Publications

I. Doran, L. Jeckel, M. Beyer, Ch. Jungen, F. Merkt (2026). Precision Spectroscopy of the Fine and Hyperfine Structures of High Molecular Rydberg-Stark States: Metrology of Molecular Hydrogen Ions. Phys. Rev. Lett. 137, 063001 (2026).

I. Doran, L. Jeckel, M. Beyer, Ch. Jungen, F. Merkt (2026). Stark effect in molecular Rydberg states: Calculation of Rydberg-Stark manifolds of $\mathrm{H}_2$ and $\mathrm{D}_2$ including fine and hyperfine structures. Phys. Rev. A 113, 062812 (2026).

D. Knapp, M. Beyer (2026). State-selected preparation of diatomic molecular ions for precision measurements in radio-frequency traps. Molecular Physics, e2652534 (2026).

L. Verdegay, B. Zeng, D. Knapp, J. C. Roth, M. Beyer (2025). Laser cooling Rydberg molecules—a detailed study of the helium dimer. New J. Phys. 27, 093201 (2025).

K.-F. Lai, W. Ubachs, M. Beyer (2025). Precision measurement of the last bound states in $\mathrm{H}_2$ and determination of the $\mathrm{H}+\mathrm{H}$ scattering length. Phys. Rev. A 111, 022803 (2025).

I. Doran, M. Beyer, F. Merkt (2024). Rotational and spin-rotational level structure of para-$\mathrm{H}_2^+$ from high-resolution multichannel-quantum-defect-theory-assisted Rydberg-state spectroscopy. Phys. Rev. A 110, 062804 (2024).

I. Doran, N. Hölsch, M. Beyer, F. Merkt (2024). Zero-Quantum-Defect Method and the Fundamental Vibrational Interval of $\mathrm{H}_2^+$. Phys. Rev. Lett. 132, 073001 (2024).

N. Hölsch, I. Doran, F. Merkt, J. Hussels, C.-F. Cheng, E. J. Salumbides, H. L. Bethlem, K. S. E. Eikema, M. Beyer, W. Ubachs, Ch. Jungen (2023). Ionization and dissociation energies of HD and dipole-induced g/u-symmetry breaking. Phys. Rev. A 108, 022811 (2023).

C. Roth, A. Martínez de Velasco, E. L. Gründeman, M. Collombon, M. Beyer, V. Barbé, K. S. E. Eikema (2023). High-precision Ramsey-comb spectroscopy on molecular deuterium for tests of molecular quantum theory. Mol. Phys. e2211405 (2023).

K.-F. Lai, M. Beyer, W. Ubachs (2023). Spectroscopic study of the F outer well state in H$_2$, HD and D$_2$. J. Mol. Spectrosc. 393, 111778 (2023).

D. Ochoa, M. Beyer (2022). Black-body radiation-induced photodissociation and population redistribution of weakly bound states in H$_2^+$. Mol. Phys. , e2133750 (2022).

N. Hölsch, I. Doran, M. Beyer, F. Merkt (2022). Precision millimetre-wave spectroscopy and calculation of the Stark manifolds in high Rydberg states of para-H$_2$. J. Mol. Spectrosc. 387, 111648 (2022).

M. Beyer, F. Merkt (2022). Structure and dynamics of HD$^+$ in the vicinity of the H$^+$ + D and D$^+$ + H dissociation thresholds: Feshbach resonances and the role of g/u-symmetry breaking. Mol. Phys. , e2048108 (2022).

J. Hussels, N. Hölsch, C.-F. Cheng, E. J. Salumbides, H. L. Bethlem, K. S. E. Eikema, Ch. Jungen, M. Beyer, F. Merkt, W. Ubachs (2022). Improved ionization and dissociation energies of the deuterium molecule. Phys. Rev. A 105, 022820 (2022).

K.-F. Lai, E. J. Salumbides, M. Beyer, W. Ubachs (2021). Precision measurement of quasi-bound resonances in H$_2$ and the H+H scattering length. Mol. Phys. e2018063 (2021).

K.-F. Lai, E. J. Salumbides, W. Ubachs, M. Beyer (2021). Shape Resonances in H$_2$ as Photolysis Reaction Intermediates. Phys. Rev. Lett. 127, 183001 (2021).

M. Beyer, J. C. Roth, E. Edwards, D. DeMille (2021). Frequency-doubled Nd:YAG MOPA laser system with programmable rectangular pulses up to 200 microseconds. Optics Express 29, 20370 (2021).

K.-F. Lai, M. Beyer, E. J. Salumbides, W. Ubachs (2021). Photolysis Production and Spectroscopic Investigation of the Highest Vibrational States in H$_2$ (X $v = 13, 14$). J. Phys. Chem. A 125, 1221 (2021).

M. Beyer, N. Hölsch, J. Hussels, C.-F. Cheng, E. J. Salumbides, K. S. E. Eikema, W. Ubachs, Ch. Jungen, F. Merkt (2019). Determination of the Interval between the Ground States of Para- and Ortho-H$_2$. Phys. Rev. Lett. 123, 163002 (2019).

N. Hölsch, M. Beyer, E. J. Salumbides, K. S. E. Eikema, W. Ubachs, Ch. Jungen, F. Merkt (2019). Benchmarking Theory with an Improved Measurement of the Ionization and Dissociation Energies of H$_2$. Phys. Rev. Lett. 122, 103002 (2019).

M. Beyer, F. Merkt (2018). Hyperfine-interaction-induced g/u mixing and its implication on the existence of the first excited vibrational level of the A$^+$ state of H$_2^+$ and on the scattering length of the H + H$^+$ collision. J. Chem. Phys. 149, 214301 (2018).

N. Hölsch, M. Beyer, F. Merkt (2018). Nonadiabatic effects on the positions and lifetimes of the low-lying rovibrational levels of the GK and H states of H$_2$. Phys. Chem. Chem. Phys. 20, 26837 (2018).

M. Beyer, F. Merkt (2018). Half-Collision Approach to Cold Chemistry: Shape Resonances, Elastic Scattering, and Radiative Association in the H$^+$ + H and D$^+$ + D Collision Systems. Phys. Rev. X 8, 031085 (2018).

M. Beyer, F. Merkt (2018). Communication: Heavy-Rydberg states of HD and the electron affinity of the deuterium atom. J. Chem. Phys. 149, 031102 (2018).

C.-F. Cheng, J. Hussels, M. Niu, H. L. Bethlem, K. S. E. Eikema, E. J. Salumbides, W. Ubachs, M. Beyer, N. Hölsch, J. A. Agner, F. Merkt, L.-G. Tao, S.-M. Hu, Ch. Jungen (2018). Dissociation Energy of the Hydrogen Molecule at $10^{-9}$ Accuracy. Phys. Rev. Lett. 121, 013001 (2018).

M. Beyer, N. Hölsch, J. A. Agner, J. Deiglmayr, H. Schmutz, F. Merkt (2018). Metrology of high-n Rydberg states of molecular hydrogen with $10^{-10}$ accuracy. Phys. Rev. A 97, 012501 (2018).

M. Beyer, F. Merkt (2017). High-resolution photoelectron spectroscopy and calculations of the highest bound levels of D$_2^+$ below the first dissociation threshold. J. Phys. B: At. Mol. Opt. Phys. 50, 154005 (2017).

M. Beyer, F. Merkt (2016). Structure and dynamics of H$_2^+$ near the dissociation threshold: A combined experimental and computational investigation. J. Mol. Spectrosc. 330, 147 (2016).

M. Beyer, F. Merkt (2016). Observation and Calculation of the Quasibound Rovibrational Levels of the Electronic Ground State of H$_2^+$. Phys. Rev. Lett. 116, 093001 (2016).

Ch. Haase, M. Beyer, Ch. Jungen, F. Merkt (2015). The fundamental rotational interval of para-H$_2^+$ by MQDT-assisted Rydberg spectroscopy of H$_2$. J. Chem. Phys. 142, 064310 (2015).

D. Sprecher, M. Beyer, F. Merkt (2013). Precision measurement of the ionisation energy of the 3dσ GK state of H$_2$. Mol. Phys. 111(14-15), 2100 (2013).

D. Sprecher, M. Beyer, F. Merkt (2013). Precision measurements of ionization and dissociation energies by extrapolation of Rydberg series: From H$_2$ to larger molecules. Chimia 67(4), 257-261 (2013).