Day 787: Ground State and Code Space

Learning Objectives

• •**State** the ground state condition: $A_v|\psi\rangle = B_p|\psi\rangle = +1|\psi\rangle$
• •**Prove** the ground state degeneracy equals 4 on the torus
• •**Construct** explicit ground state wavefunctions
• •**Explain** the connection between degeneracy and logical qubits
• •**Write** the toric code Hamiltonian and analyze its spectrum
• •**Calculate** the energy gap protecting the code space

Today's Schedule (7 hours)