diff --git a/.obsidian/workspace.json b/.obsidian/workspace.json
index 792a72f..3f8aba5 100644
--- a/.obsidian/workspace.json
+++ b/.obsidian/workspace.json
@@ -13,12 +13,12 @@
             "state": {
               "type": "markdown",
               "state": {
-                "file": "SS2026/Quantum Computing/7. Quantum Circuits/Quantum Circuits.md",
+                "file": "SS2026/Quantum Computing/8. Ket Notation/Ket Notation.md",
                 "mode": "source",
                 "source": false
               },
               "icon": "lucide-file",
-              "title": "Quantum Circuits"
+              "title": "Ket Notation"
             }
           }
         ]
@@ -216,13 +216,18 @@
   },
   "active": "25f5b25d5eca7203",
   "lastOpenFiles": [
+    "SS2026/Quantum Computing/8. Ket Notation/Anhänge/Pasted image 20260730101435.png",
+    "SS2026/Quantum Computing/8. Ket Notation/Anhänge/Pasted image 20260730101012.png",
+    "SS2026/Quantum Computing/8. Ket Notation/Anhänge",
+    "SS2026/Quantum Computing/Introduction to Quantum Computing.md",
+    "SS2026/Quantum Computing/8. Ket Notation/Ket Notation.md",
+    "SS2026/Quantum Computing/7. Quantum Circuits/Quantum Circuits.md",
+    "SS2026/Quantum Computing/8. Ket Notation",
     "SS2026/Quantum Computing/7. Quantum Circuits/Anhänge/Pasted image 20260730092817.png",
     "SS2026/Quantum Computing/7. Quantum Circuits/Anhänge/Pasted image 20260730092809.png",
     "SS2026/Quantum Computing/7. Quantum Circuits/Anhänge/Pasted image 20260730092802.png",
-    "SS2026/Quantum Computing/7. Quantum Circuits/Quantum Circuits.md",
     "SS2026/Quantum Computing/7. Quantum Circuits/Anhänge/Pasted image 20260730092648.png",
     "SS2026/Quantum Computing/7. Quantum Circuits/Anhänge/Pasted image 20260730092639.png",
-    "SS2026/Quantum Computing/Introduction to Quantum Computing.md",
     "SS2026/Quantum Computing/4. Observing and measuring/Observing probabilistic and measuring quantum systems.md",
     "SS2026/Quantum Computing/5. Partial observing and measuring/Partial observing and measuring systems.md",
     "SS2026/Quantum Computing/6. Composite Systems/Composite Systems.md",
@@ -232,7 +237,6 @@
     "SS2026/Quantum Computing/7. Quantum Circuits/Anhänge/Pasted image 20260730091827.png",
     "SS2026/Quantum Computing/7. Quantum Circuits/Anhänge",
     "SS2026/Quantum Computing/7. Quantum Circuits",
-    "SS2026/Quantum Computing/6. Composite Systems/Anhänge/Pasted image 20260729221523.png",
     "SS2026/Quantum Computing/6. Composite Systems/Anhänge",
     "SS2026/Quantum Computing/6. Composite Systems",
     "SS2026/Quantum Computing/5. Partial observing and measuring/Anhänge",
@@ -243,8 +247,6 @@
     "SS2026/Quantum Computing/Anhänge/Introduction-to-Quantum-Computing.pdf",
     "SS2026/Klausurplan.canvas",
     "SS2026/Quantum Computing/4. Observing and measuring/Anhänge",
-    "SS2026/Quantum Computing/4. Observing and measuring",
-    "SS2026/Quantum Computing/3. Quantum Systems/Anhänge",
     "SS2026/Datenbanken und Informationssysteme/4. SQL/SQL.md",
     "SS2026/Datenbanken und Informationssysteme/Datenbanken und Informationssysteme.md",
     "SS2026/Datenbanken und Informationssysteme/5. Relationale Anfragebearbeitung/Relationale Anfragebearbeitung.md",
@@ -260,7 +262,6 @@
     "SS2026/Datenbanken und Informationssysteme/4. SQL/DDL Data Definition Language SQL.md",
     "SS2026/Datenbanken und Informationssysteme/3. Relationales Datenmodell/Relationales Datenmodell.md",
     "SS2026/Datenbanken und Informationssysteme/3. Relationales Datenmodell/Relationaler Kalkül.md",
-    "SS2026/Datenbanken und Informationssysteme/3. Relationales Datenmodell/Relationale Algebra.md",
-    "SS2026/Datenbanken und Informationssysteme/3. Relationales Datenmodell/ER-Modell zu Relationalem Modell.md"
+    "SS2026/Datenbanken und Informationssysteme/3. Relationales Datenmodell/Relationale Algebra.md"
   ]
 }
\ No newline at end of file
diff --git a/SS2026/Quantum Computing/8. Ket Notation/Anhänge/Pasted image 20260730101012.png b/SS2026/Quantum Computing/8. Ket Notation/Anhänge/Pasted image 20260730101012.png
new file mode 100644
index 0000000..c20017a
Binary files /dev/null and b/SS2026/Quantum Computing/8. Ket Notation/Anhänge/Pasted image 20260730101012.png differ
diff --git a/SS2026/Quantum Computing/8. Ket Notation/Anhänge/Pasted image 20260730101435.png b/SS2026/Quantum Computing/8. Ket Notation/Anhänge/Pasted image 20260730101435.png
new file mode 100644
index 0000000..4725edc
Binary files /dev/null and b/SS2026/Quantum Computing/8. Ket Notation/Anhänge/Pasted image 20260730101435.png differ
diff --git a/SS2026/Quantum Computing/8. Ket Notation/Ket Notation.md b/SS2026/Quantum Computing/8. Ket Notation/Ket Notation.md
new file mode 100644
index 0000000..1f7dd87
--- /dev/null
+++ b/SS2026/Quantum Computing/8. Ket Notation/Ket Notation.md	
@@ -0,0 +1,9 @@
+
+Vectors to describe quantum states can get tedious really quick, so we introduce a new notation.
+We can rewrite a quantum state in the following way:
+![[Pasted image 20260730101012.png]]
+
+To represent the vector $e_i$ as its classical possibility we use $\ket{}$ .
+For a classical possibility x, which is the i-th possibility represented by $e_i$ we use:
+![[Pasted image 20260730101435.png]]
+
diff --git a/SS2026/Quantum Computing/Introduction to Quantum Computing.md b/SS2026/Quantum Computing/Introduction to Quantum Computing.md
index de9057b..915e901 100644
--- a/SS2026/Quantum Computing/Introduction to Quantum Computing.md	
+++ b/SS2026/Quantum Computing/Introduction to Quantum Computing.md	
@@ -5,3 +5,5 @@
 ## 5. [[Partial observing and measuring systems]]
 ## 6. [[Composite Systems]]
 ## 7. [[Quantum Circuits]]
+## 8. [[Ket Notation]]
+