Qibo

Major New Features

- Collapse gate.
- Shor (2n+3) example.
- qPDF model and example.
- Density matrix simulation using custom operators.
- Post-measurement bit-flip errors.
- Thermal relaxation error channel.
- Parallel optimization using multiprocessing for L-BFGS-B on CPU.
- Improved performance when repeating circuit execution.
- Replacing TensorFlow ThreadPool with OpenMP for custom operators on CPU.
- General code upgrades including tests, wheels and documentation.

Fixes
- Cost function for autoencoder tutorial.
- Circuit depth calculation.
- Backend return name.
- Trotter Hamiltonian from_symbolic and make_compatible.
- Scipy missing requirement in pip package.

Major Features
- Implemented new entaglement spectrum callback
- Extended circuit summary, fixed circuit depth definition.
- New method for circuit inversion
- New general unitary gates.
- Updating QASM and testing its compatibility.
- Adding possibility to add circuits to larger ones.
- Including symbolic interface for Hamiltonian allocation.
- Upgraded TensorFlow pip dependency to 2.3.1
- Updated documentation, fixed typos.
- Adjusting documentation urls to stable.

First Qibo stable release.

Major Features
- Basic circuit model containing gates and/or measurements (Circuit).
- Circuits that can be executed on multiple devices such as CPU/GPUs (DistributedCircuit).
- Circuit implementing the Quantum Fourier Transform (QFT).
- Variational Quantum Eigensolver (VQE), with support for optimization of the variational parameters.
- Quantum Approximate Optimization Algorithm (QAOA), with support for optimization of the variation parameters.
- Unitary time evolution of quantum states under a Hamiltonian (StateEvolution).
- Adiabatic time evolution of quantum states, with support for optimization of the scheduling function (AdiabaticEvolution).

Documentation cleanup, further optimization.

Pre-release for testing.

Pre-release for testing.
- adiabatic evolution algorithms
- code optimization and acceleration
- advanced tutorials and examples
- linux wheels are compiled with CUDA 10.1 and manylinux2010 support.