Fraunhofer-GesellschaftThe Fraunhofer IAO develops quantum algorithms based on qubitization and quantum signal processing (QSP) for the efficient simulation of quantum mechanical systems. Quantum computers address the exponential increase in the dimension of the Hilbert space, thereby enabling a drastic reduction in computational complexity. Despite the high resource requirements resulting from complex gate sequences in qubitization operators, the gate complexity can be significantly reduced using variational methods. These methods utilize parameterized quantum circuits that take into account properties such as the symmetries of the simulated system. In addition to quantum simulations, such algorithms also enable the solution of linear systems of equations and can be used as subroutines in larger algorithms.
Simulation of photonic systems using quantum algorithms, particularly regarding the propagation of light in structured media for the rapid optimization of nanophotonic components. Here, we leverage the ability of quantum computers to physically model interference in order to solve multipath interference systems with exponential speedup. This is particularly relevant for nanophotonics, where classically complex wavefields must be calculated, even though ultimately only a few figures of merit—such as diffraction efficiency—are optimized.
At Fraunhofer IGD, ZAQC researches new approaches to simulating molecules and quantum-chemical systems. This includes hybrid simulation methods and quantum-inspired tensor-network approaches, which are investigated particularly for applications in chemistry and pharmaceuticals.