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View article: DFT Simulated Defect Formation Energies of Thorium-Doped LiCAF and LiSAF
DFT Simulated Defect Formation Energies of Thorium-Doped LiCAF and LiSAF Open
AiiDA Workflow to arrive at defect formation energies of Th:LiCAF and Th:LiSAF. Calculated with VASP. More details at the preprint and the journal article. Dataset for Fig. 1.
View article: Electronic Bridge processes in $^{229}$Th-doped LiCAF and LiSAF
Electronic Bridge processes in $^{229}$Th-doped LiCAF and LiSAF Open
Electronic bridge mechanisms driving the $^{229}$Th nuclear clock transition in the vacuum-ultraviolet-transparent crystals $^{229}$Th:LiCAF (LiCaAlF$_6$) and $^{229}$Th:LiSAF (LiSrAlF$_6$) are investigated theoretically. Due to doping-ind…
View article: Frequency reproducibility of solid-state Th-229 nuclear clocks
Frequency reproducibility of solid-state Th-229 nuclear clocks Open
Solid-state $^{229}$Th nuclear clocks are set to provide new opportunities for precision metrology and fundamental physics. Taking advantage of a nuclear transition's inherent low sensitivity to its environment, orders of magnitude more em…
View article: Laser-induced quenching of the Th-229 nuclear clock isomer in calcium fluoride
Laser-induced quenching of the Th-229 nuclear clock isomer in calcium fluoride Open
The 10-min radiative lifetime of the first excited Th4+229 nuclear state in ionic crystals provides narrow spectroscopic linewidths, enabling the realization of a solid-state nuclear clock. Due to the 4+ noble gas configuration, electronic…
View article: Characterization of the thorium-229 defect structure in CaF<sub>2</sub> crystals
Characterization of the thorium-229 defect structure in CaF<sub>2</sub> crystals Open
Recent advancements in laser excitation of the low-energy thorium-229 ( 229 Th) nuclear isomeric state in calcium fluoride (CaF 2 ) single crystals render this system a promising candidate for a solid-state nuclear clock. Nonetheless, the …
View article: Radiative decay of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mmultiscripts><mml:mi>Th</mml:mi><mml:mprescripts/><mml:none/><mml:mrow><mml:mn>229</mml:mn><mml:mi>m</mml:mi></mml:mrow></mml:mmultiscripts></mml:math> nuclear clock isomer in different host materials
Radiative decay of the nuclear clock isomer in different host materials Open
A comparative vacuum ultraviolet spectroscopy study conducted at ISOLDE-CERN of the radiative decay of the Th229m nuclear clock isomer embedded in different host materials is reported. The ratio of the number of radiative decay photons and…
View article: Laser-Induced Quenching of the Th-229 Nuclear Clock Isomer in Calcium Fluoride
Laser-Induced Quenching of the Th-229 Nuclear Clock Isomer in Calcium Fluoride Open
The 10-minute radiative lifetime of the first excited $^{229}$Th$^{4+}$ nuclear state in ionic crystals provides narrow spectroscopic linewidths, enabling the realization of a solid-state nuclear clock. Due to the 4+ noble gas configuratio…
View article: Effects of Thickness and Grain Size on Harmonic Generation in Thin AlN Films
Effects of Thickness and Grain Size on Harmonic Generation in Thin AlN Films Open
High-harmonic generation from solid films is an attractive method for converting infrared laser pulses to ultraviolet and vacuum ultraviolet wavelengths and for examining the films using the generation process. In this work, AlN thin films…
View article: An Embedding Cluster Approach for Accurate Electronic Structure Calculations of (229)Th:CaF2
An Embedding Cluster Approach for Accurate Electronic Structure Calculations of (229)Th:CaF2 Open
Building on recent advances of the embedded cluster approach combined with multiconfigurational theory, this work investigates the electronic states in thorium-doped CaF2 crystals. Th:CaF2 is currently establishing as a promising material …
View article: Temperature sensitivity of a Thorium-229 solid-state nuclear clock
Temperature sensitivity of a Thorium-229 solid-state nuclear clock Open
Quantum state-resolved spectroscopy of the low energy thorium-229 nuclear transition was recently achieved. The five allowed transitions within the electric quadrupole structure were measured to the kilohertz level in a calcium fluoride ho…
View article: Radiative Decay of the $^{229m}$Th Nuclear Clock Isomer in Different Host Materials
Radiative Decay of the $^{229m}$Th Nuclear Clock Isomer in Different Host Materials Open
A comparative vacuum ultraviolet spectroscopy study conducted at ISOLDE-CERN of the radiative decay of the $^{229m}$Th nuclear clock isomer embedded in different host materials is reported. The ratio of the number of radiative decay photon…
View article: Frequency ratio of the $^{229\mathrm{m}}$Th nuclear isomeric transition and the $^{87}$Sr atomic clock
Frequency ratio of the $^{229\mathrm{m}}$Th nuclear isomeric transition and the $^{87}$Sr atomic clock Open
Optical atomic clocks$^{1,2}$ use electronic energy levels to precisely keep track of time. A clock based on nuclear energy levels promises a next-generation platform for precision metrology and fundamental physics studies. Thorium-229 nuc…
View article: Laser Excitation of the Th-229 Nucleus
Laser Excitation of the Th-229 Nucleus Open
The 8.4 eV nuclear isomer state in Th-229 is resonantly excited in Th-doped CaF2 crystals using a tabletop tunable laser system. A resonance fluorescence signal is observed in two crystals with different Th-229 dopant concentrations, while…
View article: Photoexcitation of the $^{229}$Th nuclear clock transition using twisted light
Photoexcitation of the $^{229}$Th nuclear clock transition using twisted light Open
The $^{229}$Th nucleus has a unique transition at only 8 eV which could be used for a novel nuclear clock. We investigate theoretically the prospects of driving this transition with vortex light beams carrying orbital angular momentum. Num…
View article: Compact tunable 80 MHz repetition rate vacuum ultraviolet light source up to 10 eV: intracavity high harmonic generation by nonlinear reflection on a AlN nanofilm in a mode locked Ti:sapphire oscillator
Compact tunable 80 MHz repetition rate vacuum ultraviolet light source up to 10 eV: intracavity high harmonic generation by nonlinear reflection on a AlN nanofilm in a mode locked Ti:sapphire oscillator Open
We report the realization of an intra-oscillator high harmonic source based on a Kerr lens mode locked Ti:sapphire laser running at 80 MHz repetition rate. A nonlinear medium consisting of an AlN nanofilm on a thin sapphire substrate is pl…
View article: Optical transmission enhancement of ionic crystals via superionic fluoride transfer: Growing VUV-transparent radioactive crystals
Optical transmission enhancement of ionic crystals via superionic fluoride transfer: Growing VUV-transparent radioactive crystals Open
The 8−eV first nuclear excited state in Th229 is a candidate for implementing a nuclear clock. Doping Th229 into ionic crystals such as CaF2 is expected to suppress nonradiative decay, enabling nuclear spectroscopy and the realization of a…
View article: Optical Transmission Enhancement of Ionic Crystals via Superionic Fluoride Transfer: Growing VUV-Transparent Radioactive Crystals
Optical Transmission Enhancement of Ionic Crystals via Superionic Fluoride Transfer: Growing VUV-Transparent Radioactive Crystals Open
The 8 eV first nuclear excited state in $^{229}$Th is a candidate for implementing an nuclear clock. Doping $^{229}$Th into ionic crystals such as CaF$_2$ is expected to suppress non-radiative decay, enabling nuclear spectroscopy and the r…
View article: Integrating Superregenerative Principles in a Compact, Power-Efficient NMR/NQR Spectrometer: A Novel Approach with Pulsed Excitation
Integrating Superregenerative Principles in a Compact, Power-Efficient NMR/NQR Spectrometer: A Novel Approach with Pulsed Excitation Open
We present a new approach to Nuclear Quadrupole Resonance (NQR)/Nuclear Magnetic Resonance (NMR) spectroscopy, the Damp-Enhanced Superregenerative Nuclear Spin Analyser (DESSA). This system integrates Superregenerative principles with puls…
View article: Probing nonperturbative third and fifth harmonic generation on silicon without and with thermal oxide layer
Probing nonperturbative third and fifth harmonic generation on silicon without and with thermal oxide layer Open
We examine Si with and without additional SiO 2 thin film coating as a candidate for producing powerful 3rd and 5th harmonics of Ti:sapphire laser pulses for future spectroscopic application. Polarization rotation experiments have been per…
View article: Th:LiCAF DFT Relaxations
Th:LiCAF DFT Relaxations Open
This dataset was generated with VASP and contains OUTCAR files for 1625 relaxations. The paper for this work was published in Adv. Theory Simul. (2022). Relaxations in the folder "not_converged" did not reach the convergence criterion for …
View article: Th:LiCAF DFT Relaxations
Th:LiCAF DFT Relaxations Open
This dataset was generated with VASP and contains OUTCAR files for 1625 relaxations. The paper for this work was published in Adv. Theory Simul. (2022). Relaxations in the folder "not_converged" did not reach the convergence criterion for …
View article: Nonperturbative Generation of Harmonics by Nanometer-Scale Localized Electronic States on the Surface of Bulk Materials and Nano-Films
Nonperturbative Generation of Harmonics by Nanometer-Scale Localized Electronic States on the Surface of Bulk Materials and Nano-Films Open
The generation of high-order harmonics in solid crystals has received considerable attention recently. Using a driver laser with 0.8 µm wavelength and 28 fs ultrashort pulses, we present experimental results, accompanied with theoretical c…
View article: Growth and characterization of thorium-doped calcium fluoride single crystals
Growth and characterization of thorium-doped calcium fluoride single crystals Open
We have grown $^{232}$Th:CaF$_2$ and $^{229}$Th:CaF$_2$ single crystals for investigations on the VUV laser-accessible first nuclear excited state of $^{229}$Th. To reach high doping concentrations despite the extreme scarcity (and radioac…
View article: Observation of the radiative decay of the ${}^{229}\mathrm{Th}$ nuclear clock isomer
Observation of the radiative decay of the ${}^{229}\mathrm{Th}$ nuclear clock isomer Open
The nucleus of the radioisotope thorium-229 (${}^{229}$Th) features an isomer with an exceptionally low excitation energy that enables direct laser manipulation of nuclear states. For this reason, it is a leading candidate for use in next-…
View article: Band Gap Calculations for Thorium‐Doped LiCAF
Band Gap Calculations for Thorium‐Doped LiCAF Open
The large band gap insulator LiCaAlF 6 (LiCAF) has been proposed as a possible host crystal for future realizations of a solid‐state based thorium‐229 nuclear clock, due to its excellent optical transmission in the vacuum ultraviolet range…
View article: Ab-Initio Study of Calcium Fluoride Doped with Heavy Isotopes
Ab-Initio Study of Calcium Fluoride Doped with Heavy Isotopes Open
Precision laser spectroscopy of the 229-thorium nuclear isomer transition in a solid-state environment would represent a significant milestone in the field of metrology, opening the door to the realization of a nuclear clock. Working towar…