Recent Submissions
HyperLoop : hyperspectral assisted loop closure detection in 3DGS SLAM system for planetary exploration
(2025) Bhalla, Annie
Autonomous navigation of planetary rovers remains a major challenge in space exploration, especially in environments that are featureless, poorly illuminated, or obscured by dust. Recent progress in Simultaneous Localization and Mapping (SLAM) based on 3D Gaussian Splatting (3DGS) [1] has demonstrated the ability to generate dense and accurate 3D maps while preserving global consistency through loop closure. Such systems perform reliably in structured settings, where conventional loop closure detection methods - whether relying on handcrafted visual place recognition techniques such as Bag-of-Visual-Words with SIFT descriptors, or deep learning models trained on object-centric datasets - are effective at producing robust descriptors. However, in adverse planetary conditions these methods face significant limitations, often leading to degraded loop closure detection and increased localization drift.
To address these challenges, this research investigates the integration of hyperspectral imaging (HSD), particularly in the near-infrared range, into the loop closure module of 3DGS-based SLAM system-LoopSplat. Hyperspectral descriptors are extracted to capture material-level properties of the environment, thereby providing additional semantic information that complements RGB features and strengthens loop closure detection. Multiple descriptor extraction techniques for both RGB and HSI modalities are explored to evaluate their effectiveness in unstructured planetary-like environments.
The proposed framework is assessed on datasets collected at the Moon-Mars Outdoor Test Site (MMOTS) of the German Aerospace Center (DLR). Results demonstrate the feasibility of incorporating HSI into SLAM pipelines, showing improved loop closure reliability and localization accuracy in challenging conditions. Performance remains highly dependent on sensor’s spectral range and the ability to capture discriminative material cues.
Overall, this work highlights the potential of hyperspectral imaging to enhance SLAM for planetary exploration, offering a step toward more robust and reliable rover autonomy in unstructured extraterrestrial terrains.
Lebenszyklusanalyse des Wärmeträgermediums und der Rohrleitungen eines kalten Nahwärmenetzes
(2026) Huber, Peer; Fischer, Julian; Drück, Harald; Hafner, Bernd; Dott, Ralf
Inverse Verfahren zur flächenaufgelösten Wärmestromdichtemessung
(2026) Dürnhofer, Christian; Fasoulas, Stefanos (Prof. Dr.-Ing.)
The bitter truth about gate-based quantum algorithms in the NISQ era
(2020) Leymann, Frank; Barzen, Johanna
Implementing a gate-based quantum algorithm on an noisy intermediate scale quantum (NISQ) device has several challenges that arise from the fact that such devices are noisy and have limited quantum resources. Thus, various factors contributing to the depth and width as well as to the noise of an implementation of a gate-based algorithm must be understood in order to assess whether an implementation will execute successfully on a given NISQ device. In this contribution, we discuss these factors and their impact on algorithm implementations. Especially, we will cover state preparation, oracle expansion, connectivity, circuit rewriting, and readout: these factors are very often ignored when presenting a gate-based algorithm but they are crucial when implementing such an algorithm on near-term quantum computers. Our contribution will help developers in charge of realizing gate-based algorithms on such machines in (i) achieving an executable implementation, and (ii) assessing the success of their implementation on a given machine.
Microscopic 3D printed optical tweezers for atomic quantum technology
(2022) Ruchka, Pavel; Hammer, Sina; Rockenhäuser, Marian; Albrecht, Ralf; Drozella, Johannes; Thiele, Simon; Giessen, Harald; Langen, Tim
Trapping of single ultracold atoms is an important tool for applications ranging from quantum computation and communication to sensing. However, most experimental setups, while very precise and versatile, can only be operated in specialized laboratory environments due to their large size, complexity and high cost. Here, we introduce a new trapping concept for ultracold atoms in optical tweezers based on micrometer-scale lenses that are 3D printed onto the tip of standard optical fibers. The unique properties of these lenses make them suitable for both trapping individual atoms and capturing their fluorescence with high efficiency. In an exploratory experiment, we have established the vacuum compatibility and robustness of the structures, and successfully formed a magneto-optical trap for ultracold atoms in their immediate vicinity. This makes them promising components for portable atomic quantum devices.
Quantum witness of a damped qubit with generalized measurements
(2019) Bojer, Manuel; Friedenberger, Alexander; Lutz, Eric
We evaluate the quantum witness based on the no-signaling-in-time condition of a damped two-level system for nonselective generalized measurements of varying strength. We explicitly compute its dependence on the measurement strength for a generic example. We find a vanishing derivative for weak measurements and an infinite derivative in the limit of projective measurements. The quantum witness is hence mostly insensitive to the strength of the measurement in the weak measurement regime and displays a singular, extremely sensitive dependence for strong measurements. We finally relate this behavior to that of the measurement disturbance defined in terms of the fidelity between pre-measurement and post-measurement states.
Probing DNA nucleobases with diamond (111) surfaces
(2019) Putra, Miftahussurur Hamidi; Fyta, Maria
DNA units, the nucleobases, are probed with diamond (111) surfaces. The nucleobases are placed on top of a diamond surface interacting in a very specific way with the surface atoms. Different elements, such as hydrogen, nitrogen, and fluorine are chosen for the termination of the diamond. The energetic features and electronic properties of the combined system ’nucleobase/diamond surface’ are thoroughly studied using quantum-mechanical calculations. These point to nucleobase- and termination-specific characteristics linking to the potential of using diamond surfaces for identifying the DNA nucleobases. Focus is further given on mixed surfaces with a varying nitrogen and hydrogen coverage. For these, we provide pathways for tuning the electronic band gap of the surface/nucleobase complex with the nitrogen content of the surface. The results could unravel a clear crossover in the surface electron affinity and its relation to a reversal in the positions of the electronic band extremes from the material to the molecule and vice versa. These features link to a further selective modulation of the electronic transport and the excitation properties of the complexes with a strong biosensing potential.
Bridging the trust gap in conversational AI : a new trust model for chatbots
(2026) Berberena, Tabea; Wirzberger, Maria (Prof. Dr. rer. nat.)
Conversational AI systems such as chatbots are increasingly embedded in everyday life, shaping access to services, information, and social interactions. Trust plays a pivotal role in whether users accept, rely on, or reject these systems. Yet, existing models of trust in AI remain predominantly cognitive and performance-focused, insufficiently addressing the emotional and social dynamics that underpin trust formation. This dissertation investigates two underexplored psychological dimensions of human-chatbot trust, that is users’ momentary emotional states and implicit social biases, particularly gender and age-related stereotypes. Through two controlled experimental studies, the contributions examine (1) how momentary emotional states influence trust after faulty chatbot behavior and (2) how biases influence initial trust judgments and trusting behavior toward chatbots differing in gender and age. Across both studies, results demonstrate that trust is shaped by both, affective states and social heuristics. Building on these empirical insights, the dissertation develops a novel, systems-theoretic conceptual model of trust in chatbots. The model conceptualizes trust as a dynamic process emerging in feedback loops between performance, emotional state, relational distance, anthropomorphism, and user bias. A simulation-based implementation of this model illustrates how trust can evolve along different trajectories, stabilizing, recovering, or breaking down depending on the interplay of emotional and cognitive conditions. The dissertation makes three key contributions. First, it offers a theoretical advancement by extending trust in technology frameworks to include affective and socio-cognitive dimensions, providing a more comprehensive understanding of trust in AI-mediated interaction. Second, it contributes methodologically by combining controlled experimentation with system-dynamics simulation to capture and test feedback-driven trust processes over time. Third, it offers practical implications for the ethical design of conversational AI, highlighting the need for systems that are sensitive to users’ emotional contexts and resilient to the effects of social bias. Overall, the findings underscore that developing trustworthy conversational AI cannot be reduced to improving technical accuracy or functionality only. It requires an integrative perspective that recognizes trust as a deeply human phenomenon, shaped by emotions, social expectations, and cultural biases. Only by addressing these dimensions can conversational AI systems be designed in ways that promote fair, inclusive, and sustainable adoption.
Roadmap on soft robotics : multifunctionality, adaptability and growth without borders
(2022) Mazzolai, Barbara; Mondini, Alessio; Del Dottore, Emanuela; Margheri, Laura; Carpi, Federico; Suzumori, Koichi; Cianchetti, Matteo; Speck, Thomas; Smoukov, Stoyan K.; Burgert, Ingo; Keplinger, Tobias; Siqueira, Gilberto De Freitas; Vanneste, Felix; Goury, Olivier; Duriez, Christian; Nanayakkara, Thrishantha; Vanderborght, Bram; Brancart, Joost; Terryn, Seppe; Rich, Steven I.; Liu, Ruiyuan; Fukuda, Kenjiro; Someya, Takao; Calisti, Marcello; Laschi, Cecilia; Sun, Wenguang; Wang, Gang; Wen, Li; Baines, Robert; Patiballa, Sree Kalyan; Kramer-Bottiglio, Rebecca; Rus, Daniela; Fischer, Peer; Simmel, Friedrich C.; Lendlein, Andreas
Soft robotics aims at creating systems with improved performance of movement and adaptability in unknown, challenging, environments and with higher level of safety during interactions with humans. This Roadmap on Soft Robotics covers selected aspects for the design of soft robots significantly linked to the area of multifunctional materials, as these are considered a fundamental component in the design of soft robots for an improvement of their peculiar abilities, such as morphing, adaptivity and growth. The roadmap includes different approaches for components and systems design, bioinspired materials, methodologies for building soft robots, strategies for the implementation and control of their functionalities and behavior, and examples of soft-bodied systems showing abilities across different environments. For each covered topic, the author(s) describe the current status and research directions, current and future challenges, and perspective advances in science and technology to meet the challenges.
Nanostructured graphene for nanoscale electron paramagnetic resonance spectroscopy
(2020) Marie, Luke St.; El Fatimy, Abdel; Hrubý, Jakub; Nemec, Ivan; Hunt, James; Myers-Ward, Rachael; Gaskill, D. Kurt; Kruskopf, Mattias; Yang, Yanfei; Elmquist, Randolph; Marx, Raphael; van Slageren, Joris; Neugebauer, Petr; Barbara, Paola
The opening of a quantum confinement gap in nanostructured graphene yields extremely sensitive photodetectors, with electrical noise equivalent power lower than 10-15 W Hz-0.5 at temperatures below 3 K, for detection of radiation in a very broad frequency range, including ultraviolet, visible and terahertz. Here we demonstrate the operation of these detectors in the presence of magnetic field as high as 7 T, paving the way to in situ spectroscopy of molecular nanomagnets.