Add a backend for IonQ.

README.rst

@@ -13,7 +13,7 @@ ProjectQ - An open source software framework for quantum computing
 
 .. image:: https://badge.fury.io/py/projectq.svg
     :target: https://badge.fury.io/py/projectq
-    
+
 .. image:: https://img.shields.io/badge/python-2.7%2C%203.4%2C%203.5%2C%203.6-brightgreen.svg
 
 
@@ -24,7 +24,7 @@ targeting various types of hardware, a high-performance quantum computer
 simulator with emulation capabilities, and various compiler plug-ins.
 This allows users to
 
--  run quantum programs on the IBM Quantum Experience chip, AQT devices or AWS Braket service provided devices
+-  run quantum programs on the IBM Quantum Experience chip, AQT devices, AWS Braket, or IonQ service provided devices
 -  simulate quantum programs on classical computers
 -  emulate quantum programs at a higher level of abstraction (e.g.,
    mimicking the action of large oracles instead of compiling them to
@@ -108,7 +108,7 @@ To run a program on the IBM Quantum Experience chips, all one has to do is choos
 
     import projectq.setups.ibm
     from projectq.backends import IBMBackend
-    
+
     token='MY_TOKEN'
     device='ibmq_16_melbourne'
     compiler_engines = projectq.setups.ibm.get_engine_list(token=token,device=device)
@@ -125,7 +125,7 @@ To run a program on the AQT trapped ion quantum computer, choose the `AQTBackend
 
     import projectq.setups.aqt
     from projectq.backends import AQTBackend
-    
+
     token='MY_TOKEN'
     device='aqt_device'
     compiler_engines = projectq.setups.aqt.get_engine_list(token=token,device=device)
@@ -172,6 +172,37 @@ IonQ from IonQ and the state vector simulator SV1:
        python3 -m pip install -ve .[braket]
 
 
+**Running a quantum program on IonQ devices**
+
+To run a program on the IonQ trapped ion hardware, use the `IonQBackend` and its corresponding setup.
+
+Currently available devices are:
+
+* `ionq_simulator`: A 29-qubit simulator.
+* `ionq_qpu`: A 11-qubit trapped ion system.
+
+.. code-block:: python
+
+    import projectq.setups.ionq
+    from projectq import MainEngine
+    from projectq.backends import IonQBackend
+
+    token = 'MY_TOKEN'
+    device = 'ionq_qpu'
+    backend = IonQBackend(
+        token=token,
+        use_hardware=True,
+        num_runs=1024,
+        verbose=False,
+        device=device,
+    )
+    compiler_engines = projectq.setups.ionq.get_engine_list(
+        token=token,
+        device=device,
+    )
+    eng = MainEngine(backend, engine_list=compiler_engines)
+
+
 **Classically simulate a quantum program**
 
 ProjectQ has a high-performance simulator which allows simulating up to about 30 qubits on a regular laptop. See the `simulator tutorial <https://github.com/ProjectQ-Framework/ProjectQ/blob/feature/update-readme/examples/simulator_tutorial.ipynb>`__ for more information. Using the emulation features of our simulator (fast classical shortcuts), one can easily emulate Shor's algorithm for problem sizes for which a quantum computer would require above 50 qubits, see our `example codes <http://projectq.readthedocs.io/en/latest/examples.html#shor-s-algorithm-for-factoring>`__.
@@ -180,7 +211,7 @@ ProjectQ has a high-performance simulator which allows simulating up to about 30
 The advanced features of the simulator are also particularly useful to investigate algorithms for the simulation of quantum systems. For example, the simulator can evolve a quantum system in time (without Trotter errors) and it gives direct access to expectation values of Hamiltonians leading to extremely fast simulations of VQE type algorithms:
 
 .. code-block:: python
-    
+
     from projectq import MainEngine
     from projectq.ops import All, Measure, QubitOperator, TimeEvolution
 
@@ -225,7 +256,7 @@ When using ProjectQ for research projects, please cite
    `Quantum 2, 49 (2018) <https://doi.org/10.22331/q-2018-01-31-49>`__
    (published on `arXiv <https://arxiv.org/abs/1612.08091>`__ on 23 Dec 2016)
 -  Thomas Häner, Damian S. Steiger, Krysta M. Svore, and Matthias Troyer
-   "A Software Methodology for Compiling Quantum Programs" `Quantum Sci. Technol. 3 (2018) 020501 <https://doi.org/10.1088/2058-9565/aaa5cc>`__ 
+   "A Software Methodology for Compiling Quantum Programs" `Quantum Sci. Technol. 3 (2018) 020501 <https://doi.org/10.1088/2058-9565/aaa5cc>`__
    (published on `arXiv <http://arxiv.org/abs/1604.01401>`__ on 5 Apr 2016)
 
 Authors