Dynamics of disordered quantum systems with two- and three-dimensional tensor networks

Area of Science:

• Quantum Physics
• Computational Science
• Condensed Matter Physics

Background:

• Recent quantum annealing experiments on D-Wave's Advantage2 system simulated Ising spin glasses.
• These experiments were claimed to surpass classical computational capabilities.

Purpose of the Study:

• To investigate the classical computational feasibility of simulating large-scale quantum annealing dynamics.
• To verify universal Kibble-Zurek physics on systems with hundreds of qubits.

Main Methods:

• Simulated Ising spin-glass models using lattice-specific tensor networks.
• Employed belief propagation (BP) to manage entanglement during time evolution.
• Utilized advanced BP variants for extracting expectation values.

Main Results:

• Achieved state-of-the-art accuracies with modest computational resources.
• Demonstrated scalability of the tensor network approach in both 2D and 3D.
• Verified universal Kibble-Zurek physics on systems involving hundreds of qubits.

Conclusions:

• Classical tensor network simulations, enhanced by belief propagation, can accurately model quantum annealing dynamics.
• The computational reach of classical methods for quantum spin glasses is more extensive than previously claimed.
• This approach provides a scalable pathway for verifying fundamental quantum phenomena.