def get_amplitudes(
self,
circuit: Circuit,
states: List[str],
valid_check: bool = True,
**kwargs: KwargTypes,
) -> Dict[str, complex]:
"""
Compute the complex coefficients of the final state.
Supported `kwargs` are as for `BraketBackend.process_circuits`.
:param states: classical states of interest, as binary strings of '0' and '1'
:returns: final complex amplitudes if initial state is all-zeros
"""
if not self.supports_amplitude:
raise RuntimeError("Backend does not support amplitude")
if valid_check:
self._check_all_circuits([circuit], nomeasure_warn=False)
bkcirc = self._to_bkcirc(circuit)
restype = ResultType.Amplitude(states)
bkcirc.add_result_type(restype)
task = self._run(bkcirc, n_shots=0, **kwargs)
res = task.result()
amplitudes = res.get_value_by_result_type(restype)
cdict = {}
for k, v in amplitudes.items():
# The amazon/sv1 simulator gives us 2-element lists [re, im].
# The local simulator gives us numpy.complex128.
cdict[k] = complex(*v) if type(v) is list else complex(v)
return cdict
def amplitude(state: List[str]) -> ResultType:
"""Registers this function into the circuit class.
Args:
state (List[str]): list of quantum states as strings with "0" and "1"
Returns:
ResultType: state vector as a requested result type
Examples:
>>> circ = Circuit().amplitude(state=["01", "10"])
"""
return ResultType.Amplitude(state=state)