Update intro_workshop_exercises.ipynb

docs/tutorials/intro_workshop_exercises.ipynb

@@ -122,7 +122,7 @@
     "operator*, and we refer to creation and annihilation operators as\n",
     "fermionic *ladder operators*.\n",
     "    \n",
-    "The canonical anticommutation relations impose a number of consequences on the structure of the vector space on which the ladder operators act; see [Michael Nielsen's notes](http://michaelnielsen.org/blog/archive/notes/fermions_and_jordan_wigner.pdf) for a good discussion.\n",
+    "The canonical anticommutation relations impose a number of consequences on the structure of the vector space on which the ladder operators act; see [Michael Nielsen's notes](https://futureofmatter.com/assets/fermions_and_jordan_wigner.pdf) for a good discussion.\n",
     "\n",
     "The electronic structure Hamiltonian is commonly written in the form\n",
     "$$\n",