Publications (81)
Optimization strategies and artefacts of time-involved small angle neutron scattering experiments
Denis Mettus, Alfonso Chacon, Andreas Bauer +2
Kinetic small-angle neutron scattering provides access to the microscopic properties of mesoscale systems under slow, periodic perturbations. By interlocking the phases of neutron…
Microwave spectroscopy of the low-temperature skyrmion state in Cu2OSeO3
Aisha Aqeel, Jan Sahliger, Takuya Taniguchi +7
In the cubic chiral magnet Cu2OSeO3 a low-temperature skyrmion state (LTS) and a concomitant tilted conical state are observed for magnetic fields parallel to <100>. In this work,…
Subsonic turbulence in smoothed particle hydrodynamics and moving-mesh simulations
Andreas Bauer, Volker Springel
Highly supersonic, compressible turbulence is thought to be of tantamount importance for star formation processes in the interstellar medium. Likewise, cosmic structure formation i…
Reasoning with Data-Centric Business Processes
Andreas Bauer, Peter Baumgartner, Michael Norrish
We describe an approach to modelling and reasoning about data-centric business processes and present a form of general model checking. Our technique extends existing approaches, wh…
Planar fault-tolerant circuits for non-Clifford gates on the 2D color code
Andreas Bauer, Julio C. Magdalena de la Fuente
We introduce a family of scalable planar fault-tolerant circuits that implement logical non-Clifford operations on a 2D color code, such as a logical gate or a logical non-Paul…
Fluctuation-induced first-order phase transition in Dzyaloshinskii-Moriya helimagnets
Marc Janoschek, Markus Garst, Andreas Bauer +4
Two centuries of research on phase transitions have repeatedly highlighted the importance of critical fluctuations that abound in the vicinity of a critical point. They are at the…
Real-space observation of the low-temperature Skyrmion lattice in Cu2OSeO3(100) single crystal
Gerald Malsch, Peter Milde, Dmytro Ivaneiko +4
Cu2OSeO3 is a skyrmion host material in which two distinct thermodynamically stable skyrmion phases were identified. We report magnetic force microscopy imaging of the low-temperat…
Tunable Cooperativity in Coupled Spin--Cavity Systems
Lukas Liensberger, Franz X. Haslbeck, Andreas Bauer +5
We experimentally study the tunability of the cooperativity in coupled spin--cavity systems by changing the magnetic state of the spin system via an external control parameter. As…
Astrophysical hydrodynamics with a high-order discontinuous Galerkin scheme and adaptive mesh refinement
Kevin Schaal, Andreas Bauer, Praveen Chandrashekar +3
Solving the Euler equations of ideal hydrodynamics as accurately and efficiently as possible is a key requirement in many astrophysical simulations. It is therefore important to co…
Resonant elastic X-ray scattering of antiferromagnetic superstructures in EuPtSi
Wolfgang Simeth, Andreas Bauer, Christian Franz +6
We report resonant elastic X-ray scattering (REXS) of long-range magnetic order in EuPtSi, combining different scattering geometries with full linear polarization anal…
Interplay of itinerant magnetism and reentrant spin-glass behavior in FeCr
Georg Benka, Andreas Bauer, Philipp Schmakat +4
When suppressing the itinerant antiferromagnetism in chromium by doping with the isostructual itinerant ferromagnet iron, a dome of spin-glass behavior emerges around a putative qu…
Positron spectroscopy of point defects in the skyrmion-lattice compound MnSi
Markus Reiner, Andreas Bauer, Michael Leitner +7
Outstanding crystalline perfection is a key requirement for the formation of new forms of electronic order in a vast number of widely different materials. Whereas excellent sample…
Field dependence of non-reciprocal magnons in chiral MnSi
Tobias Weber, Johannes Waizner, Gregory Tucker +6
Spin waves in chiral magnetic materials are strongly influenced by the Dzyaloshinskii-Moriya interaction resulting in intriguing phenomena like non-reciprocal magnon propagation an…
Monitorability of -regular languages
Andreas Bauer
Arguably, omega-regular languages play an important role as a specification formalism in many approaches to systems monitoring via runtime verification. However, since their elemen…
Event based classification of Web 2.0 text streams
Andreas Bauer, Christian Wolff
Web 2.0 applications like Twitter or Facebook create a continuous stream of information. This demands new ways of analysis in order to offer insight into this stream right at the m…
High-threshold decoding of non-Pauli codes for 2D universality
Julio C. Magdalena de la Fuente, Noa Feldman, Jens Eisert +1
Topological codes have many desirable properties that allow fault-tolerant quantum computation with relatively low overhead. A core challenge for these codes, however, is to achiev…
Fermi surface and magnetic breakdown in PdGa
Nico Huber, Ivan Volkau, Alexander Engelhardt +4
We study the electronic structure of the chiral semimetal PdGa by means of the de Haas-van Alphen and Shubnikov-de Haas effect. We find that the Fermi surface of PdGa comprises mul…
Low-temperature antiferromagnetic order in orthorhombic CePdAl
Vivek Kumar, Andreas Bauer, Christian Franz +6
We report the magnetization, ac susceptibility, and specific heat of optically float-zoned single crystals of CePdAl. In comparison to the properties of polycrystalline CePdA…
Easy-plane ferromagnetism in single-crystal ErB at low temperatures
Christoph Resch, Georg Benka, Andreas Bauer +1
We report a study of single crystals of the hexagonal rare-earth diboride ErB prepared by means of the self-adjusted flux travelling-solvent floating-zone technique. Measurem…
The Institutional Window: Occupation- and Jurisdiction-Specific Calibration of Liability Signaling for Preserved Human Fallback Capability
Andreas Bauer
Problem definition. When generative AI produces expert artifacts clients cannot distinguish from a competent provider's, the classical cost-based quality signal collapses and only…
Towards a mathematical formalism for classifying phases of matter
Andreas Bauer, Jens Eisert, Carolin Wille
We propose a unified mathematical framework for classifying phases of matter. The framework is based on different types of combinatorial structures with a notion of locality called…
Compositional Studies of Metals with Complex Order by means of the Optical Floating-Zone Technique
Andreas Bauer, Georg Benka, Andreas Neubauer +13
The availability of large high-quality single crystals is an important prerequisite for many studies in solid-state research. The optical floating-zone technique is an elegant meth…
Non-reciprocal magnons in non-centrosymmetric MnSi
Tobias Weber, Johannes Waizner, Gregory S. Tucker +7
Using two cold-neutron triple-axis spectrometers we have succeeded in fully mapping out the field-dependent evolution of the non-reciprocal magnon dispersion relations in all magne…
AutoMoDe - Model-Based Development of Automotive Software
Dirk Ziegenbein, Peter Braun, Ulrich Freund +3
This paper describes first results from the AutoMoDe (Automotive Model-Based Development) project. The overall goal of the project is to develop an integrated methodology for model…
Towards topological fixed-point models beyond gappable boundaries
Andreas Bauer, Jens Eisert, Carolin Wille
We consider fixed-point models for topological phases of matter formulated as discrete path integrals in the language of tensor networks. Such zero-correlation length models with a…
Ferromagnetic resonance with magnetic phase selectivity by means of resonant elastic x-ray scattering on a chiral magnet
Simon Pöllath, Aisha Aqeel, Andreas Bauer +6
Cubic chiral magnets, such as CuOSeO, exhibit a variety of non-collinear spin textures, including a trigonal lattice of spin whirls, so-called skyrmions. Using magnetic…
Decentralised LTL Monitoring
Andreas Bauer, Yliès Falcone
Users wanting to monitor distributed or component-based systems often perceive them as monolithic systems which, seen from the outside, exhibit a uniform behaviour as opposed to ma…
Magnetoelastic effects in the metallic frustrated antiferromagnet CrB
Tadataka Watanabe, Mai Watanabe, Sakurako Suganuma +2
Hexagonal chromium diboride CrB is a metallic frustrated antiferromagnet with a Néel temperature 88 K. In CrB, Cr 3 electrons not only give rise to localized…
Specific heat of the skyrmion lattice phase and field-induced tricritical point in MnSi
Andreas Bauer, Markus Garst, Christian Pfleiderer
We report high-precision measurements of the temperature and magnetic field dependence of the specific heat, C(T,H), across the magnetic phase diagram of MnSi. Clear anomalies esta…
Ultra-high vacuum compatible induction-heated rod casting furnace
Andreas Bauer, Andreas Neubauer, Wolfgang Münzer +5
We report the design of a radio-frequency induction-heated rod casting furnace that permits the preparation of polycrystalline ingots of intermetallic compounds under ultra-high va…
Surface pinning and triggered unwinding of skyrmions in a cubic chiral magnet
Peter Milde, Erik Neuber, Andreas Bauer +2
In the cubic chiral magnet FeCoSi a metastable state comprising of topologically nontrivial spin whirls, so-called skyrmions, may be preserved down to low temperature…
Tensor types and their use in physics
Andreas Bauer, Alexander Nietner
The content of this paper can be roughly organized into a three-level hierarchy of generality. At the first, most general level, we introduce a new language which allows us to expr…
Toward Scalable Access to Neurodevelopmental Screening: Insights, Implementation, and Challenges
Andreas Bauer, William Bosl, Oliver Aalami +1
Children with neurodevelopmental disorders require timely intervention to improve long-term outcomes, yet early screening remains inaccessible in many regions. A scalable solution…
Field-induced reorientation of helimagnetic order in CuOSeO probed by magnetic force microscopy
Peter Milde, Laura Köhler, Erik Neuber +6
CuOSeO is an insulating skyrmion-host material with a magnetoelectric coupling giving rise to an electric polarization with a characteristic dependence on the magnetic fiel…
CiRA: An Open-Source Python Package for Automated Generation of Test Case Descriptions from Natural Language Requirements
Julian Frattini, Jannik Fischbach, Andreas Bauer
Deriving acceptance tests from high-level, natural language requirements that achieve full coverage is a major manual challenge at the interface between requirements engineering an…
Symmetry-enforced topological nodal planes at the Fermi surface of a chiral magnet
Marc A. Wilde, Matthias Dodenhöft, Arthur Niedermayr +5
Following over a decade of intense efforts to enable major progress in spintronics devices and quantum information technology by means of materials in which the electronic structur…
A decidable policy language for history-based transaction monitoring
Andreas Bauer, Rajeev Gore, Alwen Tiu
Online trading invariably involves dealings between strangers, so it is important for one party to be able to judge objectively the trustworthiness of the other. In such a setting,…
Scanning probe microscopy in an ultra-low vibration closed-cycle cryostat
Francesca Paola Quacquarelli, Jorge Puebla, Thomas Scheler +8
We report on state-of-the-art scanning probe microscopy measurements performed in a pulse tube based top-loading closed-cycle cryostat with a base temperature of 4 K and a 9 T magn…
Quantum mechanics is *-algebras and tensor networks
Andreas Bauer
We provide a systematic approach to quantum mechanics from an information-theoretic perspective using the language of tensor networks. Our formulation needs only a single kind of o…
Non-reciprocal spin excitations across the skyrmion-paramagnetic phase transition in MnSi
Tobias Weber, Karin Schmalzl, Johannes Waizner +3
The magnetic excitations of the skyrmion lattice in MnSi comprise a multitude of individual modes, which are non-reciprocal and thereby propagate unidirectionally. We report inelas…
History dependence of the magnetic properties of single-crystal FeCoSi
Andreas Bauer, Markus Garst, Christian Pfleiderer
We report the magnetization, ac susceptibility, and specific heat of optically float-zoned single crystals of FeCoSi, . We determine the magnet…
The Last Costly Signal: How Generative AI Collapses Competence Signaling and Why Liability Sustains Markets for Expert Services
Andreas Bauer
The paper models how generative AI makes expertise reports cheap, breaking traditional costly‑signal mechanisms in expert‑service markets, and shows that liability‑based warranties…
No Free Lunch: Research Software Testing in Teaching
Michael Dorner, Andreas Bauer, Florian Angermeir
Software is at the core of most scientific discoveries today. Therefore, the quality of research results highly depends on the quality of the research software. Rigorous testing, a…
Simulating Turbulence Using the Astrophysical Discontinuous Galerkin Code TENET
Andreas Bauer, Kevin Schaal, Volker Springel +3
In astrophysics, the two main methods traditionally in use for solving the Euler equations of ideal fluid dynamics are smoothed particle hydrodynamics and finite volume discretizat…
Improving the convergence properties of the moving-mesh code AREPO
Ruediger Pakmor, Volker Springel, Andreas Bauer +5
Accurate numerical solutions of the equations of hydrodynamics play an ever more important role in many fields of astrophysics. In this work, we reinvestigate the accuracy of the m…
Generic aspects of skyrmion lattices in chiral magnets
Andreas Bauer, Christian Pfleiderer
Magnetic skyrmions are topologically non-trivial spin whirls that may not be transformed continuously into topologically trivial states such as ferromagnetic spin alignment. In rec…
Network of topological nodal planes, multifold degeneracies, and Weyl points in CoSi
Nico Huber, Kirill Alpin, Grace L. Causer +7
We report the identification of symmetry-enforced nodal planes (NPs) in CoSi providing the missing topological charges in an entire network of band-crossings comprising in addition…
The x+y Floquet code: A simple example for topological quantum computation in the path integral approach
Andreas Bauer
The path-integral approach to topological quantum error correction provides a unified way to construct and analyze fault-tolerant circuits in spacetime. In this work, we demonstrat…
Bulk-to-boundary anyon fusion from microscopic models
Julio C. Magdalena de la Fuente, Jens Eisert, Andreas Bauer
Topological quantum error correction based on the manipulation of the anyonic defects constitutes one of the most promising frameworks towards realizing fault-tolerant quantum devi…
Optical creation and annihilation of skyrmion patches in a bulk chiral magnet
Jantje Kalin, Sibylle Sievers, Daniel Kalin +6
A key challenge for the realization of future skyrmion devices comprises the controlled creation, annihilation and detection of these topologically non-trivial magnetic spin textur…
Optically excited spin dynamics of thermally metastable skyrmions in FeCoSi
Jantje Kalin, Sibylle Sievers, Heiko Füser +5
We investigate the microwave spin excitations of the cubic chiral magnet FeCoSi as driven by the thermal modulation of magnetic interactions via laser heating and…
Polarized inelastic neutron scattering of non-reciprocal spin waves in MnSi
Tobias Weber, Johannes Waizner, Paul Steffens +4
We report spin-polarized inelastic neutron scattering of the dynamical structure factor of the conical magnetic helix in the cubic chiral magnet MnSi. We find that the spectral wei…
Low-overhead non-Clifford fault-tolerant circuits for all non-chiral abelian topological phases
Andreas Bauer
We propose a family of explicit geometrically local circuits on a 2-dimensional planar grid of qudits, realizing any abelian non-chiral topological phase as an actively error-corre…
Volatility in the Relative Standard Deviation of Target Fulfilment as Key Performance Indicator (KPI)
Andreas Bauer, Jasna Omeragic
In this study, we identify the relative standard deviation volatility (RSD volatility) in the individual target time fulfilment of the complete set of comparables (e.g., all indivi…
Efficient classical algorithms for simulating symmetric quantum systems
Eric R. Anschuetz, Andreas Bauer, Bobak T. Kiani +1
In light of recently proposed quantum algorithms that incorporate symmetries in the hope of quantum advantage, we show that with symmetries that are restrictive enough, classical a…
Quo Vadis, Code Review? Exploring the Future of Code Review
Michael Dorner, Andreas Bauer, Darja Å mite +6
Context: Code review has long been a core practice in collaborative software engineering. As automation becomes increasingly embedded in development workflows, the role and functio…
MIEZE Neutron Spin-Echo Spectroscopy of Strongly Correlated Electron Systems
Christian Franz, Steffen Säubert, Andreas Wendl +8
Recent progress in neutron spin-echo spectroscopy by means of longitudinal Modulation of IntEnsity with Zero Effort (MIEZE) is reviewed. Key technical characteristics are summarize…
Fermi surface of the chiral topological semimetal CoSi
Nico Huber, Sanu Mishra, Ilya Sheikin +6
We report a study of the Fermi surface of the chiral semimetal CoSi and its relationship to a network of multifold topological crossing points,Weyl points, and topological nodal pl…
Confined dipole and exchange spin waves in a bulk chiral magnet with Dzyaloshinskii-Moriya interaction
Ping Che, Ioannis Stasinopoulos, Andrea Mucchietto +5
The Dzyaloshinskii-Moriya interaction (DMI) has an impact on excited spin waves in the chiral magnet CuOSeO by means of introducing asymmetry on their dispersion relations.…
Hydrogen Reionization in the Illustris universe
Andreas Bauer, Volker Springel, Mark Vogelsberger +5
Hydrodynamical simulations of galaxy formation such as the Illustris simulations have progressed to a state where they approximately reproduce the observed stellar mass function fr…
Disentangling modular Walker-Wang models via fermionic invertible boundaries
Andreas Bauer
Walker-Wang models are fixed-point models of topological order in dimensions constructed from a braided fusion category. For a modular input category , the model…
Comparative Analysis of Radiomic Features and Gene Expression Profiles in Histopathology Data Using Graph Neural Networks
Luis Carlos Rivera Monroy, Leonhard Rist, Martin Eberhardt +5
This study leverages graph neural networks to integrate MELC data with Radiomic-extracted features for melanoma classification, focusing on cell-wise analysis. It assesses the effe…
Cyclotron mass-selective de Haas-van Alphen measurements using temperature modulation
Michelle Hollricher, Andreas Bauer, Leo Maximov +3
We present a temperature-modulated de Haas-van Alphen measurement technique that allows selective addressing of quantum oscillations with different effective masses usin…
Generalized topological state-sum constructions and their universality
Andreas Bauer
We formalize and generalize the concept of a topological state-sum construction using the language of tensor networks. We give examples for constructions that are possibly more gen…
Topological error correcting processes from fixed-point path integrals
Andreas Bauer
We propose a unifying paradigm for analyzing and constructing topological quantum error correcting codes as dynamical circuits of geometrically local channels and measurements. To…
Quadratic tensors as a unification of Clifford, Gaussian, and free-fermion physics
Andreas Bauer, Seth Lloyd
Certain families of quantum mechanical models can be described and solved efficiently on a classical computer, including qubit or qudit Clifford circuits and stabilizer codes, free…
Reflections on the Reproducibility of Commercial LLM Performance in Empirical Software Engineering Studies
Florian Angermeir, Maximilian Amougou, Mark Kreitz +6
Large Language Models have gained remarkable interest in industry and academia. The increasing interest in LLMs in academia is also reflected in the number of publications on this…
Parametric Sequential Method for MRI-based Wall Shear Stress Quantification
Nina Shokina, Gabriel Teschner, Andreas Bauer +4
Wall shear stress (WSS) has been suggested as a potential biomarker in various cardiovascular diseases and it can be estimated from phase-contrast Magnetic Resonance Imaging (PC-MR…
Shaking and pushing skyrmions: Formation of a non-equilibrium phase with zero critical current
Felix Rucker, Alla Bezvershenko, Denis Mettus +4
In three-dimensional chiral magnets, skyrmions are line-like objects oriented parallel to the applied magnetic field. The efficient coupling of magnetic skyrmion lattices to spin c…
Quantum Oscillations of the Quasiparticle Lifetime in a Metal
Nico Huber, Valentin Leeb, Andreas Bauer +4
Following nearly a century of research, it remains a puzzle that the low-lying excitations of metals are remarkably well explained by effective single-particle theories of non-inte…
Graphical Calculus for Fermionic Tensors
Yuanjie Ren, Kaifeng Bu, Andreas Bauer
We introduce a graphical calculus, consisting of a set of fermionic tensors with tensor-network equations, which can be used to perform various computations in fermionic many-body…
Spin-resolved Fermi surface of the localized ferromagnetic Heusler compound CuMnAl measured with spin-polarized positron annihilation
Josef A. Weber, Andreas Bauer, Peter Böni +7
We determined the bulk electronic structure in the prototypical Heusler compound CuMnAl by measuring the Angular Correlation of Annihilation Radiation (2D-ACAR) using spin-pola…
Low-temperature properties of single-crystal CrB
Andreas Bauer, Alexander Regnat, Christian G. F. Blum +6
We report the low-temperature properties of B-enriched single-crystal CrB as prepared from high-purity Cr and B powder by a solid-state reaction and optical float zoni…
Evolution of the spin dynamics during freezing in the spin-glass FeCr
Steffen Säubert, Christian Franz, Johanna K. Jochum +5
In the iron--chromium system, FeCr, a wide dome of spin-glass behavior emerges when the ferromagnetism of iron is suppressed and the antiferromagnetism of chromium em…
Finding diagonal logical gates in CSS codes and circuits
Andreas Bauer
The paper introduces efficient algorithms to identify all diagonal logical gates that preserve the code space of CSS codes or circuits, enabling the systematic discovery of fault‑t…
From propositional to first-order monitoring
Andreas Bauer, Jan-Christoph Küster, Gil Vegliach
The main purpose of this paper is to introduce a first-order temporal logic, LTLFO, and a corresponding monitor construction based on a new type of automaton, called spawning autom…
The Fallback as Signal: Preserved Human Skill, Liability, and Competence Signaling in Credence-Good Markets under Improving AI
Andreas Bauer
Firms that deploy improving but imperfect AI must decide how much to keep human workers engaged. Engagement lowers current output yet builds the fallback skill the firm needs when…
Platform-Centric Android Monitoring---Modular and Efficient
Jan-Christoph Kuester, Andreas Bauer
We present an add-on for the Android platform, capable of intercepting nearly all interactions between apps or apps with the platform, including arguments of method invocations in…
Development of a Modular Optically Detected Magnetic Resonance Setup for Optical Experiments in a Variable Temperature Insert
Anh Tong, Andreas Bauer, Markus Kleinhans +6
We developed an optically detected magnetic resonance (ODMR) setup designed for compatibility with a widely used, commercially available helium bath cryostat equipped with a variab…
Universal fault tolerant quantum computation in 2D without getting tied in knots
Margarita Davydova, Andreas Bauer, Julio C. Magdalena de la Fuente +3
We show how to perform scalable fault-tolerant non-Clifford gates in two dimensions by introducing domain walls between the surface code and a non-Abelian topological code whose co…
Magnetohydrodynamics on an unstructured moving grid
Ruediger Pakmor, Andreas Bauer, Volker Springel
Magnetic fields play an important role in astrophysics on a wide variety of scales, ranging from the Sun and compact objects to galaxies and galaxy clusters. Here we discuss a nove…