quimb-1.2.0

Enhancements

• Added kraus_op for general, noisy quantum operations

• Added projector for constructing projectors from observables

• Added measure for measuring and collapsing quantum states

• Added cprint pretty printing states in computational basis

• Added simulate_counts for simulating computational basis counts

• TN: Add TensorNetwork.rank_simplify

• TN: Add TensorNetwork.isel

• TN: Add TensorNetwork.cut_iter

• TN: Add 'split-gate' gate mode

• TN: Add optimize_tensorflow.TNOptimizer for tensorflow based optimization
  of arbitrary, contstrained tensor networks.

• TN: Add Dense1D.rand

• TN: Add tensor_core.connect to conveniently set a shared index for tensors

• TN: make many more tensor operations agnostic of the array backend (e.g. numpy, cupy,
  tensorflow, ...)

• TN: allow tensor_1d.align_TN_1D to take an MPO as the first argument

• TN: add SpinHam.build_sparse

• TN: add Tensor.unitize and TensorNetwork.unitize to impose unitary/isometric constraints on tensors specified using the left_inds kwarg

• Many updates to tensor network quantum circuit simulation including:

  • CircuitMPS
  • CircuitDense
  • 49-qubit depth 30 circuit simulation example https://quimb.readthedocs.io/en/latest/examples/ex_quantum_circuit.html

• Add from quimb.gates import * as shortcut to import X, Z, CNOT, ....

• Add U_gate for parametrized arbitrary single qubit unitary

Bug fixes:

• Fix pkron for case len(dims) == len(inds) (#17, #18).
• Fix qarray printing for older numpy versions
• Fix TN quantum circuit bug where Z and X rotations were swapped
• Fix variable bond MPO building (#22) and L=2 DMRG
• Fix norm(X, 'trace') for non-hermitian matrices
• Add autoray as dependency (#21)