Update ansatz.ipynb to fix gate name

learning/courses/quantum-chem-with-vqe/ansatz.ipynb

@@ -45,7 +45,7 @@
     "\n",
     "An `efficient_su_2` circuit consists of layers of single qubit operations spanned by SU(2) (special unity group of degree 2, like Pauli rotation gates) and CX entanglements. This is a heuristic pattern that can be useful in variational quantum algorithms like VQE and classification circuits in quantum machine learning (QML).\n",
     "\n",
-    "We'll start with a four-qubit example `efficient_su2` circuit with two types of SU(2) gates, say rx and ry. We also specify an entanglement scheme and the number of repetitions. If you simply `.draw()` the circuits, you will get a fairly abstract representation. A more comprehensible circuit diagram is obtained by using `.decompose().draw()`, and here we will use `output = \"mpl\"'."
+    "We'll start with a four-qubit example `efficient_su2` circuit with two types of SU(2) gates, say rx and y. We also specify an entanglement scheme and the number of repetitions. If you simply `.draw()` the circuits, you will get a fairly abstract representation. A more comprehensible circuit diagram is obtained by using `.decompose().draw()`, and here we will use `output = \"mpl\"'."
    ]
   },
   {