"Istropic" -> "Isotrophic" typo fix

labs/lab4/lab4.ipynb

@@ -24,7 +24,7 @@
     "Here $N$ is the number of sites in our chain and $X_i$, $Y_i$, and $Z_i$ are the Pauli operators which act on the $i^{th}$ site. The parameters $J_x$, $J_y$, and $J_z$, represent the coupling strength for the Coulomb ($J_x$ and $J_y$) and Ising ($J_z$) interaction. For the rest of the lab we'll consider $J=J_x=J_y=1$ for simplicity. \n",
     "\n",
     "In general this model has a few phases based on the ratio $\\Delta = J_z/J$ (also known as the anisotropy). In this lab we will explore two of them:\n",
-    "- The **istropic** phase where $\\Delta = 1$. This is also known as the **XXX** phase.\n",
+    "- The **isotropic** phase where $\\Delta = 1$. This is also known as the **XXX** phase.\n",
     "- The **anisotropic** phase when $\\Delta \\neq 1$.\n",
     "\n",
     "To measure some interesting dynamics of this system, we will also introduce a transverse magnetic field with a strength $h$ which will interact with each site through the Pauli $X$ operator. The Hamiltonian of our spin chain will now take the form:\n",