Update lipkin.do.txt

Author: mhjensen

doc/src/week7/lipkin.do.txt

@@ -1,6 +1,6 @@
-TITLE: Lipkin Model Notebook (DocOnce Conversion)
-AUTHOR:
-DATE:
+TITLE: Lipkin Model Notebook
+AUTHOR: Morten Hjorth-Jensen
+DATE: Spring 2026
 
 
 # VQE for Lipkin Model: Complete Working Implementation
@@ -11,15 +11,6 @@ This notebook implements **Variational Quantum Eigensolver (VQE)** for the Lipki
 - **Computational basis measurements** with proper basis rotations
 - **4-layer hardware-efficient ansatz** (24 parameters)
 
-## Key Corrections Applied:
-1. ✅ **Proper CNOT gates** (correct tensor products)
-2. ✅ **4-layer ansatz** (sufficient expressivity)
-3. ✅ **Correct Y measurement** (H·S†, not S†·H)
-
-## Expected Results:
-- Exact ground state: **E₀ = -3.0**
-- VQE (exact evaluation): **-3.0000** (error < 10⁻¹⁰)
-- VQE (with shots): **~-2.95 to -3.00** (depending on shots and optimization)
 
 
 ## 1. Imports and Setup
@@ -553,30 +544,3 @@ plt.show()
 !ec
 
 
-## 13. Summary
-
-### ✅ All Critical Bugs Fixed:
-
-1. **CNOT Gates:** Proper 3-qubit gates using `kron(CNOT_2qubit, I)`
-2. **Ansatz Depth:** 4 layers (24 parameters) for sufficient expressivity
-3. **Y Measurement:** H·S† rotation (NOT S†·H, NOT H·S)
-
-### 📊 Results:
-
-- **Exact energy:** -3.0000000000
-- **VQE (exact eval):** Essentially exact (error < 10⁻⁹)
-- **VQE (with shots):** Within shot noise of ground state
-
-### 🔬 Physical System:
-
-- **j = 2** (N = 4 particles)
-- **5D quasi-spin space** encoded in 3 qubits
-- **Ground state:** Superposition of |000⟩, |010⟩, |100⟩
-- **Correlation energy:** -1.0 (reference state at -2.0)
-
-### ✓ Verification:
-
-- Hamiltonian is Hermitian ✓
-- Pauli coefficients all real ✓
-- Measurements preserve variational principle ✓
-- VQE converges to ground state ✓