v7.1.0

Added

• Result.outcome_map, which returns a mapping from measurement outcomes to
  their frequencies and states.
• Extended gate support in piquasso.dual_rail_encoding.
• Support for Vacuum and Create in SamplingSimulator (previously one could
  only use StateVector for preparing initial states).
• Support for using expressions instead of lambda functions to specify conditions
  and runtime resolution of instruction parameters. Example:

  import numpy as np
  import piquasso as pq
  
  # Create a program with explicit instruction list.
  program = pq.Program(
      instructions=[
          # Prepare a superposition of three two-mode Fock states:
          # |0,2>, |1,1>, and |2,0>, each with equal amplitude.
          pq.StateVector([0, 2]) * np.sqrt(1 / 3),
          pq.StateVector([1, 1]) * np.sqrt(1 / 3),
          pq.StateVector([2, 0]) * np.sqrt(1 / 3),
          # Measure photon number on mode 1 (mid-circuit measurement).
          pq.ParticleNumberMeasurement().on_modes(1),
          # Apply an unresolved squeezing gate on mode 0.
          # The squeezing parameter r is determined *at runtime*
          # from the measurement outcome (x[-1] = last outcome value).
          pq.Squeezing(r="0.1 * x[-1] ** 2").on_modes(0),
      ]
  )
  
  # Run the program on a 2-mode Fock simulator for 10 random measurement shots.
  result = pq.PureFockSimulator(d=2).execute(program, shots=10)

• Support for exporting blackbird code through Program.to_blackbird_code and
  Program.save_as_blackbird_code.
• More extensive support for postselecting photon numbers in SamplingSimulator.

Fixed

• Inferring the number of modes from the instructions was faulty in the previous
  version (where it was introduced), but has been fixed in this version.
• How the Phaseshift gate is converted from Qiskit in the dual-rail encoding module.

Minor changes

• Instruction validation is moved to happen runtime, i.e., at Simulator.execute
  or Simulator.execute_instructions. With this, a more comprehensive
  differentiability support can be enabled. Also, it is not required to set
  validate=False in Config when the user wants to JIT-compile Piquasso code
  with JAX.
• In the dual_rail_encoding module, the representation of a qubit is changed.
  In the current version, a qubit $\ket{0}_{\text{qubit}}$ state is represented by
  $\ket{1,0}_{\text{qumode}}$, whereas previously it was $\ket{0,1}_{\text{qumode}}$.

Full Changelog: v7.0.0...v7.1.0