0000000000170536
AUTHOR
O. Docenko
Spectroscopic data, spin-orbit functions, and revised analysis of strong perturbative interactions for theA 1Σ+andb 3Πstates of RbCs
The current interest in producing ultracold RbCs molecules by optical excitation from weakly bound Feshbach resonances and stimulated decay to the absolute ground state requires detailed analyses of the intermediate excited states. In this study, we present two sets of experimental Fourier-transform spectroscopic data of the $A{ }^{1}{\ensuremath{\Sigma}}^{+}$-$b{ }^{3}\ensuremath{\Pi}$ complex. The $A$-$b$ mixed vibrational levels are the most likely candidates to be intermediates in the molecular formation. The more recent and more accurate data set is from mixed $A$-$b\ensuremath{\rightarrow}X$ transitions, while the second is derived in large part from $(4){ }^{1}{\ensuremath{\Sigma}}^{…
Potentials for modeling cold collisions between Na (3S) and Rb (5S) atoms
The experimental characterization of the electronic states correlated to the asymptote of ground state Na (3S) and Rb (5S) atoms was expanded by spectroscopic data on $a\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Sigma}^{+}$ state levels using a high resolution Fourier transform spectroscopy technique. The hyperfine splitting of the $a\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Sigma}^{+}$ state levels was partially resolved and analyzed for both $\mathrm{Na}\phantom{\rule{0.2em}{0ex}}^{85}\mathrm{Rb}$ and $\mathrm{Na}\phantom{\rule{0.2em}{0ex}}^{87}\mathrm{Rb}$ isotopomers. Transitions to high lying levels of the $a\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Sigma}^{+}$ and $X\phantom{\rul…
High resolution spectroscopy and potential determination of the (3)1Pi state of NaCs.
The (3)(1)Pi state of the NaCs molecule was studied by high resolution Fourier-transform spectroscopy. The (3)(1)Pi--X (1)Sigma(+) laser induced fluorescence was excited by an Ar(+) ion laser or by a single-mode frequency-doubled cw Nd:YAG laser. The presence of argon buffer gas yielded rich rotational relaxation spectra allowing to enlarge the data set for the (3)(1)Pi state term values, as well as to observe Lambda splittings in a wide range of vibrational (v(')) and rotational (J(')) quantum numbers. The data field includes about 820 energy levels of (3)(1)Pi NaCs in the range from v(')=0 to 37 and from J(')=3 to 190, which corresponds to ca. 95% of the potential well depth. Direct fit o…
Fourier-transform spectroscopy and description of low-lying energy levels in the B(1)(1)Π state of RbCs.
The Fourier transform spectrometer with resolution of 0.03 cm(-1) was applied to disperse the diode laser induced B(1)(1)Π → X(1)Σ(+) fluorescence spectra of the RbCs molecule in a heat pipe. The presence of buffer gas (Ar) produced in the spectra the dense pattern of collision-induced rotation relaxation lines, thus enlarging the B(1)(1)Π data set, allowing to determine the Λ-splitting constants and to reveal numerous local perturbations. In total, 2664 term values for (85)Rb(133)Cs and (87)Rb(133)Cs in the energy range from 13,770 to 15,200 cm(-1) were obtained with accuracy about 0.01 cm(-1). A pointwise potential energy curve (PEC) based on inverted perturbation approach was constructed…
Experimental studies of the NaRb ground-state potential up to thev″=76level
Laser induced fluorescence spectra of the C {sup 1}{sigma}{sup +}-X {sup 1}{sigma}{sup +} system of {sup 23}Na{sup 85}Rb and {sup 23}Na{sup 87}Rb have allowed vibrational levels of the electronic ground state up to v{sup ''}=76, spanning 99.85% of the potential well to be observed. The ground-state term values have been fitted to a Dunham polynomial expansion, and also to a direct modified Lennard-Jones (MLJ) potential. The analytical MLJ construction allowed us to match previous measured term values for v{sup ''}{<=}30 with long-range behavior of the potential through the intermediate internuclear distance region covered by the present investigation.
Extended Fourier-transform spectroscopy studies and deperturbation analysis of the spin-orbit coupled A1Σ+ and b3Π states in RbCs.
The article presents a study of the strongly spin-orbit coupled singlet A(1)Σ(+) and triplet b(3)Π states of the RbCs molecule, which provide an efficient optical path to transfer ultracold molecules to their rovibrational ground state. Fourier-transform A(1)Σ(+) - b(3)Π → X(1)Σ(+) and (4)(1)Σ(+) → A(1)Σ(+) - b(3)Π laser-induced fluorescence (LIF) spectra were recorded for the natural mixture of the (85)Rb(133)Cs and (87)Rb(133)Cs isotopologues produced in a heat pipe oven. Overall 8730 rovibronic term values of A(1)Σ(+) and b(3)Π states were determined with an uncertainty of 0.01 cm(-1) in the energy range [9012, 14087] cm(-1), covering rotational quantum numbers J ∈ [6, 324]. An energy-ba…
The coupling of the X1Σ+and a3Σ+states of the atom pair Na + Cs and modelling cold collisions
The states X1?+ and a3?+ correlated to the ground-state asymptote of Na (3s) and Cs (6s) atoms have been experimentally investigated using high resolution Fourier-transform spectroscopy. The hyperfine splitting of the a3?+ state levels is partially resolved. Transitions to asymptotic vibrational levels of the a3?+ and X1?+ states were recorded simultaneously. The joint evaluation of the data of both the a3?+ and the X1?+ states allows us to determine accurate potential energy curves of both electronic states. Coupled-channels calculations are finally applied for deriving long range dispersion parameters and the exchange contribution of the molecular potentials, yielding a reliable descripti…
Spectroscopic studies of the(4)1Σ+state of RbCs and modeling of the optical cycle for ultracoldX 1Σ+(v=0,J=0)molecule production
We performed high-resolution Fourier-transform spectroscopy measurements and direct-potential-fit of the shelflike RbCs $(4){\phantom{\rule{0.16em}{0ex}}}^{1}{\ensuremath{\Sigma}}^{+}$ state. Overall, 2317 rovibronic ${v}^{\ensuremath{'}},{J}^{\ensuremath{'}}$ term values with ${v}^{\ensuremath{'}}\ensuremath{\in}[3,88]$, ${J}^{\ensuremath{'}}\ensuremath{\in}[7,276]$ were obtained with accuracy 0.01 cm${}^{\ensuremath{-}1}$ from the $(4){\phantom{\rule{0.16em}{0ex}}}^{1}{\ensuremath{\Sigma}}^{+}\ensuremath{\rightarrow}X{\phantom{\rule{0.16em}{0ex}}}^{1}{\ensuremath{\Sigma}}^{+},a{\phantom{\rule{0.16em}{0ex}}}^{3}{\ensuremath{\Sigma}}^{+}$ laser-induced fluorescence (LIF) spectra. The mass-i…
Coupling of theXΣ+1andaΣ+3states ofKRb
A comprehensive study of the electronic states at the $4s+5s$ asymptote in $\mathrm{KRb}$ is presented. Abundant spectroscopic data on the $a\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Sigma}^{+}$ state were collected by Fourier-transform spectroscopy, which allows one to determine an accurate experimental potential energy curve up to $14.8\phantom{\rule{0.3em}{0ex}}\mathrm{\AA{}}$. The existing data set [C. Amiot et al., J. Chem. Phys. 112, 7068 (2000)] on the ground state $X\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+}$ was extended by several additional levels lying close to the atomic asymptote. In a coupled channels fitting routine complete molecular potentials for both electr…
Permanent electric dipoles andΛ-doubling constants in the lowestΠ1states of RbCs
The article presents first experimental data on the Stark induced $e\text{\ensuremath{-}}f$ mixing in the $(4)\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Pi}$ state of the $^{85}\mathrm{Rb}^{133}\mathrm{Cs}$ molecule, as well as the ab initio calculations of permanent electric dipole moments $(d)$ in the $(1,2,3,4)\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Pi}$ states and $q$ factors in the $(2,4)\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Pi}$ states. The appearance of the ``forbidden'' lines in the laser-induced $(4)\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Pi}\ensuremath{\rightarrow}X\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Pi}^{+}$ fluorescence spectrum in the presence of an elect…
Deperturbation treatment of theAΣ+1–bΠ3complex of NaRb and prospects for ultracold molecule formation inXΣ+1(v=0;J=0)
High resolution Fourier transform spectra (FTS) of laser induced fluorescence (LIF) of $C\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+};D\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Pi}\ensuremath{\rightarrow}A\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+}--b\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Pi}$ and $A\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+}--b\phantom{\rule{0.2em}{0ex}}^{3}\ensuremath{\Pi}\ensuremath{\rightarrow}X\phantom{\rule{0.2em}{0ex}}^{1}\ensuremath{\Sigma}^{+}$ transitions in ${\mathrm{Na}}^{85}\mathrm{Rb}$ and ${\mathrm{Na}}^{87}\mathrm{Rb}$ were obtained. An analysis of the direct LIF spectra together with the rotational relaxation satellite…
Energy and radiative properties of the low-lying NaRb states
D 1 P ‐B 1 P transition dipole moments, as well as nonadiabatic L-uncoupling matrix elements between the examined 1 P and four lowest 1 S 1 states for both 23 Na 85 Rb and 23 Na 87 Rb isotopomers. The relevant MPPT ab initio matrix elements and energy curves were converted by means of the approximate sum rule to radiative lifetimes and L-doubling constants ( q factors! for the particular rovibronic levels of the B 1 P and D 1 P states. The theoretical lifetimes agree well with their experimental counterparts for both B 1 P and D 1 P states. The q factor estimates obtained in the singlet-singlet approximation are in good agreement with the experimental ones for the D 1 P(1<v8<12;7<J8<50) lev…
Singlet and triplet potentials of the ground-state atom pair Rb+Cs studied by Fourier-transform spectroscopy
A comprehensive study of the $X {}^{1}\ensuremath{\Sigma}{}^{+}$ and $a {}^{3}\ensuremath{\Sigma}{}^{+}$ electronic states of the Rb and Cs atom pair in RbCs is presented. Abundant spectroscopic data for the $^{85}\mathrm{Rb}$$^{133}\mathrm{Cs}$ and $^{87}\mathrm{Rb}$$^{133}\mathrm{Cs}$ isotopologues were obtained from Fourier-transform spectra of laser-induced fluorescence (LIF) from the $B {}^{1}\ensuremath{\Pi}$ and $(4){}^{1}\ensuremath{\Sigma}{}^{+}$ states to the $a {}^{3}\ensuremath{\Sigma}{}^{+}$ (4549 transitions) and $X {}^{1}\ensuremath{\Sigma}{}^{+}$ (15 709 transitions) states. The $X {}^{1}\ensuremath{\Sigma}{}^{+}$ state data were complemented by about 15 500 transitions obta…
The coupling of the X$^{1}\Sigma ^{+}$ and a$^{3}\Sigma ^{+}$ states of KRb
A comprehensive study of the electronic states at the 4s+5s asymptote in KRb is presented. Abundant spectroscopic data on the \astate state were collected by Fourier-transform spectroscopy which allow to determine an accurate experimental potential energy curve up to 14.8 \AA . The existing data set (C. Amiot et al. J. Chem. Phys. 112, 7068 (2000)) on the ground state \Xstate was extended by several additional levels lying close to the atomic asymptote. In a coupled channels fitting routine complete molecular potentials for both electronic states were fitted. Along with the line frequencies of the molecular transitions, recently published positions of Feshbach resonances in $^{40}$K and $^{…
The B 1Pi state of NaCs: high resolution laser induced fluorescence spectroscopy and potential construction.
The lowest (1)Pi state of the NaCs molecule, the B(1)(1)Pi state, was studied using a dye laser for inducing fluorescence that was resolved by a high resolution Fourier-transform spectrometer. The presence of argon buffer gas yielded rich rotational relaxation spectra allowing to enlarge the data set for the B(1)(1)Pi state, to obtain Lambda-splittings and to reveal numerous local perturbations. 543 weakly perturbed energy levels for rotational quantum numbers from J(')=5 to 168 and vibrational quantum numbers from v(')=0 to 25, which cover about 87% of the potential well depth, were used for a direct pointwise fit of the potential energy curve applying the inverted perturbation approach me…
Spin-orbit, radial, and angular coupling effects in the NaRb excited states
Spin-orbit, radial, and angular nonadiabatic matrix elements between the lowest excited states of NaRb are evaluated by quasi-relativistic ab initio methods, and the results accompanied by potential curves, permanent and transition moments are compared with experimental data and preceding calculations.
The potential of the ground state of NaRb
The X$^{1}\Sigma ^{+}$ state of NaRb was studied by Fourier transform spectroscopy. An accurate potential energy curve was derived from more than 8800 transitions in isotopomers $^{23}$Na$^{85}$Rb and $^{23}$Na$^{87}$Rb. This potential reproduces the experimental observations within their uncertainties of 0.003 \rcm to 0.007 \rcm. The outer classical turning point of the last observed energy level ($v''=76$, $J''=27$) lies at $\approx 12.4$ \AA, leading to a energy of 4.5 \rcm below the ground state asymptote.