The theory of direct laser excitation of nuclear transitions

Abstract

A comprehensive theoretical study of direct laser excitation of a nuclear state based on the density matrix formalism is presented. The nuclear clock isomer ${}^{229\text{m}}$Th is discussed in detail, as it could allow for direct laser excitation using existing technology and provides the motivation for this work. The optical Bloch equations are derived for the simplest case of a pure nuclear two-level system and for the more complex cases taking into account the presence of magnetic sub-states, hyperfine-structure and Zeeman splitting in external fields. Nuclear level splitting for free atoms and ions as well as for nuclei in a solid-state environment is discussed individually. Based on the obtained equations, nuclear population transfer in the low-saturation limit is reviewed. Further, nuclear Rabi oscillations, power broadening and nuclear two-photon excitation are considered. Finally, the theory is applied to the special cases of ${}^{229\text{m}}$Th and ${}^{235\text{m}}$U, being the nuclear excited states of lowest known excitation energies. The paper aims to be a didactic review with many calculations given explicitly.

References in corpus (39)

• Atomic clock performance beyond the geodetic limit
• An ${}^{27}$Al${}^{+}$ quantum-logic clock with systematic uncertainty below $10^{-18}$
• Hunting for topological dark matter with atomic clocks
• Direct Frequency Comb Spectroscopy in the Extreme Ultraviolet
• A Single-Ion Nuclear Clock for Metrology at the 19th Decimal Place
• Atomic Clocks for Geodesy
• Direct detection of the 229Th nuclear clock transition
• Enhanced effect of temporal variation of the fine structure constant in diatomic molecules
• Energy of the ${}^{229}$Th nuclear clock transition
• Laser spectroscopic characterization of the nuclear clock isomer ${}^{229m}$Th
• Wigner Crystals of 229Th for Optical Excitation of the Nuclear Isomer
• Proposal for a Nuclear Gamma-Ray Laser of Optical Range
• Nuclear quantum optics with x-ray laser pulses
• Performance of a 229 Thorium solid-state nuclear clock
• Lifetime measurement of the ${}^{229}$Th nuclear isomer
• Excitation of the isomeric ^{229m}Th nuclear state via an electronic bridge process in ^{229}Th^+
• Phase-matched extreme-ultraviolet frequency-comb generation
• X-ray pumping of the Th-229 nuclear clock isomer
• Radiative lifetime and energy of the low-energy isomeric level in ${}^{229}$Th
• Reduced transition probabilities for the gamma decay of the 7.8 eV isomer in ${}^{229}$Th
• Lasers as a Bridge between Atomic and Nuclear Physics
• Effect of atomic electrons on 7.6 eV nuclear transition in ${}^{229}$Th${}^{3+}$
• Electric dipole-forbidden nuclear transitions driven by super-intense laser fields
• A laser excitation scheme for ${}^{229\text{m}}$Th
• Nuclear coherent population transfer with x-ray laser pulses
• On an attempt to optically excite the nuclear isomer in Th-229
• Magnetic dipole and electric quadrupole moments of the 229Th nucleus
• Broadband high-resolution x-ray frequency combs
• Theoretical predictions for the magnetic dipole moment of ${}^{229m}$Th
• Resonance ionization spectroscopy of thorium isotopes - towards a laser spectroscopic identification of the low-lying 7.6 eV isomer of Th-229
• A three-beam setup for coherently controlling nuclear state population
• The electric quadrupole channel of the 7.8 eV ${}^{229}\mathrm{Th}$ transition
• Towards a 229Th-based nuclear clock
• Excitation of the ${}^{229}$Th nucleus via a two-photon electronic transition
• Resonant electronic-bridge excitation of the U-235 nuclear transition in ions with chaotic spectra
• Nuclear Isomer Excitation in 229Th Atom by Super-Intense Laser Field
• Collective effects in ${}^{229}$Th-doped crystals
• The concept of laser-based conversion electron Mössbauer spectroscopy for a precise energy determination of ${}^{229m}$Th
• Quantum interference effects in an ensemble of ${}^{229}$Th nuclei interacting with coherent light

Cited by in corpus (9)

• The ${}^{229}$Th isomer: prospects for a nuclear optical clock
• A scheme for excitation of thorium-229 nuclei based on the electronic bridge excitaion
• ${}^{229}$Th Nuclear Spectroscopy in an Opaque Material: Laser-Based Conversion Electron Mössbauer Spectroscopy of ${}^{229}$ThO${}_2$
• Interaction of vector light beams with atoms exposed to a time-dependent magnetic field
• A continuous-wave vacuum ultraviolet laser for the nuclear clock
• Interaction of a Poincaré beam with optically polarized atoms in the presence of constant magnetic field
• High-fidelity Nuclear Coherent Population Transfer via the Mixed-State Inverse Engineering
• A new scheme for isomer pumping and depletion with high-power lasers
• State-Selective Ionization and Trapping of Single H${}_2^{+}$ Ions with (2+1) Multiphoton Ionization