Pennylane-cirq

New features

* Added support for custom simulator objects for use with the Floq service.
[(51)](https://github.com/PennyLaneAI/pennylane-cirq/pull/51)

Contributors

This release contains contributions from (in alphabetical order):

Chase Roberts

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Improvements

* Added support for iSWAP and CPhase gate operations.
[(45)](https://github.com/PennyLaneAI/pennylane-cirq/pull/45)

Bug fixes

* Removed import of `qsimcirq` from `__init__.py`, allowing other devices in
this plugin to work without `qsimcirq` being installed.
[(46)](https://github.com/PennyLaneAI/pennylane-cirq/pull/46)

Contributors

This release contains contributions from (in alphabetical order):

Theodor Isacsson

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New features since last release

* PennyLane integration with the [qsim circuit simulator
package](https://github.com/quantumlib/qsim) is now available.
[(36)](https://github.com/PennyLaneAI/pennylane-cirq/pull/36).

The new devices include:

* `cirq.qsim`, a Schrödinger full state-vector simulator

* `cirq.qsimh`, a hybrid Schrödinger-Feynman simulator. This simulator cuts the qubit lattice into
two parts; each part is individually simulated using qsim, with Feynman-style path summation used
to return the final result. Compared to full state-vector simulation, qsimh reduces memory
requirements, at the expense of an increased runtime.

After installing the `qsimcirq` package, the qsim and qsimh devices
can be invoked via the names `"cirq.qsim"` and `"cirq.qsimh"` respectively, e.g.,

python
dev = qml.device("cirq.qsimh", qsimh_options=qsimh_options, wires=3)


These devices can then be used for the evaluation of QNodes within PennyLane. For more details,
see the [PennyLane qsim
documentation](https://pennylane-cirq.readthedocs.io/en/latest/devices/qsim.html)

Contributors

This release contains contributions from (in alphabetical order):

Theodor Isacsson, Nathan Killoran, Josh Izaac

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New features since last release

* Devices from Cirq's Pasqal submodule are now available for use.
[(40)](https://github.com/PennyLaneAI/pennylane-cirq/pull/40).

A simulator device compatible with Pasqal's neutral-atom model can be invoked via the name
`"cirq.pasqal"`, e.g.,

python
dev = qml.device("cirq.pasqal", control_radius=1.0, wires=3)


Contributors

This release contains contributions from (in alphabetical order):

Nathan Killoran, Josh Izaac

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New features

* Made plugin device compatible with new PennyLane wire management.
[(37)](https://github.com/PennyLaneAI/pennylane-cirq/pull/37)
[(42)](https://github.com/PennyLaneAI/pennylane-cirq/pull/42)

One can now specify any string or number as a custom wire label,
and use these labels to address subsystems on the device:

python
dev = qml.device('cirq.simulator', wires=['q1', 'ancilla', 0, 1])

def circuit():
qml.Hadamard(wires='q1')
qml.CNOT(wires=[1, 'ancilla'])
...


Contributors

This release contains contributions from (in alphabetical order):

Josh Izaac, Nathan Killoran, Maria Schuld

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Improvements

Contributors

This release contains contributions from (in alphabetical order):

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