Quantum Alternating Operator Ansatz (QAOA) beyond low depth with gradually changing unitaries

Understand

The Quantum Approximate Optimization Algorithm and its generalization to Quantum Alternating Operator Ansatz (QAOA) is a promising approach for applying quantum computers to challenging problems such as combinatorial optimization and computational chemistry.

• In this paper, we study the underlying mechanisms governing the behavior of QAOA circuits beyond shallow depth in the practically relevant setting of gradually varying unitaries.
• We use the discrete adiabatic theorem, which complements and generalizes the insights obtained from the continuous-time adiabatic theorem primarily considered in prior work.
• Our analysis explains some general properties that are conspicuously depicted in the recently introduced QAOA performance diagrams.