OpenFermion v0.2

Second production release. Adds significant functionality including (but not limited to):

• Generalizes the InteractionTensor class to handle arbitrary marginals. Now called PolynomialTensor.
• Adds a data structure for manipulating quadratic Hamiltonians called QuadraticHamiltonian.
• Adds code to prepare Slater determinants by Givens rotations.
• Adds code to obtain eigenstates of quadratic Hamiltonians and circuits to prepare them.
• Adds code to implement general n-body rotations of PolynomialTensor using np.einsum.
• Adds code to compute the BCH expansion of our operator types to arbitrary order.
• Adds code for simulating basic error channels including the depolarizing channel.
• Adds code for outputting fermionic circuit specifications as QASM strings.
• Minor bug fixes pertaining to conventions around Jordan-Wigner ordering and basis rotations.
• Minor bug fixes pertaining to the generating and storage of HDF5 MolecularData files.

OpenFermion v0.1

First production release! Improvements over previous alpha version includes:

• Updated Docker image.
• Updated README and docker installation instructions.
• Fixed a small bug in the mean-field D-Wave Hamiltonian generation.
• Moved unitary coupled cluster code back to OpenFermion.
• Added Hubbard model with particle-hole symmetry.

OpenFermion v0.1a4

• Updates molecular data structure to allow for use with abstract molecules.
• Fixes error in docker file and improves docker instructions.
• Some bug fixes for model Hamiltonians.
• Adds routine for mean-field state preparation circuits.

OpenFermion v0.1a3

• Rearranged repo to contain "hamiltonians" module (breaks older plugin versions).
• Added Docker image for robust installation.
• Added code for generating mean-field D-Wave Hamiltonians.
• Added code for preparing arbitrary Slater determinants via Givens' rotations.
• Many minor changes to documentation.

OpenFermion v0.1a1

• Added a large number of robust tests.
• Removed unnecessary library dependancies.
• Polished the readme and other documentation.
• Added code to generate N-Representability equality constraints.
• Added code to use N-Representability equality constraints to project Hamiltonians.

OpenFermion v0.1a0

The first alpha release of OpenFermion. Substantial changes from fork of FermiLib include removing explicit dependencies on ProjectQ and relocating the "circuits" module to a plugin, OpenFermion-ProjectQ.

Initial commit made on behalf of Ryan Babbush (Google), Jarrod McClean (Google), Ian Kivlichan (Harvard), Damian Steiger (ETH Zurich), Wei Sun (Google), Craig Gidney (Google), Thomas Haner (ETH Zurich), Hannah Sim (Harvard), Vojtech Havlicek (Oxford), Kanav Setia (Dartmouth), Nicholas Rubin (Rigetti), Matthew Neeley (Google) and Dave Bacon (Google).