Related papers: Direct observation of a highly forbidden optical t…
We present the observation of three semi-forbidden transitions in singly-ionized ytterbium from the metastable $^{2}\mathrm{F}^o_{7/2}$ state. Owing to the long lifetimes of both the upper and lower states involved, these transitions are…
Solid-state emitters with atom-like optical and magnetic transitions are highly desirable for efficient and scalable quantum state engineering and information processing. Quantum dots, color centers and impurities embedded in inorganic…
Forbidden atomic transitions provide some of the most stringent low-energy tests of physics beyond the Standard Model, with sensitivity set by the interplay between the sought-for signals and systematics suppressed by symmetry. Here we…
Direct evidence of excitation of the 5p3/2 -> 6p3/2 electric dipole forbidden transition in atomic rubidium is presented. The experiments were performed in a room temperature rubidium cell with continuous wave extended cavity diode lasers.…
We present the first systematic calculation of the electric dipole forbidden transitions in the homonuclear molecular ion H$_2^+$. We get that the transition rate from the ground "ortho" $(v\!=\!0,N\!=\!1,J\!=\!1/2)$ state to the ground…
We present observations of VUV transitions between doubly excited sextet states in O IV, F V and Ne VI. Spectra were produced by collisions of an O+ beam with a solid carbon target. We also studied spectra obtained previously of F V and Ne…
Time-resolved emission, excitation as well as emission decay curves of CaF$_2$, SrF$_2$, BaF$_2$ doped with HoF$_3$ were investigated. Most intensive emission bands near 168 nm, having long decay time, belong to spin-forbidden transitions…
Direct frequency comb spectroscopy of trapped ions is demonstated for the first time. It is shown that the 4s^2S_(1/2)-4p^2P_(3/2) transition in calcium ions can be excited directly with a frequency comb laser that is upconverted to 393 nm.…
The photo-induced band structure variation of a rare-earth-based semiconductor, samarium monosulfide (SmS), was investigated using high-harmonic-generation laser-based time-resolved photoelectron spectroscopy. A nonlinear photo-induced band…
We present the detection of the highly forbidden $2^{3\!}S_1 \rightarrow 3^{3\!}S_1$ atomic transition in helium, the weakest transition observed in any neutral atom. Our measurements of the transition frequency, upper state lifetime, and…
LiSrAlF$_6$ crystals doped with $^{229}$Th are used in a laser-based search for the nuclear isomeric transition. Two spectroscopic features near the nuclear transition energy are observed. The first is a broad excitation feature that…
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…
The electronic, laser-induced fluorescence spectrum of the $B^2\Sigma^+\leftarrow X^2\Sigma^+$ transition in $^{28}$Si$^{16}$O$^+$ and $^{29}$Si$^{16}$O$^+$ has been recorded in a cryogenic buffer gas cell at $\approx$ 100 K. Molecular…
We study the occurrence of long-lived metastable states in the 4f$^{13}$5d6s electron configuration of Yb$^+$. By optical pumping of a single trapped ion on the $^2F^\text{o}_{7/2}\rightarrow (7/2,0)_{7/2}$ transition at 377.5 nm, we…
By experimental exploration of the so-called $\lambda $-Zeeman technique based on Rb nano-cell use we reveal for the first time a strong modification of the probability of the $^{87}$Rb, $D_2$ line $F_g=1 \rightarrow F_e=0, 1, 2, 3$ atomic…
We present VUV observations of transitions between doubly excited sextet states in O3+, F4+ and Ne5+. Spectra were produced by collisions of an oxygen, uorine and neon beam with a nitrogen gas jet target. Prepared beam-gas experiment yields…
Sr2IrO4 exhibits a novel insulating state assisted by spin-orbit interactions. A series of polycrystalline samples of Sr2-xIrO4 have been synthesized. It is found that deep Sr-vacancies of Sr2-xIrO4 greatly reduce the rotation of IrO6…
We present the first evidence of excitation of the $5p_{3/2} \rightarrow 6p_{1/2}$ electric dipole-forbidden transition in atomic rubidium. The experiments were carried out in a rubidium vapor cell using Doppler-free optical-optical…
We present a theoretical investigation of the chemical reaction SrF + SrF $\rightarrow$ products, focusing on reactions at ultralow temperatures. We find that bond swapping, SrF + SrF $\rightarrow$ Sr$_2$ + F$_2$, is energetically forbidden…
Optically induced ultrafast electronic excitations with sufficiently long lifetimes may cause strong effects on phase transitions like structural and nonmetal to metal ones. Examples are transitions diamond to graphite, graphite to…