added vsqs ansatz

.github/workflows/continuous_integration.yml

@@ -40,7 +40,7 @@ jobs:
         pip install qiskit==0.33.1 # Due to strange behaviour of noise model
         pip install qulacs
         pip install amazon-braket-sdk
-        pip install cirq==0.12.0
+        pip install cirq
         pip install projectq
       if: always()
 

tangelo/algorithms/variational/tests/test_vqe_solver.py

@@ -137,6 +137,31 @@ def test_simulate_qcc_h2(self):
         energy = vqe_solver.simulate()
         self.assertAlmostEqual(energy, -1.137270, delta=1e-4)
 
+    def test_simulate_vsqs_h2(self):
+        """Run VQE on H2 molecule, with vsqs ansatz, JW qubit mapping, exact simulator for both molecule input and
+        qubit_hamiltonian/hini/reference_state input
+        """
+        vqe_options = {"molecule": mol_H2_sto3g, "ansatz": BuiltInAnsatze.VSQS, "qubit_mapping": "jw",
+                       "verbose": False, "ansatz_options": {"intervals": 3, "time": 3}}
+        vqe_solver = VQESolver(vqe_options)
+        vqe_solver.build()
+
+        energy = vqe_solver.simulate()
+        self.assertAlmostEqual(energy, -1.137270, delta=1e-4)
+
+        qubit_hamiltonian = vqe_solver.qubit_hamiltonian
+        h_init = vqe_solver.ansatz.h_init
+        reference_state = vqe_solver.ansatz.prepare_reference_state()
+
+        vqe_options = {"molecule": None, "qubit_hamiltonian": qubit_hamiltonian, "ansatz": BuiltInAnsatze.VSQS, "qubit_mapping": "jw",
+                       "ansatz_options": {"intervals": 3, "time": 3, "qubit_hamiltonian": qubit_hamiltonian,
+                                          "h_init": h_init, "reference_state": reference_state}}
+        vqe_solver = VQESolver(vqe_options)
+        vqe_solver.build()
+
+        energy = vqe_solver.simulate()
+        self.assertAlmostEqual(energy, -1.137270, delta=1e-4)
+
     def test_simulate_h2_qiskit(self):
         """Run VQE on H2 molecule, with UCCSD ansatz, JW qubit mapping, initial
         parameters, exact qiskit simulator.

tangelo/algorithms/variational/vqe_solver.py

@@ -29,13 +29,7 @@
 from tangelo.toolboxes.operators import count_qubits, FermionOperator, qubitop_to_qubitham
 from tangelo.toolboxes.qubit_mappings.mapping_transform import fermion_to_qubit_mapping
 from tangelo.toolboxes.ansatz_generator.ansatz import Ansatz
-from tangelo.toolboxes.ansatz_generator.uccsd import UCCSD
-from tangelo.toolboxes.ansatz_generator.rucc import RUCC
-from tangelo.toolboxes.ansatz_generator.hea import HEA
-from tangelo.toolboxes.ansatz_generator.upccgsd import UpCCGSD
-from tangelo.toolboxes.ansatz_generator.qmf import QMF
-from tangelo.toolboxes.ansatz_generator.qcc import QCC
-from tangelo.toolboxes.ansatz_generator.variational_circuit import VariationalCircuitAnsatz
+from tangelo.toolboxes.ansatz_generator import UCCSD, RUCC, HEA, UpCCGSD, QMF, QCC, VSQS, VariationalCircuitAnsatz
 from tangelo.toolboxes.ansatz_generator.penalty_terms import combined_penalty
 from tangelo.toolboxes.post_processing.bootstrapping import get_resampled_frequencies
 from tangelo.toolboxes.ansatz_generator.fermionic_operators import number_operator, spinz_operator, spin2_operator
@@ -50,6 +44,7 @@ class BuiltInAnsatze(Enum):
     UpCCGSD = 4
     QMF = 5
     QCC = 6
+    VSQS = 7
 
 
 class VQESolver:
@@ -186,12 +181,19 @@ def build(self):
                     self.ansatz = QMF(self.molecule, self.qubit_mapping, self.up_then_down, **self.ansatz_options)
                 elif self.ansatz == BuiltInAnsatze.QCC:
                     self.ansatz = QCC(self.molecule, self.qubit_mapping, self.up_then_down, **self.ansatz_options)
+                elif self.ansatz == BuiltInAnsatze.VSQS:
+                    self.ansatz = VSQS(self.molecule, self.qubit_mapping, self.up_then_down, **self.ansatz_options)
                 else:
                     raise ValueError(f"Unsupported ansatz. Built-in ansatze:\n\t{self.builtin_ansatze}")
             elif not isinstance(self.ansatz, Ansatz):
                 raise TypeError(f"Invalid ansatz dataype. Expecting instance of Ansatz class, or one of built-in options:\n\t{self.builtin_ansatze}")
 
         # Building with a qubit Hamiltonian.
+        elif self.ansatz in [BuiltInAnsatze.HEA, BuiltInAnsatze.VSQS]:
+            if self.ansatz == BuiltInAnsatze.HEA:
+                self.ansatz = HEA(self.molecule, self.qubit_mapping, self.up_then_down, **self.ansatz_options)
+            elif self.ansatz == BuiltInAnsatze.VSQS:
+                self.ansatz = VSQS(self.molecule, self.qubit_mapping, self.up_then_down, **self.ansatz_options)
         elif not isinstance(self.ansatz, Ansatz):
             raise TypeError(f"Invalid ansatz dataype. Expecting a custom Ansatz (Ansatz class).")
 

tangelo/toolboxes/ansatz_generator/__init__.py

@@ -11,3 +11,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
+
+from .vsqs import VSQS
+from .qcc import QCC
+from .qmf import QMF
+from .uccsd import UCCSD
+from .adapt_ansatz import ADAPTAnsatz
+from .rucc import RUCC
+from .upccgsd import UpCCGSD
+from .hea import HEA
+from .variational_circuit import VariationalCircuitAnsatz

tangelo/toolboxes/ansatz_generator/ansatz_utils.py

@@ -83,7 +83,7 @@ def exp_pauliword_to_gates(pauli_word, coef, variational=True, control=None):
 
 
 def get_exponentiated_qubit_operator_circuit(qubit_op, time=1., variational=False, trotter_order=1, control=None,
-                                             return_phase=False):
+                                             return_phase=False, pauli_order=None):
     """Generate the exponentiation of a qubit operator in first- or second-order Trotterized form.
     The algorithm is described in Whitfield 2010 https://arxiv.org/pdf/1001.3855.pdf
 
@@ -94,12 +94,20 @@ def get_exponentiated_qubit_operator_circuit(qubit_op, time=1., variational=Fals
         variational (bool) : Whether the coefficients are variational
         trotter_order (int): order of trotter approximation, only 1 or 2 are supported.
         return_phase (bool): Return the global-phase generated
+        pauli_order (list): The desired pauli_word order for trotterization defined as a list of (pauli_word, coeff)
+            elements which have matching dictionary elements pauli_word: coeff in QubitOperator terms.items().
+            The coeff in pauli_order is used to generate the exponential.
 
     Returns:
         Circuit: circuit corresponding to exponentiation of qubit operator
         phase : The global phase of the time evolution if return_phase=True else not included
     """
-    pauli_words = list(qubit_op.terms.items())
+    if pauli_order is None:
+        pauli_words = list(qubit_op.terms.items())
+    elif isinstance(pauli_order, list):
+        pauli_words = pauli_order.copy()
+    else:
+        raise ValueError("ordered terms must be a list with elements (keys, values) of qubit_op.terms.items()")
 
     if trotter_order > 2:
         raise ValueError(f"Trotter order of >2 is not supported currently in Tangelo.")
@@ -118,7 +126,7 @@ def get_exponentiated_qubit_operator_circuit(qubit_op, time=1., variational=Fals
     phase = 1.
     exp_pauli_word_gates = list()
     for i in range(trotter_order):
-        if i == 0:
+        if i == 1:
             pauli_words.reverse()
         for pauli_word, coef in pauli_words:
             if pauli_word:  # identity terms do not contribute to evolution outside of a phase

tangelo/toolboxes/ansatz_generator/tests/data/mol_H4_doublecation_minao_init_qubitham_jw_b.data

@@ -0,0 +1,18 @@
+QubitOperator:
+(-3.201203136341336+0j) [] +
+(0.018922220448748025+0j) [X0 X1] +
+(0.018922220448748025+0j) [Y0 Y1] +
+(0.6887270305253504+0j) [Z0] +
+(0.37691668685924784+0j) [Z1] +
+(-0.02281117974146273+0j) [X2 X3] +
+(-0.02281117974146273+0j) [Y2 Y3] +
+(0.3753113309246301+0j) [Z2] +
+(0.15964651986143952+0j) [Z3] +
+(0.018922220448748025+0j) [X4 X5] +
+(0.018922220448748025+0j) [Y4 Y5] +
+(0.6887270305253504+0j) [Z4] +
+(0.37691668685924784+0j) [Z5] +
+(-0.02281117974146273+0j) [X6 X7] +
+(-0.02281117974146273+0j) [Y6 Y7] +
+(0.3753113309246301+0j) [Z6] +
+(0.15964651986143952+0j) [Z7]

tangelo/toolboxes/ansatz_generator/tests/data/mol_H4_doublecation_minao_qubitham_jw_b.data

@@ -0,0 +1,186 @@
+QubitOperator:
+(-0.845088084959612+0j) [] +
+(-0.0020776113200212075+0j) [X0 X1] +
+(-0.011761015389060145+0j) [X0 X1 X2 X3] +
+(-0.0003365342989052316+0j) [X0 X1 Y2 Y3] +
+(0.002844217831601514+0j) [X0 X1 Z2] +
+(0.005067140284950715+0j) [X0 X1 Z3] +
+(0.02660445410908035+0j) [X0 X1 X4 X5] +
+(0.02660445410908035+0j) [X0 X1 Y4 Y5] +
+(0.009461086978084416+0j) [X0 X1 Z4] +
+(-0.002045316086697597+0j) [X0 X1 Z5] +
+(-0.024395190370696845+0j) [X0 X1 X6 X7] +
+(-0.024395190370696845+0j) [X0 X1 Y6 Y7] +
+(-0.007801932778402895+0j) [X0 X1 Z6] +
+(0.013474635539233077+0j) [X0 X1 Z7] +
+(-0.011424481090154913+0j) [X0 Y1 Y2 X3] +
+(0.024934767638066777+0j) [X0 Z1 X2 X4 Z5 X6] +
+(0.006238164536781785+0j) [X0 Z1 X2 X4 Z5 Z6 X7] +
+(0.024934767638066777+0j) [X0 Z1 X2 Y4 Z5 Y6] +
+(0.006238164536781785+0j) [X0 Z1 X2 Y4 Z5 Z6 Y7] +
+(0.01064615061000441+0j) [X0 Z1 X2 X5 X6] +
+(-0.02405865607179162+0j) [X0 Z1 X2 X5 Z6 X7] +
+(0.01064615061000441+0j) [X0 Z1 X2 Y5 Y6] +
+(-0.02405865607179162+0j) [X0 Z1 X2 Y5 Z6 Y7] +
+(0.006238164536781785+0j) [X0 Z1 Z2 X3 X4 Z5 X6] +
+(0.017676042848046+0j) [X0 Z1 Z2 X3 X4 Z5 Z6 X7] +
+(0.006238164536781785+0j) [X0 Z1 Z2 X3 Y4 Z5 Y6] +
+(0.017676042848046+0j) [X0 Z1 Z2 X3 Y4 Z5 Z6 Y7] +
+(-0.012634174981636702+0j) [X0 Z1 Z2 X3 X5 X6] +
+(-0.008407495254282365+0j) [X0 Z1 Z2 X3 X5 Z6 X7] +
+(-0.012634174981636702+0j) [X0 Z1 Z2 X3 Y5 Y6] +
+(-0.008407495254282365+0j) [X0 Z1 Z2 X3 Y5 Z6 Y7] +
+(-0.011424481090154913+0j) [Y0 X1 X2 Y3] +
+(-0.0020776113200212075+0j) [Y0 Y1] +
+(-0.0003365342989052316+0j) [Y0 Y1 X2 X3] +
+(-0.011761015389060145+0j) [Y0 Y1 Y2 Y3] +
+(0.002844217831601514+0j) [Y0 Y1 Z2] +
+(0.005067140284950715+0j) [Y0 Y1 Z3] +
+(0.02660445410908035+0j) [Y0 Y1 X4 X5] +
+(0.02660445410908035+0j) [Y0 Y1 Y4 Y5] +
+(0.009461086978084416+0j) [Y0 Y1 Z4] +
+(-0.002045316086697597+0j) [Y0 Y1 Z5] +
+(-0.024395190370696845+0j) [Y0 Y1 X6 X7] +
+(-0.024395190370696845+0j) [Y0 Y1 Y6 Y7] +
+(-0.007801932778402895+0j) [Y0 Y1 Z6] +
+(0.013474635539233077+0j) [Y0 Y1 Z7] +
+(0.024934767638066777+0j) [Y0 Z1 Y2 X4 Z5 X6] +
+(0.006238164536781785+0j) [Y0 Z1 Y2 X4 Z5 Z6 X7] +
+(0.024934767638066777+0j) [Y0 Z1 Y2 Y4 Z5 Y6] +
+(0.006238164536781785+0j) [Y0 Z1 Y2 Y4 Z5 Z6 Y7] +
+(0.01064615061000441+0j) [Y0 Z1 Y2 X5 X6] +
+(-0.02405865607179162+0j) [Y0 Z1 Y2 X5 Z6 X7] +
+(0.01064615061000441+0j) [Y0 Z1 Y2 Y5 Y6] +
+(-0.02405865607179162+0j) [Y0 Z1 Y2 Y5 Z6 Y7] +
+(0.006238164536781785+0j) [Y0 Z1 Z2 Y3 X4 Z5 X6] +
+(0.017676042848046+0j) [Y0 Z1 Z2 Y3 X4 Z5 Z6 X7] +
+(0.006238164536781785+0j) [Y0 Z1 Z2 Y3 Y4 Z5 Y6] +
+(0.017676042848046+0j) [Y0 Z1 Z2 Y3 Y4 Z5 Z6 Y7] +
+(-0.012634174981636702+0j) [Y0 Z1 Z2 Y3 X5 X6] +
+(-0.008407495254282365+0j) [Y0 Z1 Z2 Y3 X5 Z6 X7] +
+(-0.012634174981636702+0j) [Y0 Z1 Z2 Y3 Y5 Y6] +
+(-0.008407495254282365+0j) [Y0 Z1 Z2 Y3 Y5 Z6 Y7] +
+(0.23477912416223978+0j) [Z0] +
+(0.07755867751288839+0j) [Z0 Z1] +
+(-0.0025837417313018998+0j) [Z0 X2 X3] +
+(-0.0025837417313018998+0j) [Z0 Y2 Y3] +
+(0.07733247653566544+0j) [Z0 Z2] +
+(0.09333330628587891+0j) [Z0 Z3] +
+(0.009461086978084416+0j) [Z0 X4 X5] +
+(0.009461086978084416+0j) [Z0 Y4 Y5] +
+(0.11171627890094822+0j) [Z0 Z4] +
+(0.10416313162196875+0j) [Z0 Z5] +
+(-0.008821906268083685+0j) [Z0 X6 X7] +
+(-0.008821906268083685+0j) [Z0 Y6 Y7] +
+(0.10226724417373223+0j) [Z0 Z6] +
+(0.1110093491339249+0j) [Z0 Z7] +
+(0.010646150610004408+0j) [X1 X2 X4 Z5 X6] +
+(-0.012634174981636702+0j) [X1 X2 X4 Z5 Z6 X7] +
+(0.010646150610004408+0j) [X1 X2 Y4 Z5 Y6] +
+(-0.012634174981636702+0j) [X1 X2 Y4 Z5 Z6 Y7] +
+(0.01934883030685017+0j) [X1 X2 X5 X6] +
+(-0.008901638567159004+0j) [X1 X2 X5 Z6 X7] +
+(0.01934883030685017+0j) [X1 X2 Y5 Y6] +
+(-0.008901638567159004+0j) [X1 X2 Y5 Z6 Y7] +
+(-0.02405865607179162+0j) [X1 Z2 X3 X4 Z5 X6] +
+(-0.008407495254282365+0j) [X1 Z2 X3 X4 Z5 Z6 X7] +
+(-0.02405865607179162+0j) [X1 Z2 X3 Y4 Z5 Y6] +
+(-0.008407495254282365+0j) [X1 Z2 X3 Y4 Z5 Z6 Y7] +
+(-0.008901638567159004+0j) [X1 Z2 X3 X5 X6] +
+(0.02661467635818076+0j) [X1 Z2 X3 X5 Z6 X7] +
+(-0.008901638567159004+0j) [X1 Z2 X3 Y5 Y6] +
+(0.02661467635818076+0j) [X1 Z2 X3 Y5 Z6 Y7] +
+(0.010646150610004408+0j) [Y1 Y2 X4 Z5 X6] +
+(-0.012634174981636702+0j) [Y1 Y2 X4 Z5 Z6 X7] +
+(0.010646150610004408+0j) [Y1 Y2 Y4 Z5 Y6] +
+(-0.012634174981636702+0j) [Y1 Y2 Y4 Z5 Z6 Y7] +
+(0.01934883030685017+0j) [Y1 Y2 X5 X6] +
+(-0.008901638567159004+0j) [Y1 Y2 X5 Z6 X7] +
+(0.01934883030685017+0j) [Y1 Y2 Y5 Y6] +
+(-0.008901638567159004+0j) [Y1 Y2 Y5 Z6 Y7] +
+(-0.02405865607179162+0j) [Y1 Z2 Y3 X4 Z5 X6] +
+(-0.008407495254282365+0j) [Y1 Z2 Y3 X4 Z5 Z6 X7] +
+(-0.02405865607179162+0j) [Y1 Z2 Y3 Y4 Z5 Y6] +
+(-0.008407495254282365+0j) [Y1 Z2 Y3 Y4 Z5 Z6 Y7] +
+(-0.008901638567159004+0j) [Y1 Z2 Y3 X5 X6] +
+(0.02661467635818076+0j) [Y1 Z2 Y3 X5 Z6 X7] +
+(-0.008901638567159004+0j) [Y1 Z2 Y3 Y5 Y6] +
+(0.02661467635818076+0j) [Y1 Z2 Y3 Y5 Z6 Y7] +
+(0.07873792608304384+0j) [Z1] +
+(-0.00523830590529105+0j) [Z1 X2 X3] +
+(-0.00523830590529105+0j) [Z1 Y2 Y3] +
+(0.08417436673290517+0j) [Z1 Z2] +
+(0.07928157442541509+0j) [Z1 Z3] +
+(-0.002045316086697597+0j) [Z1 X4 X5] +
+(-0.002045316086697597+0j) [Z1 Y4 Y5] +
+(0.10416313162196875+0j) [Z1 Z4] +
+(0.10702518092938991+0j) [Z1 Z5] +
+(0.0036633326618679546+0j) [Z1 X6 X7] +
+(0.0036633326618679546+0j) [Z1 Y6 Y7] +
+(0.10352319703975532+0j) [Z1 Z6] +
+(0.10589625078359582+0j) [Z1 Z7] +
+(-0.004483252597706383+0j) [X2 X3] +
+(-0.024395190370696845+0j) [X2 X3 X4 X5] +
+(-0.024395190370696845+0j) [X2 X3 Y4 Y5] +
+(-0.008821906268083685+0j) [X2 X3 Z4] +
+(0.0036633326618679546+0j) [X2 X3 Z5] +
+(0.025689949571830042+0j) [X2 X3 X6 X7] +
+(0.025689949571830042+0j) [X2 X3 Y6 Y7] +
+(0.007649625311503733+0j) [X2 X3 Z6] +
+(-0.012996931212451403+0j) [X2 X3 Z7] +
+(-0.004483252597706383+0j) [Y2 Y3] +
+(-0.024395190370696845+0j) [Y2 Y3 X4 X5] +
+(-0.024395190370696845+0j) [Y2 Y3 Y4 Y5] +
+(-0.008821906268083685+0j) [Y2 Y3 Z4] +
+(0.0036633326618679546+0j) [Y2 Y3 Z5] +
+(0.025689949571830042+0j) [Y2 Y3 X6 X7] +
+(0.025689949571830042+0j) [Y2 Y3 Y6 Y7] +
+(0.007649625311503733+0j) [Y2 Y3 Z6] +
+(-0.012996931212451403+0j) [Y2 Y3 Z7] +
+(0.07666866090982398+0j) [Z2] +
+(0.07784794028451397+0j) [Z2 Z3] +
+(-0.007801932778402895+0j) [Z2 X4 X5] +
+(-0.007801932778402895+0j) [Z2 Y4 Y5] +
+(0.10226724417373223+0j) [Z2 Z4] +
+(0.10352319703975532+0j) [Z2 Z5] +
+(0.007649625311503733+0j) [Z2 X6 X7] +
+(0.007649625311503733+0j) [Z2 Y6 Y7] +
+(0.1091589968106852+0j) [Z2 Z6] +
+(0.10353788985634402+0j) [Z2 Z7] +
+(-0.12227609382406271+0j) [Z3] +
+(0.013474635539233077+0j) [Z3 X4 X5] +
+(0.013474635539233077+0j) [Z3 Y4 Y5] +
+(0.1110093491339249+0j) [Z3 Z4] +
+(0.10589625078359582+0j) [Z3 Z5] +
+(-0.012996931212451403+0j) [Z3 X6 X7] +
+(-0.012996931212451403+0j) [Z3 Y6 Y7] +
+(0.10353788985634402+0j) [Z3 Z6] +
+(0.11970161375543707+0j) [Z3 Z7] +
+(-0.0020776113200212066+0j) [X4 X5] +
+(-0.011761015389060145+0j) [X4 X5 X6 X7] +
+(-0.0003365342989052316+0j) [X4 X5 Y6 Y7] +
+(0.002844217831601514+0j) [X4 X5 Z6] +
+(0.005067140284950715+0j) [X4 X5 Z7] +
+(-0.011424481090154913+0j) [X4 Y5 Y6 X7] +
+(-0.011424481090154913+0j) [Y4 X5 X6 Y7] +
+(-0.0020776113200212066+0j) [Y4 Y5] +
+(-0.0003365342989052316+0j) [Y4 Y5 X6 X7] +
+(-0.011761015389060145+0j) [Y4 Y5 Y6 Y7] +
+(0.002844217831601514+0j) [Y4 Y5 Z6] +
+(0.005067140284950715+0j) [Y4 Y5 Z7] +
+(0.23477912416223978+0j) [Z4] +
+(0.07755867751288839+0j) [Z4 Z5] +
+(-0.0025837417313018998+0j) [Z4 X6 X7] +
+(-0.0025837417313018998+0j) [Z4 Y6 Y7] +
+(0.07733247653566544+0j) [Z4 Z6] +
+(0.09333330628587891+0j) [Z4 Z7] +
+(0.07873792608304378+0j) [Z5] +
+(-0.00523830590529105+0j) [Z5 X6 X7] +
+(-0.00523830590529105+0j) [Z5 Y6 Y7] +
+(0.08417436673290517+0j) [Z5 Z6] +
+(0.07928157442541509+0j) [Z5 Z7] +
+(-0.004483252597706375+0j) [X6 X7] +
+(-0.004483252597706375+0j) [Y6 Y7] +
+(0.07666866090982404+0j) [Z6] +
+(0.07784794028451397+0j) [Z6 Z7] +
+(-0.12227609382406274+0j) [Z7]