Enhance gate register mechanism, add visualization of Bloch Sphere

quafu/elements/element_gates/c11.py

@@ -1,4 +1,4 @@
-from ..quantum_gate import ControlledGate, FixedGate
+from ..quantum_gate import ControlledGate, FixedGate, QuantumGate
 from abc import ABC
 from quafu.elements.matrices import XMatrix, YMatrix, ZMatrix, SMatrix, TMatrix, pmatrix
 from typing import Dict
@@ -13,6 +13,7 @@ class _C11Gate(ControlledGate, ABC):
     ct_dims = (1, 1, 2)
 
 
+@QuantumGate.register_gate('cx')
 class CXGate(_C11Gate, FixedGate):
     name = "CX"
 
@@ -21,20 +22,23 @@ def __init__(self, ctrl: int, targ: int):
         self.symbol = "+"
 
 
+@QuantumGate.register_gate('cy')
 class CYGate(_C11Gate, FixedGate):
     name = "CY"
 
     def __init__(self, ctrl: int, targ: int):
         _C11Gate.__init__(self, "Y", [ctrl], [targ], None, tar_matrix=YMatrix)
 
 
+@QuantumGate.register_gate('cz')
 class CZGate(_C11Gate, FixedGate):
     name = "CZ"
 
     def __init__(self, ctrl: int, targ: int):
         _C11Gate.__init__(self, "Z", [ctrl], [targ], None, tar_matrix=ZMatrix)
 
 
+@QuantumGate.register_gate('cs')
 class CSGate(_C11Gate, FixedGate):
     name = "CS"
 
@@ -45,6 +49,7 @@ def to_qasm(self):
         return "cp(pi/2) " + "q[%d],q[%d]" % (self.pos[0], self.pos[1])
 
 
+@QuantumGate.register_gate('ct')
 class CTGate(_C11Gate, FixedGate):
     name = "CT"
 
@@ -55,6 +60,7 @@ def to_qasm(self):
         return "cp(pi/4) " + "q[%d],q[%d]" % (self.pos[0], self.pos[1])
 
 
+@QuantumGate.register_gate('cp')
 class CPGate(_C11Gate):
     name = "CP"
 
@@ -64,11 +70,3 @@ def __init__(self, ctrl: int, targ: int, paras):
     @property
     def named_paras(self) -> Dict:
         return {'theta': self.paras}
-
-
-ControlledGate.register_gate(CXGate)
-ControlledGate.register_gate(CYGate)
-ControlledGate.register_gate(CZGate)
-ControlledGate.register_gate(CSGate)
-ControlledGate.register_gate(CTGate)
-ControlledGate.register_gate(CPGate)

quafu/elements/element_gates/cm1.py

@@ -1,57 +1,36 @@
-from ..quantum_gate import ControlledGate, FixedGate
+from ..quantum_gate import ControlledGate, FixedGate, QuantumGate
 from quafu.elements.matrices import XMatrix, YMatrix, ZMatrix
 
 __all__ = ['MCXGate', 'MCYGate', 'MCZGate', 'ToffoliGate']
 
 
+@QuantumGate.register_gate('mcx')
 class MCXGate(ControlledGate, FixedGate):
     name = "MCX"
 
     def __init__(self, ctrls, targ: int):
         ControlledGate.__init__(self, "X", ctrls, [targ], None, tar_matrix=XMatrix)
 
 
+@QuantumGate.register_gate('mcy')
 class MCYGate(ControlledGate, FixedGate):
     name = "MCY"
 
     def __init__(self, ctrls, targ: int):
         ControlledGate.__init__(self, "Y", ctrls, [targ], None, tar_matrix=YMatrix)
 
 
+@QuantumGate.register_gate('mcz')
 class MCZGate(ControlledGate, FixedGate):
     name = "MCZ"
 
     def __init__(self, ctrls, targ: int):
         ControlledGate.__init__(self, "Z", ctrls, [targ], None, tar_matrix=ZMatrix)
 
 
-
+@QuantumGate.register_gate('ccx')
 class ToffoliGate(ControlledGate, FixedGate):
     name = "CCX"
 
     def __init__(self, ctrl1: int, ctrl2: int, targ: int):
         ControlledGate.__init__(self, "X", [ctrl1, ctrl2], [targ], None, tar_matrix=XMatrix)
-
-
-ControlledGate.register_gate(MCXGate)
-ControlledGate.register_gate(MCYGate)
-ControlledGate.register_gate(MCZGate)
-ControlledGate.register_gate(ToffoliGate)
-
-# deprecated
-
-# class ControlledU(ControlledGate):
-#     """ Controlled gate class, where the matrix act non-trivially on target qubits"""
-#     name = 'CU'
-#
-#     def __init__(self, ctrls: List[int], u: Union[SingleQubitGate, MultiQubitGate]):
-#         self.targ_gate = u
-#         targs = u.pos
-#         if isinstance(targs, int):
-#             targs = [targs]
-#
-#         ControlledGate.__init__(self, u.name, ctrls, targs, u.paras, tar_matrix=self.targ_gate.get_targ_matrix())
-#
-#     def get_targ_matrix(self, reverse_order=False):
-#         return self.targ_gate.get_targ_matrix(reverse_order)
-# ControlledGate.register_gate(ControlledU)

quafu/elements/oracle.py

@@ -123,7 +123,7 @@ def customize_gate(cls_name: str,
         raise ValueError(f"Gate class {cls_name} already exists.")
 
     attrs = {'cls_name': cls_name,
-             'gate_structure': gate_structure,  # TODO: translate
+             'gate_structure': gate_structure,
              'qubit_num': qubit_num,
              }
 

quafu/visualisation/bloch_sphere.py

@@ -0,0 +1,95 @@
+import matplotlib.pyplot as plt
+import numpy as np
+
+"""
+Plotting state of single qubit on the Bloch sphere.
+
+TODO:
+1. Plot by density matrix, say, from single-qubit sub-system.
+2. Plot geometrical representation of quantum operations.
+3. Plot a chain of qubits.
+"""
+
+
+def angles_to_xyz(thetas, phis):
+    """Transform angles to cartesian coordinates."""
+    xs = np.sin(thetas) * np.cos(phis)
+    ys = np.sin(thetas) * np.sin(phis)
+    zs = np.cos(thetas)
+    return xs, ys, zs
+
+
+def xyz_to_angles(xs, ys, zs):
+    """Transform cartesian coordinates to angles."""
+    phis = np.arctan2(ys, xs)
+    thetas = np.arccos(zs)
+    return thetas, phis
+
+
+def hex_to_rgb(hex_color):
+    """Transform a hex color code to RGB (normalized float)."""
+    hex_color = hex_color.lstrip('#')
+    if len(hex_color) != 6:
+        raise ValueError("Invalid hex color code")
+
+    r = int(hex_color[0:2], 16) / 255
+    g = int(hex_color[2:4], 16) / 255
+    b = int(hex_color[4:6], 16) / 255
+    return r, g, b
+
+
+def plot_bloch_vector(v_x, v_y, v_z, title=""):
+    """
+    Plot the Bloch vector on the Bloch sphere.
+
+    Args:
+        v_x (float): x coordinate of the Bloch vector.
+        v_y (float): y coordinate of the Bloch vector.
+        v_z (float): z coordinate of the Bloch vector.
+        title (str): title of the plot.
+
+    Returns:
+        ax: matplotlib axes of the Bloch sphere plot.
+    """
+    fig = plt.figure()
+    ax = fig.add_subplot(111, projection='3d')
+
+    # surface of Bloch sphere
+    theta = np.linspace(0, np.pi, 21)
+    phi = np.linspace(0, 2 * np.pi, 21)
+    theta, phi = np.meshgrid(theta, phi)
+    x, y, z = angles_to_xyz(theta, phi)
+
+    surf = ax.plot_surface(x, y, z, color='white', alpha=0.2)
+    edge_color = hex_to_rgb('#000000')  # #ff7f0e
+    edge_alpha = 0.05
+    surf.set_edgecolor((edge_color[0], edge_color[1], edge_color[2], edge_alpha))
+
+    # coordinate axes inside the sphere span
+    span = np.linspace(-1.0, 1.0, 2)
+    ax.plot(span, 0 * span, zs=0, zdir="z", label="X", lw=1, color="black", alpha=0.5)
+    ax.plot(0 * span, span, zs=0, zdir="z", label="Y", lw=1, color="black", alpha=0.5)
+    ax.plot(0 * span, span, zs=0, zdir="y", label="Z", lw=1, color="black", alpha=0.5)
+
+    # coordinate values
+    ax.text(1.4, 0, 0, 'x', color='black')
+    ax.text(0, 1.2, 0, 'y', color='black')
+    ax.text(0, 0, 1.2, 'z', color='black')
+
+    # Bloch vector
+    ax.quiver(0, 0, 0, v_x, v_y, v_z, color='r')
+    v_theta, v_phi = xyz_to_angles(v_x, v_y, v_z)
+
+    # coordinates value text
+    ax.text(0, 0, 1.6, 'Bloch vector: ($\\theta=${:.2f}, $\\varphi$={:.2f})'.format(v_theta, v_phi), fontsize=8, color='red')
+    # ax.text(0, 0, 1.6, 'Bloch vector: ({:.2f}, {:.2f}, {:.2f})'.format(v_x, v_y, v_z), fontsize=8, color='red')
+
+    # Set the range of the axes
+    ax.set_box_aspect([1, 1, 1])
+    ax.set_xlim(-1, 1)
+    ax.set_ylim(-1, 1)
+    ax.set_zlim(-1, 1)
+    ax.view_init(32, 32)
+    ax.set_axis_off()
+    ax.set_title(title)
+    return ax