Previous talks at the SCCS Colloquium

Andrea de Girolamo: Hybrid tensor network contraction methods for random quantum circuits

SCCS Colloquium |


Tensor networks are incredibly powerful tools to simulate quantum circuits, and have therefore been used for the experimental verification of quantum supremacy on incredibly complicated problems. A hybrid Schrödinger-Feynman contraction approach has proved to be extremely efficient when it comes to the simulation of the Sycamore circuit. However, precise and optimal heuristics to choose between multiple possible solutions are still undefined. In this work, we first go through Schrödinger, Feynman and hybrid contraction methods and estimate their complexity in terms of both time and memory consumption. We then describe our program, which is able, thanks to these estimations, to predict the cost of the contraction algorithms without performing huge computations. We describe the structures where we tested the methods, namely the Sycamore quantum circuit and a generic random quantum circuit, and we define our simple heuristics and possible alternatives to them. Finally, we show how the behavior of the hybrid complexity follows the expectations when modifying the simulation parameter, and check which parameter gives the best result with our heuristics.

Guided research presentation. Andrea is advised by Keefe Huang.