I'm running a QPE algorithm on the amazon-braket but it can only apply on a 22 or 44 matrix, when I want to expand it into a 5*5 or more, it will come an error. As I know, there is no theoretical limitation on the size of matrix QPE can solve.
Here is the main part of the code:
def get_qpe_phases(measurement_counts, precision_qubits, items_to_keep=1):
bitstrings_precision_register = [
substring(key, precision_qubits) for key in measurement_counts.keys()
]
bitstrings_precision_register_set = set(bitstrings_precision_register)
bitstrings_precision_register_list = list(bitstrings_precision_register_set)
precision_results_dic = {key: 0 for key in bitstrings_precision_register_list}
for key in measurement_counts.keys():
counts = measurement_counts[key]
count_key = substring(key, precision_qubits)
precision_results_dic[count_key] += counts
c = Counter(precision_results_dic)
topmost = c.most_common(items_to_keep)
phases_decimal = [binaryToDecimal(item[0]) for item in topmost]
return phases_decimal, precision_results_dic
def run_qpe(
unitary,
precision_qubits,
query_qubits,
query_circuit,
items_to_keep=1,
shots=1000
):
circ = query_circuit
circ.qpe(precision_qubits, query_qubits, unitary, control_unitary=False)
# Add desired results_types
number_precision_qubits = len(precision_qubits)
num_qubits = len(precision_qubits)
circ.probability(np.array(precision_qubits))
device = LocalSimulator()
task=device.run(circ,shots=shots)
result=task.result()
metadata = result.task_metadata
probs_values = result.values[0]
measurements = result.measurements
measured_qubits = result.measured_qubits
measurement_counts = result.measurement_counts
measurement_probabilities = result.measurement_probabilities
format_bitstring = "{0:0" + str(num_qubits) + "b}"
bitstring_keys = [format_bitstring.format(ii) for ii in range(2 ** num_qubits)]
phases_decimal, precision_results_dic = get_qpe_phases(
measurement_counts, precision_qubits, items_to_keep
)
print('\nPhases:',phases_decimal)
eigenvalues = [np.exp(2 * np.pi * 1j * phase) for phase in phases_decimal]
# aggregate results
out = {
"circuit": circ,
"task_metadata": metadata,
"measurements": measurements,
"measured_qubits": measured_qubits,
"measurement_counts": measurement_counts,
"measurement_probabilities": measurement_probabilities,
"probs_values": probs_values,
"bitstring_keys": bitstring_keys,
"precision_results_dic": precision_results_dic,
"phases_decimal": phases_decimal,
"eigenvalues": eigenvalues,
}
return out
And when it comes to a 6*6 matrix,
from scipy.stats import unitary_group
import numpy as np
np.random.seed(seed=3000)
unitary1 = unitary_group.rvs(6)
result = estimate_phase(4,unitary1,5,printcir=False)
the error report is like:
---------------------------------------------------------------------------
ValueError Traceback (most recent call last)
<ipython-input-21-4eae0beac402> in <module>
4
5 unitary = unitary_group.rvs(6)
----> 6 result = estimate_phase(4,unitary,5,printcir=False)
<ipython-input-9-30dffae9e6c6> in estimate_phase(n, unitary, runit, shots, printcir)
15 query = Circuit().h(query_qubits)
16
---> 17 result = run_qpe(unitary, precision_qubits, query_qubits, query, items_to_keep=elen, shots = shots)
18 qeigvals= postprocess_qpe_results(result,printcir)
19
<ipython-input-6-1875e0e5a610> in run_qpe(unitary, precision_qubits, query_qubits, query_circuit, items_to_keep, shots)
92 ):
93 circ = query_circuit
---> 94 circ.qpe(precision_qubits, query_qubits, unitary, control_unitary=False)
95
96 # Add desired results_types
~/anaconda3/envs/Braket/lib/python3.7/site-packages/braket/circuits/circuit.py in method_from_subroutine(self, *args, **kwargs)
75
76 def method_from_subroutine(self, *args, **kwargs) -> SubroutineReturn:
---> 77 return self.add(func, *args, **kwargs)
78
79 function_name = func.__name__
~/anaconda3/envs/Braket/lib/python3.7/site-packages/braket/circuits/circuit.py in add(self, addable, *args, **kwargs)
495 self.add_circuit(item, *args, **kwargs)
496 elif callable(item):
--> 497 self.add(item(*args, **kwargs))
498 else:
499 raise TypeError(f"Cannot add a '{type(item)}' to a Circuit")
<ipython-input-6-1875e0e5a610> in qpe(precision_qubits, query_qubits, unitary, control_unitary)
39 else:
40 for _ in range(2 ** power):
---> 41 qpe_circ.controlled_unitary(qubit, query_qubits, unitary)
42 qpe_circ.inverse_qft(precision_qubits)
43
~/anaconda3/envs/Braket/lib/python3.7/site-packages/braket/circuits/circuit.py in method_from_subroutine(self, *args, **kwargs)
75
76 def method_from_subroutine(self, *args, **kwargs) -> SubroutineReturn:
---> 77 return self.add(func, *args, **kwargs)
78
79 function_name = func.__name__
~/anaconda3/envs/Braket/lib/python3.7/site-packages/braket/circuits/circuit.py in add(self, addable, *args, **kwargs)
495 self.add_circuit(item, *args, **kwargs)
496 elif callable(item):
--> 497 self.add(item(*args, **kwargs))
498 else:
499 raise TypeError(f"Cannot add a '{type(item)}' to a Circuit")
<ipython-input-6-1875e0e5a610> in controlled_unitary(control, target_qubits, unitary)
21 targets = [control] + target_qubits
22
---> 23 circ.unitary(matrix=controlled_matrix, targets=targets)
24
25 return circ
~/anaconda3/envs/Braket/lib/python3.7/site-packages/braket/circuits/circuit.py in method_from_subroutine(self, *args, **kwargs)
75
76 def method_from_subroutine(self, *args, **kwargs) -> SubroutineReturn:
---> 77 return self.add(func, *args, **kwargs)
78
79 function_name = func.__name__
~/anaconda3/envs/Braket/lib/python3.7/site-packages/braket/circuits/circuit.py in add(self, addable, *args, **kwargs)
495 self.add_circuit(item, *args, **kwargs)
496 elif callable(item):
--> 497 self.add(item(*args, **kwargs))
498 else:
499 raise TypeError(f"Cannot add a '{type(item)}' to a Circuit")
~/anaconda3/envs/Braket/lib/python3.7/site-packages/braket/circuits/gates.py in unitary(targets, matrix, display_name)
1339 """
1340 if 2 ** len(targets) != matrix.shape[0]:
-> 1341 raise ValueError("Dimensions of the supplied unitary are incompatible with the targets")
1342
1343 return Instruction(Gate.Unitary(matrix, display_name), target=targets)
ValueError: Dimensions of the supplied unitary are incompatible with the targets
So I'm wondering if it's the packages' problem or the program problem or any other had met the similar problem as I?
Thanks in advance!
