v0.4.0

Features

• Ability to support additional result types for gate model devices
  • The following result types are supported:
    • State vector
    • Amplitude
    • Probability
    • Expectation
    • Variance
    • Sample
  • examples/bell_result_types.py has example usage
  • When shots>0, users can request probability in the computational basis, sampling, expectation, variance, and sampling for the desired observable.
    • These values are calculated from measurements.
  • When shots=0 for simulators, users can request state vector and amplitude, as well as exact values for expectation, variance, and sampling for the desired observable.
    • Sample is not supported when shots=0
    • measurements, measurement_counts, and measurement_probabilitiesare not returned in the task result when shots=0
• Ability to check version in Python
• Increased default polling timeout for AWS devices to 5 days
• Added topology_graph as an attribute of AwsQpu that returns the topology of the QPU as a networkx graph

Breaking Changes

• When using AwsQuantumSimulator and LocalSimulator, shots is by default 0
• As part of new result types feature, .state_vector of a GateModelQuantumTaskResult is only returned when state vector is requested as a result type and shots=0
• Corrected Ising coupling gate matrix definitions using reference https://arxiv.org/abs/1707.06356.
• BraketSimulator has been moved to amazon-braket-default-simulator-python

Documentation Changes

• API documentation for new result types feature
• Updates to README and example scripts in /examples folder