Merge pull request #1172 from qiboteam/entanglement_entropy

Split `quantum_info.metrics` into `quantum_info.metric`, `quantum_info.entanglement`, and `quantum_info.entropies`

doc/source/api-reference/qibo.rst

@@ -1616,22 +1616,10 @@ The destabilizers can be extracted analogously with :meth:`qibo.quantum_info.cli
     :member-order: bysource
 
 
-Metrics
-^^^^^^^
-
-Set of functions that are used to calculate metrics of states, (pseudo-)distance measures
-between states, and distance measures between quantum channels.
-
-Purity
-""""""
-
-.. autofunction:: qibo.quantum_info.purity
-
-
-Impurity
-""""""""
+Entanglement measures
+^^^^^^^^^^^^^^^^^^^^^
 
-.. autofunction:: qibo.quantum_info.impurity
+Set of functions to calculate entanglement measures.
 
 
 Concurrence
@@ -1646,45 +1634,149 @@ Entanglement of formation
 .. autofunction:: qibo.quantum_info.entanglement_of_formation
 
 
-Entropy
-"""""""
+Entanglement fidelity
+"""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.entanglement_fidelity
+
+
+Meyer-Wallach entanglement
+""""""""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.meyer_wallach_entanglement
+
 
-.. autofunction:: qibo.quantum_info.entropy
+Entanglement capability
+"""""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.entangling_capability
+
+
+Entropy measures
+^^^^^^^^^^^^^^^^
+
+Set of functions to calculate entropy measures.
+
+
+Shannon entropy
+"""""""""""""""
+
+.. autofunction:: qibo.quantum_info.shannon_entropy
+
+
+Classical relative entropy
+""""""""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.classical_relative_entropy
+
+
+Classical Rényi entropy
+"""""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.classical_renyi_entropy
+
+
+Classical Rényi relative entropy
+""""""""""""""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.classical_relative_renyi_entropy
+
+
+Classical Tsallis entropy
+"""""""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.classical_tsallis_entropy
+
+
+von Neumann entropy
+"""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.von_neumann_entropy
 
 .. note::
-    ``validate`` flag allows the user to choose if the function will check if input
-    ``state`` is Hermitian or not. Default option is ``validate=False``, i.e. the
-    assumption of Hermiticity, because it is faster and, more importantly,
-    the functions are intended to be used on Hermitian inputs. When ``validate=True``
+    ``check_hermitian`` flag allows the user to choose if the function will check if input
+    ``state`` is Hermitian or not. Default option is ``check_hermitian=False``, i.e. the
+    assumption of Hermiticity. This is faster and, more importantly,
+    this function are intended to be used on Hermitian inputs. When ``check_hermitian=True``
     and ``state`` is non-Hermitian, an error will be raised when using `cupy` backend.
 
 
+Relative von Neumann entropy
+""""""""""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.relative_von_neumann_entropy
+
+.. note::
+    ``check_hermitian`` flag allows the user to choose if the function will check if input
+    ``state`` is Hermitian or not. Default option is ``check_hermitian=False``, i.e. the
+    assumption of Hermiticity. This is faster and, more importantly,
+    this function are intended to be used on Hermitian inputs. When ``check_hermitian=True``
+    and either ``state`` or ``target`` is non-Hermitian,
+    an error will be raised when using `cupy` backend.
+
+
+Rényi entropy
+"""""""""""""
+
+.. autofunction:: qibo.quantum_info.renyi_entropy
+
+
+Relative Rényi entropy
+""""""""""""""""""""""
+
+.. autofunction:: qibo.quantum_info.relative_renyi_entropy
+
+
+Tsallis entropy
+"""""""""""""""
+
+.. autofunction:: qibo.quantum_info.tsallis_entropy
+
+
 Entanglement entropy
 """"""""""""""""""""
 
 .. autofunction:: qibo.quantum_info.entanglement_entropy
 
 .. note::
-    ``validate`` flag allows the user to choose if the function will check if
+    ``check_hermitian`` flag allows the user to choose if the function will check if
     the reduced density matrix resulting from tracing out ``bipartition`` from input
-    ``state`` is Hermitian or not. Default option is ``validate=False``, i.e. the
-    assumption of Hermiticity, because it is faster and, more importantly,
-    the functions are intended to be used on Hermitian inputs. When ``validate=True``
+    ``state`` is Hermitian or not. Default option is ``check_hermitian=False``, i.e. the
+    assumption of Hermiticity. This is faster and, more importantly,
+    this function are intended to be used on Hermitian inputs. When ``check_hermitian=True``
     and the reduced density matrix is non-Hermitian, an error will be raised
     when using `cupy` backend.
 
 
+Metrics
+^^^^^^^
+
+Set of functions that are used to calculate metrics of states, (pseudo-)distance measures
+between states, and distance measures between quantum channels.
+
+Purity
+""""""
+
+.. autofunction:: qibo.quantum_info.purity
+
+
+Impurity
+""""""""
+
+.. autofunction:: qibo.quantum_info.impurity
+
+
 Trace distance
 """"""""""""""
 
 .. autofunction:: qibo.quantum_info.trace_distance
 
 .. note::
-    ``validate`` flag allows the user to choose if the function will check if difference
+    ``check_hermitian`` flag allows the user to choose if the function will check if difference
     between inputs, ``state - target``, is Hermitian or not. Default option is
-    ``validate=False``, i.e. the assumption of Hermiticity, because it is faster and,
+    ``check_hermitian=False``, i.e. the assumption of Hermiticity, because it is faster and,
     more importantly, the functions are intended to be used on Hermitian inputs.
-    When ``validate=True`` and ``state - target`` is non-Hermitian, an error will be
+    When ``check_hermitian=True`` and ``state - target`` is non-Hermitian, an error will be
     raised when using `cupy` backend.
 
 
@@ -1718,12 +1810,6 @@ Bures distance
 .. autofunction:: qibo.quantum_info.bures_distance
 
 
-Entanglement fidelity
-"""""""""""""""""""""
-
-.. autofunction:: qibo.quantum_info.entanglement_fidelity
-
-
 Process fidelity
 """"""""""""""""
 
@@ -1754,18 +1840,6 @@ Diamond Norm
 .. autofunction:: qibo.quantum_info.diamond_norm
 
 
-Meyer-Wallach entanglement
-""""""""""""""""""""""""""
-
-.. autofunction:: qibo.quantum_info.meyer_wallach_entanglement
-
-
-Entanglement capability
-"""""""""""""""""""""""
-
-.. autofunction:: qibo.quantum_info.entangling_capability
-
-
 Expressibility of parameterized quantum circuits
 """"""""""""""""""""""""""""""""""""""""""""""""
 
@@ -2183,18 +2257,6 @@ Hadamard Transform
 .. autofunction:: qibo.quantum_info.hadamard_transform
 
 
-Shannon entropy
-"""""""""""""""
-
-.. autofunction:: qibo.quantum_info.shannon_entropy
-
-
-Total Variation distance
-""""""""""""""""""""""""
-
-.. autofunction:: qibo.quantum_info.total_variation_distance
-
-
 Hellinger distance
 """"""""""""""""""
 

src/qibo/callbacks.py

@@ -125,7 +125,7 @@ def nqubits(self, n: int):
             ]
 
     def apply(self, backend, state):
-        from qibo.quantum_info.metrics import entanglement_entropy
+        from qibo.quantum_info.entropies import entanglement_entropy
 
         entropy, spectrum = entanglement_entropy(
             state,

src/qibo/quantum_info/__init__.py

@@ -1,5 +1,7 @@
 from qibo.quantum_info.basis import *
 from qibo.quantum_info.clifford import *
+from qibo.quantum_info.entanglement import *
+from qibo.quantum_info.entropies import *
 from qibo.quantum_info.metrics import *
 from qibo.quantum_info.quantum_networks import *
 from qibo.quantum_info.random_ensembles import *