Universität Stuttgart
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Item Open Access Rigorous compilation for near-term quantum computers(2024) Brandhofer, Sebastian; Polian, Ilia (Prof.)Quantum computing promises an exponential speedup for computational problems in material sciences, cryptography and drug design that are infeasible to resolve by traditional classical systems. As quantum computing technology matures, larger and more complex quantum states can be prepared on a quantum computer, enabling the resolution of larger problem instances, e.g. breaking larger cryptographic keys or modelling larger molecules accurately for the exploration of novel drugs. Near-term quantum computers, however, are characterized by large error rates, a relatively low number of qubits and a low connectivity between qubits. These characteristics impose strict requirements on the structure of quantum computations that must be incorporated by compilation methods targeting near-term quantum computers in order to ensure compatibility and yield highly accurate results. Rigorous compilation methods have been explored for addressing these requirements as they exactly explore the solution space and thus yield a quantum computation that is optimal with respect to the incorporated requirements. However, previous rigorous compilation methods demonstrate limited applicability and typically focus on one aspect of the imposed requirements, i.e. reducing the duration or the number of swap gates in a quantum computation. In this work, opportunities for improving near-term quantum computations through compilation are explored first. These compilation opportunities are included in rigorous compilation methods to investigate each aspect of the imposed requirements, i.e. the number of qubits, connectivity of qubits, duration and incurred errors. The developed rigorous compilation methods are then evaluated with respect to their ability to enable quantum computations that are otherwise not accessible with near-term quantum technology. Experimental results demonstrate the ability of the developed rigorous compilation methods to extend the computational reach of near-term quantum computers by generating quantum computations with a reduced requirement on the number and connectivity of qubits as well as reducing the duration and incurred errors of performed quantum computations. Furthermore, the developed rigorous compilation methods extend their applicability to quantum circuit partitioning, qubit reuse and the translation between quantum computations generated for distinct quantum technologies. Specifically, a developed rigorous compilation method exploiting the structure of a quantum computation to reuse qubits at runtime yielded a reduction in the required number of qubits of up to 5x and result error by up to 33%. The developed quantum circuit partitioning method optimally distributes a quantum computation to distinct separate partitions, reducing the required number of qubits by 40% and the cost of partitioning by 41% on average. Furthermore, a rigorous compilation method was developed for quantum computers based on neutral atoms that combines swap gate insertions and topology changes to reduce the impact of limited qubit connectivity on the quantum computation duration by up to 58% and on the result fidelity by up to 29%. Finally, the developed quantum circuit adaptation method enables to translate between distinct quantum technologies while considering heterogeneous computational primitives with distinct characteristics to reduce the idle time of qubits by up to 87% and the result fidelity by up to 40%.Item Open Access Fast bidirectional vector wave propagation method showcased on targeted noise reduction in imaging fiber bundles using 3D-printed micro optics(2023) Wende, Marco; Drozella, Johannes; Herkommer, AloisItem Open Access Mass-producible micro-optical elements by injection compression molding and focused ion beam structured titanium molding tools(2020) Ristok, Simon; Roeder, Marcel; Thiele, Simon; Hentschel, Mario; Guenther, Thomas; Zimmermann, André; Herkommer, Alois; Giessen, HaraldItem Open Access Novel X-ray lenses for direct and coherent imaging(2019) Sanli, Umut Tunca; Schütz, Gisela (Prof. Dr.)Item Open Access Depth from axial differential perspective(2022) Faulhaber, Andreas; Krächan, Clara; Haist, TobiasWe introduce an imaging-based passive on-axis technique for measuring the distance of individual objects in complex scenes. Two axially separated pupil positions acquire images (can be realized simultaneously or sequentially). Based on the difference in magnification for objects within the images, the distance to the objects can be inferred. The method avoids some of the disadvantages of passive triangulation sensors (e.g., correspondence, shadowing), is easy to implement and offers high lateral resolution. Due to the principle of operation it is especially suited for applications requiring only low to medium axial resolution. Theoretical findings, as well as follow-up experimental measurements, show obtainable resolutions in the range of few centimeters for distances of up to several meters.Item Open Access Präzise Fahrzeugpositionierung durch Entzerrung der gepulsten magnetischen Flussdichteverteilung einer Ladespule(2017) Martinovic, Dean; Reuss, Hans-Christian (Prof. Dr.-Ing.)Elektrofahrzeuge werden in Zukunft nicht mehr per Kabel, sondern mittels induktiver Ladesysteme mit Strom versorgt. Um eine hohe Ladeleistung sicher übertragen zu können, müssen die Spulen hinreichend genau übereinander positioniert werden, was für den Fahrer eine kaum lösbare Aufgabe darstellt. Das allgemeine Ziel der vorliegenden Arbeit ist es daher, eine neue Methode zu untersuchen, die ein gepulstes Magnetfeld der Ladespule zu dessen Ortung nutzt. Hierbei wird das magnetische Pulssignal durch den ferromagnetischen Unterboden des Elektrofahrzeugs verzerrt. Dieser verändert die Pulsamplitude entsprechend einer unbekannten Abbildung, ohne deren Kenntnis eine präzise und eindeutige Positionierung nicht möglich ist. Die Herausforderung der vorliegenden Arbeit ist daher die Bestimmung dieser Abbildung samt ihrer Eigenschaften und Abhängigkeiten. Theoretische Untersuchungen zeigen, dass die Abbildung allgemein vom nicht-deterministischen magnetischen Zustand des Unterbodenmaterials abhängt und dessen messtechnische Erfassung kaum möglich ist. Im weiteren Verlauf der Untersuchungen wird jedoch hergeleitet, dass die Ladespule, das Elektrofahrzeug und die umgebende Atmosphäre zusammen einen magnetischen Kreis bilden, der aufgrund der sehr hohen Reluktanz der Atmosphäre linear ist. Änderungen des magnetischen Zustands haben folglich keinen Einfluss auf die Abbildung. Diese ist somit reproduzierbar und kann messtechnisch einfach erfasst werden. Die These wird für unterschiedliche magnetische Zustände experimentell nachgewiesen. Basierend auf den Forschungsergebnissen wird ein vollständiger Prototyp entwickelt und in ein Versuchsfahrzeug integriert. Das Gesamtsystem wird anschließend erfolgreich getestet. Die gefundenen Ergebnisse zeigen, dass mittels gepulster magnetischer Felder eine universelle, kostengünstige, sichere und präzise Positionierung von Elektrofahrzeugen möglich ist. Dies unterstreicht das Potential des neuen, komfortablen Positionierungsverfahrens eine Schlüsseltechnologie für die Elektromobilität zu werden.Item Open Access Chiral metamaterials(2016) Eslami, Sahand; Fischer, Peer (Prof. Dr.)Item Open Access Effects of high-power laser radiation on polymers for 3D printing micro-optics(2023) Klein, Sebastian; Ruchka, Pavel; Klumpp, Thomas; Bartels, Nils; Steinle, Tobias; Giessen, HaraldItem Open Access 3D printing of colored micro-optics(2023) Aslani, Valese; Toulouse, Andrea; Schmid, Michael; Giessen, Harald; Haist, Tobias; Herkommer, AloisItem Open Access Entwicklung eines Echtzeit-Triggersystems für Strahl- und Trajektoriensensoren zur Messung von geladenen Mikropartikeln(2018) Strack, Heiko; Srama, Ralf (PD Dr.-Ing.)