Adaptive variational quantum computing algorithm for nonequilibrium dynamics simulations

Alert
Current COVID-19 Community Level: LOW (Updated June 28) CDC COVID-19 County Check
Scientific Achievement

A new adaptive quantum computing algorithm demonstrates high-fidelity quantum simulations, with linear system

schematic illustration of algorithm
Schematic illustration of algorithm
 

size scaling.

Significance and Impact

This scalable algorithm creates opportunities to study quantum dynamics of significantly larger systems on current and near-term quantum devices.

Research Details
Algorithm self-adaptively constructs ansatz based on McLachlan’s variational principle.
Resulting circuits are two orders of magnitude shorter than for standard first-order Trotter expansion.
Calculations for different integrable and non-integrable spin models and quench protocols.
Circuit grows linearly with time at initial simulation stage, followed by slowing down at saturation.
circuit saturation
Circuit saturation and scalability of practical calculations of N-site models for fixed times.

 

Linear system size scaling for fixed simulation times. 
 

Y.-X. Yao, N. Gomes, F. Zhang, C.-Z. Wang, K.-M. Ho, T. Iadecola, and P. P. Orth, Adaptive Variational Quantum Dynamics Simulation, PRX Quantum 2, 030307 (2021).