Everyone is welcome to attend the online QuSoft seminar with Cristina Cîrstoiu (Cambridge Quantum Computing) with the title Variational fast forwarding for quantum simulation beyond the coherence time.
abstract:
Trotterization-based, iterative approaches to quantum simulation (QS) are restricted to simulation times less than the coherence time of the quantum computer (QC), which limits their utility in the near term. Here, we present a hybrid quantum-classical algorithm, called variational fast forwarding (VFF), for decreasing the quantum circuit depth of QSs. VFF seeks an approximate diagonalization of a short-time simulation to enable longer-time simulations using a constant number of gates. Our error analysis provides two results: (1) the simulation error of VFF scales at worst linearly in the fast-forwarded simulation time, and (2) our cost function’s operational meaning as an upper bound on average-case simulation error provides a natural termination condition for VFF. We implement VFF for the Hubbard, Ising, and Heisenberg models on a simulator. In addition, we implement VFF on Rigetti’s QC to demonstrate simulation beyond the coherence time. Finally, will present recent extensions that improve upon VFF.
Based on joint work with Zoe Holmes, Joseph Iosue, Lukasz Cincio, Patrick J. Coles & Andrew Sornborger from Los Alamos National Lab.
https://www.nature.com/articles/s41534-020-00302-0
Please contact Subhasree Patro or Jop Briet for the link.
