!2296 Added qudit encoding & decoding, qutrit symmetric ansatz. Fixed…

… and improved gate decomposition function

Merge pull request !2296 from GhostArtyom/r0.10

docs/api_python/algorithm/library/mindquantum.algorithm.library.qudit_symmetric_decoding.rst

@@ -0,0 +1,23 @@
+mindquantum.algorithm.compiler.qudit_symmetric_decoding
+========================================================
+
+.. py:function:: qudit_symmetric_decoding(qubit: np.ndarray, n_qubits: int = 1)
+
+    对称性解码，将qubit对称态或矩阵解码成qudit态或矩阵。
+
+    .. math::
+
+        \begin{align}
+        \ket{00\cdots00}&\to\ket{0} \\[.5ex]
+        \frac{\ket{0\cdots01}+\ket{0\cdots010}+\ket{10\cdots0}}{\sqrt{d-1}}&\to\ket{1} \\
+        \frac{\ket{0\cdots011}+\ket{0\cdots0101}+\ket{110\cdots0}}{\sqrt{d-1}}&\to\ket{2} \\
+        \vdots&\qquad\vdots \\[.5ex]
+        \ket{11\cdots11}&\to\ket{d-1}
+        \end{align}
+
+    参数：
+        - **qubit** (np.ndarray) - 需要解码的qubit对称态或矩阵，qubit态或矩阵需满足对称性。
+        - **n_qubits** (int) - qubit对称态或矩阵的量子比特数。默认值：``1``。
+
+    返回：
+        np.ndarray，对称性解码后的qudit态或矩阵。

docs/api_python/algorithm/library/mindquantum.algorithm.library.qudit_symmetric_encoding.rst

@@ -0,0 +1,23 @@
+mindquantum.algorithm.compiler.qudit_symmetric_encoding
+========================================================
+
+.. py:function:: qudit_symmetric_encoding(qudit: np.ndarray, n_qudits: int = 1)
+
+    对称性编码，将qudit态或矩阵编码成qubit对称态或矩阵。
+
+    .. math::
+
+        \begin{align}
+        \ket{0}&\to\ket{00\cdots00} \\[.5ex]
+        \ket{1}&\to\frac{\ket{0\cdots01}+\ket{0\cdots010}+\ket{10\cdots0}}{\sqrt{d-1}} \\
+        \ket{2}&\to\frac{\ket{0\cdots011}+\ket{0\cdots0101}+\ket{110\cdots0}}{\sqrt{d-1}} \\
+        \vdots&\qquad\vdots \\[.5ex]
+        \ket{d-1}&\to\ket{11\cdots11}
+        \end{align}
+
+    参数：
+        - **qudit** (np.ndarray) - 需要编码的qudit态或矩阵。
+        - **n_qudits** (int) - qudit态或矩阵的量子位个数。默认值：``1``。
+
+    返回：
+        np.ndarray，对称性编码后的qubit对称态或矩阵。

docs/api_python/algorithm/library/mindquantum.algorithm.library.qutrit_symmetric_ansatz.rst

@@ -0,0 +1,18 @@
+mindquantum.algorithm.compiler.qutrit_symmetric_ansatz
+=======================================================
+
+.. py:function:: qutrit_symmetric_ansatz(gate: UnivMathGate, basis: str = "zyz", with_phase: bool = False)
+
+    构造一个保持任意qutrit门编码对称性的qubit ansatz。
+
+    参考文献：
+    `Synthesis of multivalued quantum logic circuits by elementary gates <https://journals.aps.org/pra/abstract/10.1103/PhysRevA.87.012325>`_，
+    `Optimal synthesis of multivalued quantum circuits <https://journals.aps.org/pra/abstract/10.1103/PhysRevA.92.062317>`_。
+
+    参数：
+        - **gate** (:class:`~.core.gates.UnivMathGate`) - 由qutrit门编码而来的qubit门。
+        - **basis** (str) - 分解的基，可以是 ``"zyz"`` 或者 ``"u3"`` 中的一个。默认值： ``"zyz"``。
+        - **with_phase** (bool) - 是否将全局相位以 :class:`~.core.gates.GlobalPhase` 的形式作用在量子线路上。默认值： ``False``。
+
+    返回：
+        :class:`~.core.circuit.Circuit`，保持qutrit编码对称性的qubit ansatz。

docs/api_python/algorithm/mindquantum.algorithm.library.rst

@@ -16,3 +16,6 @@ MindQuantum常用算法模块。
     mindquantum.algorithm.library.general_ghz_state
     mindquantum.algorithm.library.general_w_state
     mindquantum.algorithm.library.qft
+    mindquantum.algorithm.library.qudit_symmetric_decoding
+    mindquantum.algorithm.library.qudit_symmetric_encoding
+    mindquantum.algorithm.library.qutrit_symmetric_ansatz

mindquantum/algorithm/compiler/decompose/universal_decompose/two_qubit_decompose.py

@@ -209,8 +209,8 @@ def kak_decompose(gate: QuantumGate, return_u3: bool = True) -> Circuit:
     (q_left, q_right), (dr, di) = utils.simult_svd(ur, ui)
     d = dr + 1j * di
 
-    _, a0, a1 = kron_factor_4x4_to_2x2s(M @ q_left @ M_DAG)
-    _, b0, b1 = kron_factor_4x4_to_2x2s(M @ q_right.T @ M_DAG)
+    _, a1, a0 = kron_factor_4x4_to_2x2s(M @ q_left @ M_DAG)
+    _, b1, b0 = kron_factor_4x4_to_2x2s(M @ q_right.T @ M_DAG)
 
     k = linalg.inv(A) @ np.angle(np.diag(d))
     h1, h2, h3 = -k[1:]

mindquantum/algorithm/compiler/decompose/utils.py

@@ -137,7 +137,6 @@ def params_zyz(mat: np.ndarray):
     coe = linalg.det(mat) ** (-0.5)
     alpha = -np.angle(coe)
     v = coe * mat
-    v = v.round(10)
     theta = 2 * atan2(abs(v[1, 0]), abs(v[0, 0]))
     phi_lam_sum = 2 * np.angle(v[1, 1])
     phi_lam_diff = 2 * np.angle(v[1, 0])

mindquantum/algorithm/library/__init__.py

@@ -20,7 +20,11 @@
 from .general_ghz_state import general_ghz_state
 from .general_w_state import general_w_state
 from .quantum_fourier import qft
+from .qudit_mapping import qudit_symmetric_decoding, qudit_symmetric_encoding, qutrit_symmetric_ansatz
 
-__all__ = ['qft', 'amplitude_encoder', 'general_w_state', 'general_ghz_state', 'bitphaseflip_operator']
+__all__ = [
+    'qft', 'amplitude_encoder', 'general_w_state', 'general_ghz_state', 'bitphaseflip_operator',
+    'qudit_symmetric_decoding', 'qudit_symmetric_encoding', 'qutrit_symmetric_ansatz'
+]
 
 __all__.sort()