Advantages of Unfair Quantum Ground-State Sampling.

Area of Science:

• Quantum Computing
• Computational Physics
• Optimization

Background:

• The potential advantage of quantum annealers over classical computers is a long-standing debate.
• Recent advancements in quantum annealing hardware have renewed interest in practical applications.
• Demonstrating quantum speedups for optimization problems remains a significant challenge.

Purpose of the Study:

• To investigate quantum annealers' capability to sample ground states of combinatorial optimization problems.
• To compare the sampling behavior of quantum annealers with classical thermal samplers.
• To explore the role of quantum fluctuations in the annealing process.

Main Methods:

• Numerical simulations of stoquastic and non-stoquastic quantum annealing.
• Experimental studies using a prototype quantum annealing processor.
• Analysis of ground-state manifold sampling for spin glass problems.

Main Results:

• Quantum annealers exhibit distinct ground-state sampling patterns compared to thermal optimizers.
• Quantum fluctuations critically influence the final sampling distribution.
• Experimental quantum annealers show unique sampling behavior compared to theoretical models and thermal methods.

Conclusions:

• Quantum annealers can sample ground-state manifolds differently than classical thermal samplers.
• The characteristics of quantum fluctuations are crucial for effective quantum annealing.
• Quantum annealers show promise as complementary tools for advanced sampling algorithms in optimization.