fix teleportation.py beamsplitter phase (to 0) (#674)

* fix teleportation.py beamsplitter phase (to 0)

The teleportation example fails to teleport the state. Setting the BS phase to 0 apparently fixes this for various numeric examples. The phase was 0 in the previous version of this example as well as the theory part of the html example in the docs.

* Update examples/teleportation.py

Co-authored-by: Theodor <theodor.isacsson@gmail.com>

* Update CHANGELOG.md

* Update .github/CHANGELOG.md

Co-authored-by: Theodor <theodor.isacsson@gmail.com>

Co-authored-by: Theodor <theodor.isacsson@gmail.com>

.github/CHANGELOG.md

@@ -14,14 +14,17 @@
   circuit layout. Without a layout, the gate parameters cannot be validated against the device
   specification.
   [(#661)](https://github.com/XanaduAI/strawberryfields/pull/661)
+
+* The teleportation tutorial `examples/teleportation.py` now uses the correct value (now `phi = 0` instead of `phi = np.pi / 2`) for the phase shift of the beamsplitters.
+  [(#674)](https://github.com/XanaduAI/strawberryfields/pull/674)
 
 <h3>Documentation</h3>
 
 <h3>Contributors</h3>
 
 This release contains contributions from (in alphabetical order):
 
-Theodor Isacsson
+Theodor Isacsson, Jon Schlipf
 
 # Release 0.21.0 (current release)
 

examples/teleportation.py

@@ -29,7 +29,7 @@
     Squeezed(2) | q[2]
 
     # apply gates
-    BS = BSgate(pi / 4, pi)
+    BS = BSgate(pi / 4, 0)
     BS | (q[1], q[2])
     BS | (q[0], q[1])