相关论文: Precision Spectroscopy at Heavy Ion Ring Accelerat…
Two-dimensional semiconductors have emerged as a new class of materials for nanophotonics for their strong exciton-photon interaction and flexibility for engineering and integration. Taking advantage of these properties, we engineer an…
The recent WMAP data have confirmed that exotic dark matter together with the vacuum energy (cosmological constant) dominate in the flat Universe. Supersymmetry provides a natural dark matter candidate, the lightest supersymmetric particle…
We study electronic transitions in highly-charged Cf ions that are within the frequency range of optical lasers and have very high sensitivity to potential variations in the fine-structure constant, alpha. The transitions are in the optical…
Theoretical studies of superradiant lasing on optical clock transitions predict a superb frequency accuracy and precision closely tied to the bare atomic linewidth. Such a superradiant laser is also robust against cavity fluctuations when…
Positronium and muonium, as purely leptonic atoms without internal structure, provide ideal systems for high-precision tests of quantum electrodynamics (QED) and measurements of fundamental constants. However, the high velocities of these…
Precision determination of the hyperfine splitting of cadmium ions is essential to study space-time variation of fundamental physical constants and isotope shifts. In this work, we present the precision frequency measurement of the…
Magnetically induced (MI) transitions (F${}_{g}$ = 1 $\rightarrow$ F${}_{e}$= 3) of ${}^{87}$Rb D${}_{2}$ line are among the most promising atomic transitions for applications in laser physics. They reach their maximum intensity in the…
We report the observation of the hyperfine spectrum of the weak P(63)4-4 line of the B-X electronic transition of molecular iodine 127I2 near 652.4 nm, using frequency-modulated saturated absorption spectroscopy. Through the precise…
We have measured the 1S - 2S transition frequency in atomic hydrogen via two photon spectroscopy on a 5.8 K atomic beam. We obtain $f_{1S-2S} = 2 466 061 413 187 035 (10)$ Hz for the hyperfine centroid. This is a fractional frequency…
The presence of a weak second-harmonic field in an intense-laser ionization experiment affects the momentum-resolved electron yield, depending on the relative phase between the $\omega$ and the $2\omega$ component. The proposed two-color…
We present and characterize a laser system for the spectroscopy on highly-charged ^209Bi^82+ ions at a wavelength of 243.87 nm. For absolute frequency stabilization, the laser system is locked to a near-infra-red laser stabilized to a…
We report measurements of absolute transition frequencies and hyperfine coupling constants for the 8S_{1/2}, 9S_{1/2}, 7D_{3/2}, and 7D_{5/2} states in ^{133}Cs vapor. The stepwise excitation through either the 6P_{1/2} or 6P_{3/2}…
Photoabsorption by and fluorescence of the K{\alpha} transitions in highly charged iron ions are essential mechanisms for X-ray radiation transfer in astrophysical environments. We study photoabsorption due to the main K{\alpha} transitions…
The absolute frequency measurement for all of the hyperfine transitions of 6P1/2 -> 7S1/2 using a self-referencing frequency comb is reported. This transition can be used as a bench marker for the accurate atomic wave function, and then…
Using optical Ramsey interferometry, we precisely measure the laser-induced AC-stark shift on the $S_{1/2}$ -- $D_{5/2}$ "quantum bit" transition near 729 nm in a single trapped $^{40}$Ca$^+$ ion. We cancel this shift using an additional…
The nuclear symmetry energy at densities above saturation density ($\rho_0\sim 0.16 fm^{-3}$) is poorly constrained theoretically and very few relevant experimental data exist. Its study is possible through Heavy Ion Collisions (HIC) at…
Absolute transition frequencies of the $2s\,^2{\rm{S}}_{1/2}$ $\rightarrow$ $2p\,^2{\rm{P}}_{1/2,3/2}$ transitions in Be$^+$ were measured with a frequency comb in stable and short-lived isotopes at ISOLDE (CERN) using collinear laser…
We review known and discuss new signatures of high-intensity Compton scattering assuming a scenario where a high-power laser is brought into collision with an electron beam. At high intensities one expects to see a substantial red-shift of…
Transition frequencies and fine-structure splittings of the $2\,{}^3\!S_1 \rightarrow 2\,{}^3\!P_{\!J}$ transitions in helium-like $^{12}\mathrm{C}^{4+}$ were measured by collinear laser spectroscopy on a 1-ppb level. Accuracy is increased…
We investigate if the projected high-precision measurements of the cross section of the Higgsstrahlung process $e^+ e^- \to Zh$ at a future electron-positron collider can be utilised to indirectly probe the fermionic Seesaw models. We…