Track
Variational Algorithms
VQE, QAOA, and the hybrid classical/quantum paradigm that works on today's hardware.
- Level
- Intermediate
- Tutorials
- 2
- Reading time
- ~49 min
Curriculum
- 01
Variational Quantum Eigensolver (VQE) From Scratch
VQE finds ground-state energies of quantum Hamiltonians using a hybrid classical-quantum loop. This tutorial derives the variational principle, explains Jordan-Wigner fermion encoding, builds an H₂ ground-state computation end-to-end in Qiskit, and honestly discusses barren plateaus and why the ansatz choice makes or breaks the algorithm.
intermediate · ~26 min · prereq: Algorithms track (Tutorials 8-12)
- 02
QAOA for Combinatorial Optimization
QAOA encodes a combinatorial problem as a cost Hamiltonian, prepares a variational state by alternating cost and mixer evolutions, and uses a classical optimizer to find approximate solutions. This tutorial derives the MaxCut case from scratch, runs it in Qiskit, and honestly compares QAOA to classical baselines like Goemans-Williamson.
intermediate · ~23 min · prereq: Tutorial 13: Variational Quantum Eigensolver