相关论文: Quadruply Ionized Barium as a Candidate for a High…

A transportable optical clock refer to the $4s^2S_{1/2}-3d^2D_{5/2}$ electric quadrupole transition at 729 nm of single $^{40}Ca^+$ trapped in mini Paul trap has been developed. The physical system of $^{40}Ca^+$ optical clock is…

Our study is motivated by the prospect of several metastable states in the Sb$ ^{+} $, Au$ ^{+} $, and Hg$ ^{2+} $ ions being used as possible candidates for optical clocks. We calculate several atomic properties relevant to the development…

Highly charged ions (HCIs) are insensitive to external perturbations and are attractive for the development of ultrastable clocks. However, only a few HCI candidates are known to provide optical clock transitions. In this Letter, we show…

We report for the first time, laser spectroscopy of the 1S0 - 3P0 clock transition in 27Al+. A single aluminum ion and a single beryllium ion are simultaneously confined in a linear Paul trap, coupled by their mutual Coulomb repulsion. This…

A systematic study of Ca+ atomic properties is carried out using high-precision relativistic all-order method where all single, double, and partial triple excitations of the Dirac-Fock wave functions are included to all orders of…

We propose a novel class of atomic clocks based on highly charged ions. We consider highly-forbidden laser-accessible transitions within the $4f^{12}$ ground-state configurations of highly charged ions. Our evaluation of systematic effects…

Derivations for the higher tensor components of the quadrupole polarizabilities are given and their values for the metastable states of the Ca$^+$, Sr$^+$ and Ba$^+$ alkaline earth-metal ions are estimated. We also give the scalar…

Multi-ion optical clocks offer the possibility of overcoming the low signal-to-noise ratio of single-ion clocks, while still providing low systematic uncertainties. We present simultaneous spectroscopy of up to four ${}^{115}$In${}^+$ clock…

With the advent of optical clocks featuring fractional frequency uncertainties on the order of $10^{-17}$ and below, new applications such as chronometric levelling with few-cm height resolution emerge. We are developing a transportable…

We examine energy level-crossings of fine-structure (FS) levels in the heavier highly charged ions (HCIs) with $d^6$ and $d^8$ configurations. From the analysis, we find that some of these HCIs are tailor-made for atomic clocks with quality…

We study a wide range of neutral atoms and ions suitable for ultra-precise atomic optical clocks with naturally suppressed black body radiation shift of clock transition frequency. Calculations show that scalar polarizabilities of clock…

Highly charged ions of heavy actinides from uranium to einsteinium are studied theoretically to find optical transitions sensitive to the variation of the fine structure constant. A number of promising transitions have been found in ions…

Motivated by recent experimental advances, including the ongoing development of an optical atomic clock in singly ionised radium, we perform a detailed theoretical characterisation of Ra+ and its lighter analogue, Ba+. Both ions are of…

An atom exposed to an electric field will experience Stark shifts of its internal energy levels, proportional to their polarizabilities. In optical frequency metrology, the Stark shift due to background black-body radiation (BBR) modifies…

Today's most accurate clocks are based on laser spectroscopy of electronic transitions in single trapped ions and feature fractional frequency uncertainties below $1\times10^{-18}$. Scaling these systems to multiple, simultaneously…

We present a compact, long-term nearly continuous operation of a room-temperature Ca$^+$ optical clock setup towards a transportable clock, achieving an overall systematic uncertainty of $4.8\times 10^{-18}$ and an uptime rate of 97.8% over…

We propose that a nuclear clock based on the Th V ion can surpass the accuracy of clocks built with other thorium ions. The Th$^{4+}$ ion has a rigid closed-shell core with zero total electron angular momentum, suppressing frequency shifts…

An ultra-stable optical clock based on coherent population trapping effect of alkaline-earth ions, such as Ca$^+$, Sr$^+$, Ba$^+$, is analyzed here. The proposed transitions use the odd isotopes, so that the frequency shift is insensitive…

The Ni$^{12+}$ ion features an electronic transition with a natural width of only 8 mHz, allowing for a highly stable optical clock. We predict that the energy of this strongly forbidden $3s^2 3p^4\, ^3\!P_2 \rightarrow 3s^2 3p^4 \,…

Appraising the projected $10^{-18}$ fractional uncertainty in the optical frequency standards using singly ionized ions, we estimate the black-body radiation (BBR) shifts due to the magnetic dipole (M1) and electric quadrupole (E2)…