=[1.91063, 0, 0])
-    qc.add_gate("CH", controls=[0], targets=[1])
-    qc.add_gate("TOFFOLI", targets=[2], controls=[0, 1])
-    qc.add_gate("X", targets=[0])
-    qc.add_gate("X", targets=[1])
-    qc.add_gate("CNOT", targets=[1], controls=0)
+    qc.add_gate(QASMU, targets=[0], arg_value=[1.91063, 0, 0])
+    qc.add_gate(CH, controls=[0], targets=[1])
+    qc.add_gate(TOFFOLI, targets=[2], controls=[0, 1])
+    qc.add_gate(X, targets=[0])
+    qc.add_gate(X, targets=[1])
+    qc.add_gate(CX, targets=[1], controls=0)
     qc.add_measurement("M0", targets=[0], classical_store=0)
     qc.add_measurement("M0", targets=[1], classical_store=0)
     qc.add_measurement("M0", targets=[2], classical_store=0)

src/qutip_qip/algorithms/__init__.py

@@ -1,5 +1,15 @@
-from .qft import *
-from .qpe import *
-from .bit_flip import *
-from .phase_flip import *
-from .shor_code import *
+from .qft import qft, qft_steps, qft_gate_sequence
+from .qpe import qpe
+from .bit_flip import BitFlipCode
+from .phase_flip import PhaseFlipCode
+from .shor_code import ShorCode
+
+__all__ = [
+    "qft",
+    "qft_steps",
+    "qft_gate_sequence",
+    "qpe",
+    "BitFlipCode",
+    "PhaseFlipCode",
+    "ShorCode",
+]