Improving Quantum Computer Simulations

摘要

Operational imperfections and decoherence errors are approximately modelled at gate level as an extension of our massively parallel quantum computer simulator. Decomposing a universal set of basic gates into plane rotations and phase shifts allows to introduce gaussian distributed angle- and phase errors as effective imperfections of steering pulses acting on a qubit in a physical system. Combined with a simple decoherence model we investigate the impact and the interplay of operational and decoherence errors. We analyze the robustness of basic quantum operations and several quantum circuits such as quantum Fourier transformation and Grovers search algorithm. We find out very different sensitivities and describe their dependency on the system size. We provide a graphical tool that allows to investigate the resultant error patterns of our large scale simulations in detail.