Koala is a quantum circuit/state simulator based on PEPS tensor networks.
NumPy and TensorBackends are required.
It is recommended to install Koala and TensorBackends in the editable (pip install -e
) mode, as they are currently under development.
git clone https://github.com/cyclops-community/tensorbackends.git
pip install -e ./tensorbackends
git clone https://github.com/LinjianMa/koala.git
pip install -e ./koala
Parallelization is provided by Cyclops Tensor Framework, and is optional.
python -m unittest
from koala import peps, Observable, Gate
# initialize a 2 by 3 state with peps approach and numpy backend
qstate = peps.computational_zeros(2, 3, backend='numpy')
# we also provide statevector approach and parallel backend
# statevector.computational_zeros(2, 3, backend='ctf')
# apply one gate or a list of gates
qstate.apply_gate(Gate('X', [], [0])) # (name, parameters, qubits)
qstate.apply_circuit([
Gate('R', [0.42], [2]),
Gate('CX', [], [1,4])
], threshold=None, maxrank=None)
# optional truncation threshold and rank for approximate simulation
# or apply arbitrary single site or local two-site operators
# qstate.apply_operator(np.array(...), [0])
# compute the amplitude, probability, and expectation value
qstate.amplitude([1,0,0,1,0,0])
qstate.probability([1,0,0,1,0,0])
observable = 1.5 * Observable.sum([
Observable.Z(0),
Observable.XY(3, 4) * 2
])
qstate.expectation(observable, use_cache=True) # optional caching