Merge pull request #142 from qiboteam/dependabot/pip/urllib3-2.7.0

chore(deps-dev): bump urllib3 from 2.6.3 to 2.7.0

.pre-commit-config.yaml

@@ -14,7 +14,7 @@ repos:
     hooks:
       - id: black
   - repo: https://github.com/pycqa/isort
-    rev: 8.0.1
+    rev: 9.0.0a3
     hooks:
       - id: isort
         args: ["--profile", "black"]

poetry.lock

@@ -1,4 +1,4 @@
-# This file is automatically @generated by Poetry 2.3.3 and should not be changed by hand.
+# This file is automatically @generated by Poetry 2.2.1 and should not be changed by hand.
 
 [[package]]
 name = "alabaster"
@@ -1733,14 +1733,14 @@ files = [
 
 [[package]]
 name = "mako"
-version = "1.3.10"
+version = "1.3.11"
 description = "A super-fast templating language that borrows the best ideas from the existing templating languages."
 optional = false
 python-versions = ">=3.8"
 groups = ["main"]
 files = [
-    {file = "mako-1.3.10-py3-none-any.whl", hash = "sha256:baef24a52fc4fc514a0887ac600f9f1cff3d82c61d4d700a1fa84d597b88db59"},
+    {file = "mako-1.3.11-py3-none-any.whl", hash = "sha256:e372c6e333cf004aa736a15f425087ec977e1fcbd2966aae7f17c8dc1da27a77"},
-    {file = "mako-1.3.10.tar.gz", hash = "sha256:99579a6f39583fa7e5630a28c3c1f440e4e97a414b80372649c0ce338da2ea28"},
+    {file = "mako-1.3.11.tar.gz", hash = "sha256:071eb4ab4c5010443152255d77db7faa6ce5916f35226eb02dc34479b6858069"},
 ]
 
 [package.dependencies]
@@ -2770,7 +2770,7 @@ files = [
 
 [package.dependencies]
 latexcodec = ">=1.0.4"
-pyyaml = ">=3.1"
+pyyaml = ">=3.01"
 
 [[package]]
 name = "pybtex-docutils"
@@ -2848,20 +2848,20 @@ diagrams = ["jinja2", "railroad-diagrams"]
 
 [[package]]
 name = "pytest"
-version = "8.4.2"
+version = "9.0.3"
 description = "pytest: simple powerful testing with Python"
 optional = false
-python-versions = ">=3.9"
+python-versions = ">=3.10"
 groups = ["tests"]
 files = [
-    {file = "pytest-8.4.2-py3-none-any.whl", hash = "sha256:872f880de3fc3a5bdc88a11b39c9710c3497a547cfa9320bc3c5e62fbf272e79"},
+    {file = "pytest-9.0.3-py3-none-any.whl", hash = "sha256:2c5efc453d45394fdd706ade797c0a81091eccd1d6e4bccfcd476e2b8e0ab5d9"},
-    {file = "pytest-8.4.2.tar.gz", hash = "sha256:86c0d0b93306b961d58d62a4db4879f27fe25513d4b969df351abdddb3c30e01"},
+    {file = "pytest-9.0.3.tar.gz", hash = "sha256:b86ada508af81d19edeb213c681b1d48246c1a91d304c6c81a427674c17eb91c"},
 ]
 
 [package.dependencies]
 colorama = {version = ">=0.4", markers = "sys_platform == \"win32\""}
-iniconfig = ">=1"
+iniconfig = ">=1.0.1"
-packaging = ">=20"
+packaging = ">=22"
 pluggy = ">=1.5,<2"
 pygments = ">=2.7.2"
 
@@ -3906,14 +3906,14 @@ markers = {dev = "python_version == \"3.11\""}
 
 [[package]]
 name = "urllib3"
-version = "2.6.3"
+version = "2.7.0"
 description = "HTTP library with thread-safe connection pooling, file post, and more."
 optional = false
-python-versions = ">=3.9"
+python-versions = ">=3.10"
-groups = ["docs"]
+groups = ["dev", "docs"]
 files = [
-    {file = "urllib3-2.6.3-py3-none-any.whl", hash = "sha256:bf272323e553dfb2e87d9bfd225ca7b0f467b919d7bbd355436d3fd37cb0acd4"},
+    {file = "urllib3-2.7.0-py3-none-any.whl", hash = "sha256:9fb4c81ebbb1ce9531cce37674bbc6f1360472bc18ca9a553ede278ef7276897"},
-    {file = "urllib3-2.6.3.tar.gz", hash = "sha256:1b62b6884944a57dbe321509ab94fd4d3b307075e0c2eae991ac71ee15ad38ed"},
+    {file = "urllib3-2.7.0.tar.gz", hash = "sha256:231e0ec3b63ceb14667c67be60f2f2c40a518cb38b03af60abc813da26505f4c"},
 ]
 
 [package.extras]
@@ -3941,4 +3941,4 @@ qmatchatea = ["qmatchatea"]
 [metadata]
 lock-version = "2.1"
 python-versions = ">=3.11,<3.14"
-content-hash = "ffcf3cfc548f248b95a0ef4c341c5ce07329be8d5f2a79f207be42f2c54b8cbf"
+content-hash = "c481f345e729c8a67b6869092ce73b465f6ae8ad9594be8b8ff7590fdeeba60b"

pyproject.toml

@@ -54,7 +54,7 @@ ipython = "^8.34.0"
 optional = true
 
 [tool.poetry.group.tests.dependencies]
-pytest = "^8.0.0"
+pytest = ">=8,<10"
 pytest-cov = "^4.1.0"
 pytest-env = "^1.1.3"
 

src/qibotn/backends/quimb.py

@@ -210,7 +210,8 @@ def exp_value_observable_symbolic(
     This method takes a Qibo circuit, converts it to a Quimb tensor network circuit, and evaluates the expectation value
     of a Hamiltonian specified by three lists of strings: operators, sites, and coefficients.
     The expectation value is computed by summing the contributions from each term in the Hamiltonian, where each term's
-    expectation is calculated using Quimb's `local_expectation` function.
+    expectation is calculated applying gates to the tensor network representation of the circuit and contracting it
+    with the respective bra.
     Each operator string must act on all different qubits, i.e., for each term, the corresponding sites tuple must contain unique qubit indices.
     Example: operators_list = ['xyz', 'xyz'], sites_list = [(1,2,3), (1,2,3)], coeffs_list = [1, 2]
 
@@ -230,6 +231,7 @@ def exp_value_observable_symbolic(
     float
         The real part of the expectation value of the Hamiltonian on the given circuit state.
     """
+
     # Validate that no term acts multiple times on the same qubit (no repeated indices in a sites tuple)
     for sites in sites_list:
         if len(sites) != len(set(sites)):
@@ -238,29 +240,25 @@ def exp_value_observable_symbolic(
                 f"Invalid Hamiltonian term sites {sites}: repeated qubit indices are not allowed "
                 "within a single term (e.g. (0,0,0) is invalid).",
             )
-    quimb_circuit = self._qibo_circuit_to_quimb(
+
+    circuit_tn = self._qibo_circuit_to_quimb(
         circuit,
         quimb_circuit_type=self.circuit_ansatz,
         gate_opts={"max_bond": self.max_bond_dimension, "cutoff": self.svd_cutoff},
-    )
+    ).psi
+    bra = circuit_tn.copy().H
 
     expectation_value = 0.0
     for opstr, sites, coeff in zip(operators_list, sites_list, coeffs_list):
-
+        ket = circuit_tn.copy()
-        ops = self._string_to_quimb_operator(opstr)
         coeff = coeff.real
+        for label, site in zip(opstr, sites):
+            op_matrix = qu.pauli(label.upper())
+            ket.gate_(op_matrix, site)
+        exp_value = (bra & ket).contract(optimize=self.contraction_optimizer).real
+        expectation_value = expectation_value + coeff * exp_value
 
-        exp_values = quimb_circuit.local_expectation(
+    return expectation_value
-            ops,
-            where=sites,
-            backend=self.backend,
-            optimize=self.contractions_optimizer,
-            simplify_sequence="R",
-        )
-
-        expectation_value = expectation_value + coeff * exp_values
-
-    return self.real(expectation_value)
 
 
 def _qibo_circuit_to_quimb(
@@ -313,27 +311,6 @@ def _qibo_circuit_to_quimb(
     return circ
 
 
-def _string_to_quimb_operator(self, op_str):
-    """
-    Convert a Pauli string (e.g. 'xzy') to a Quimb operator using '&' chaining.
-
-    Parameters
-    ----------
-    op_str : str
-        A string like 'xzy', where each character is one of 'x', 'y', 'z', 'i'.
-
-    Returns
-    -------
-    qu_op : quimb.Qarray
-        The corresponding Quimb operator.
-    """
-    op_str = op_str.lower()
-    op = qu.pauli(op_str[0])
-    for c in op_str[1:]:
-        op = op & qu.pauli(c)
-    return op
-
-
 CLASSES_ROOTS = {"numpy": "Numpy", "torch": "PyTorch", "jax": "Jax"}
 
 METHODS = {
@@ -343,7 +320,6 @@ METHODS = {
     "execute_circuit": execute_circuit,
     "exp_value_observable_symbolic": exp_value_observable_symbolic,
     "_qibo_circuit_to_quimb": _qibo_circuit_to_quimb,
-    "_string_to_quimb_operator": _string_to_quimb_operator,
     "circuit_ansatz": circuit_ansatz,
 }