arXiv subjects

Lukas Möller

Publications and source records attributed to Lukas Möller.

6 recordsLinked to original sources

arXiv2026

Isotope shifts and hyperfine splitting of the ${}^{1}S_{0}\rightarrow{}^{3}P_{1}$ transition in zinc

We report laser-induced-fluorescence spectroscopy of the ${}^1S_0 \rightarrow {}^3P_1$ intercombination transition in neutral zinc at $307.6~\mathrm{nm}$. Isotope shifts are measured for all stable isotopes with kHz-level precision, improving previous data by about two orders of magnitude. For $^{67}\mathrm{Zn}$, we resolve the excited-state hyperfine structure and determine $δν^{67,64}_{\rm COG}=1085.933(7)~\mathrm{MHz}$, $A=608.922(3)~\mathrm{MHz}$, and $B=-18.995(10)~\mathrm{MHz}$. A King plot comparison with the ${}^1S_0 \rightarrow {}^1P_1$ 214-nm transition results in field- and mass-shift parameters of $F_{307.6,214}=1.17(5)$ and $K_{307.6,214}=-153(60)~\mathrm{GHz\ u}$. These results provide the spectroscopic basis for narrow-line cooling and precision measurements based on zinc, including the development of an optical clock.

physics.atom-ph↗

arXiv2025

Magneto-optical trapping of Zinc

We report on laser cooling and magneto-optical trapping of atomic zinc. The atoms are cooled using the 213.9\,nm $^1$S$_0$ $\rightarrow$ $^1$P$_1$ transition, making this the shortest wavelength employed for magneto-optical trapping thus far. We demonstrate trapping of all stable isotopes of zinc, including the fermionic isotope $^{67}$Zn, which features a very narrow $^1$S$_0$ $\rightarrow$ $^3$P$_0$ transition that could form the basis of an optical atomic clock. We characterize the influence of various parameters on the MOT population and loading rate. The results presented here constitute the first step towards the application of zinc for high-precision optical spectroscopy and quantum information processing.

physics.atom-ph↗

arXiv2025

Cppless: Single-Source and High-Performance Serverless Programming in C++

The rise of serverless computing introduced a new class of scalable, elastic and widely available parallel workers in the cloud. Many systems and applications benefit from offloading computations and parallel tasks to dynamically allocated resources. However, the developers of C++ applications find it difficult to integrate functions due to complex deployment, lack of compatibility between client and cloud environments, and loosely typed input and output data. To enable single-source and efficient serverless acceleration in C++, we introduce Cppless, an end-to-end framework for implementing remote functions which handles the creation, deployment, and invocation of serverless functions. Cppless is built on top of LLVM and requires only two compiler extensions to automatically extract C++ function objects and deploy them to the cloud. We demonstrate that offloading parallel computations, such as from a C++ application to serverless workers, can provide up to 59x speedup with minimal cost increase while requiring only minor code modifications.

cs.DC↗

arXiv2025

A tunable, continuous-wave 130-mW laser at 213 nm

We present a tunable, continuous-wave (CW) laser system emitting at 213 nm, based on the frequency quadrupling of a single Ti:sapph laser. The setup features two sequential, cavity-enhanced second-harmonic generation (SHG) stages. The first stage uses an LBO crystal and achieves a conversion efficiency of over 80%, yielding up to 3.3 W at 426 nm. The second stage employs a Brewster-cut BBO crystal with an elliptical beam waist to mitigate UV-induced degradation, producing up to 130 mW of deep UV light. The system demonstrates stable operation over several hours and is well suited for applications in atomic physics, spectroscopy, and materials science.

physics.optics↗

arXiv2024

Isotope shift measurement of the 423-nm transition in neutral Ca

We report on saturated absorption spectroscopy measurements of the $(4s^2) ^{1}S_0\rightarrow(4s4p) ^{1}P_1$ transition for the four most abundant even-mass isotopes in calcium. By referencing the laser locked to an ultralow expansion cavity and carefully investigating systematic errors, isotope shifts are determined with a precision below 100 kHz, improving previously reported values by a factor of about five. A King plot analysis employing literature values of the 729-nm transition in Ca ions shows excellent linearity. The field and mass shift parameters are determined from King plots with other transitions.

physics.atom-ph↗

arXiv2016

Evaluating direct transcription and nonlinear optimization methods for robot motion planning

This paper studies existing direct transcription methods for trajectory optimization applied to robot motion planning. There are diverse alternatives for the implementation of direct transcription. In this study we analyze the effects of such alternatives when solving a robotics problem. Different parameters such as integration scheme, number of discretization nodes, initialization strategies and complexity of the problem are evaluated. We measure the performance of the methods in terms of computational time, accuracy and quality of the solution. Additionally, we compare two optimization methodologies frequently used to solve the transcribed problem, namely Sequential Quadratic Programming (SQP) and Interior Point Method (IPM). As a benchmark, we solve different motion tasks on an underactuated and non-minimal-phase ball-balancing robot with a 10 dimensional state space and 3 dimensional input space. Additionally, we validate the results on a simulated 3D quadrotor. Finally, as a verification of using direct transcription methods for trajectory optimization on real robots, we present hardware experiments on a motion task including path constraints and actuation limits.

math.OC↗