Previous talks at the SCCS Colloquium

Ayse Kotil: Classical Optimization of Quantum Simulation Circuits

SCCS Colloquium |


In this work, we tackle the problem of simulating the time evolution of quantum systems, in particular, those that are governed by the Hamiltonian of a one-dimensional nearest-neighbor Heisenberg model with periodic boundary conditions. We choose a Strang-splitting method to simulate the quantum system and investigate whether we can improve on the approximation achieved by the splitting with classical optimization procedures. Our error function is the norm of the difference between the exact time evolution operator and the initial splitting. We classically optimize the 2-qubit gates resulting from the splitting layer by layer with a modified Gradient Descent algorithm. We repeat the process until we converge to a quantum circuit that is closer to the exact time evolution operator. This way, we show that a better approximation may be achieved using less time steps and thus fewer gates.

Guided research presentation. Ayse is advised by Prof. Christian Mendl.