update

Author: mhjensen

README.md

@@ -65,8 +65,8 @@ themes can be covered:
   - Simple Hamiltonian systems and getting started with the first project
 - Teaching material in different formats at https://github.com/CompPhysics/QuantumComputingMachineLearning/tree/gh-pages/doc/pub/week4  
   - _Reading recommendation_: For the discussion of one-qubit, two-qubit and other gates, sections 2.6-2.11 and 3.1-3.4 of Hundt's book Quantum Computing for Programmers, contain most of the relevant information.
-  - Video of lecture to be added  https://youtu.be/
-  - Whiteboard notes at https://github.com/CompPhysics/QuantumComputingMachineLearning/blob/gh-pages/doc/HandWrittenNotes/2026/NotesFebruary12.pdf
+  - Video of lecture at https://youtu.be/4Ew5UNHnsdM
+  - Whiteboard notes at https://github.com/CompPhysics/QuantumComputingMachineLearning/blob/gh-pages/doc/HandWrittenNotes/2026/Lectureweek4.pdf
 
 ##  Note that the topics for the coming weeks may be changed!