Base Gaussian State dm doesn't preserve locality dimensions #726
Description
Before posting a bug report
- I have searched exisisting GitHub issues to make sure the issue does not already exist.
Expected behavior
BaseGaussianState.dm() doesn't preserve locality dimensions. The Fock basis backend and Gaussian backend should give the same results.
Actual behavior
state.dm() gives gives only 2 dimensional matricies. The Fock basis state gives a multi-index object depending on the number of modes.
Reproduces how often
Always
System information
>>> sf.about()
Strawberry Fields: a Python library for continuous-variable quantum circuits.
Copyright 2018-2020 Xanadu Quantum Technologies Inc.
Python version: 3.10.5
Platform info: Linux-5.18.12-arch1-1-x86_64-with-glibc2.35
Installation path: /home/lund/.local/lib/python3.10/site-packages/strawberryfields
Strawberry Fields version: 0.23.0
Numpy version: 1.22.4
Scipy version: 1.8.1
SymPy version: 1.10.1
NetworkX version: 2.8.5
The Walrus version: 0.19.0
Blackbird version: 0.4.0
XCC version: 0.2.1
TensorFlow version: NoneSource code
import strawberryfields as sf
import strawberryfields.ops as op
p = sf.Program(2)
with p.context as q:
op.Squeezed(1) | q[0]
e = sf.Engine('fock', backend_options={'cutoff_dim': 4})
r = e.run(p)
print(f"Fock engine density matrix shape {r.state.dm().shape}")
e = sf.Engine('gaussian')
r = e.run(p)
print(f"Gaussian engine density matrix shape {r.state.dm(cutoff=4).shape}")Tracebacks
No response
Additional information
No response