Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userPhotoassociation of rovibrational Rydberg molecules
161
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
In this work we discuss the rotational structure of Rydberg molecules. We calculate the complete wave function in a laboratory fixed frame and derive the transition matrix elements for the pho- toassociation of free ground state atoms. We discuss the implications for the excitation of different rotational states as well as the shape of the angular nuclear wave function. We find a rather com- plex shape and unintuitive coupling strengths, depending on the angular momenta coupling that are relevant for the states. This work explains the different steps to calculate the wave functions and the transition matrix elements in a way, that they can be directly transferred to different molecular states, atomic species or molecular coupling cases.
rate research
Read More
We report on the observation of blue-detuned photoassociation in Rb2, in which vibrational levels are energetically above the corresponding excited atomic asymptote. 85Rb atoms in a MOT were photoassociated at short internuclear distances to levels of the (1)3Pi g state at a rate of approximately 5x10^4 molecules/s. We have observed most of the predicted vibrational levels for all four spin-orbit components 0g+, 0g-, 1g, and 2g, including levels of the 0g+ outer well. These molecules decay to the metastable a3Sigma u+ state, some preferentially to the v=0 level, as we have observed for photoassociation to the v=8 level of the 1g component.
We demonstrate rotational and vibrational cooling of cesium dimers by optical pumping techniques. We use two laser sources exciting all the populated rovibrational states, except a target state that thus behaves like a dark state where molecules pile up thanks to absorption-spontaneous emission cycles. We are able to accumulate photoassociated cold Cs2 molecules in their absolute ground state (v = 0, J = 0) with up to 40% efficiency. Given its simplicity, the method could be extended to other molecules and molecular beams. It also opens up general perspectives in laser cooling the external degrees of freedom of molecules.
The formation of ultracold metastable RbCs molecules is observed in a double species magneto-optical trap through photoassociation below the ^85Rb(5S_1/2)+^133Cs(6P_3/2) dissociation limit followed by spontaneous emission. The molecules are detected by resonance enhanced two-photon ionization. Using accurate quantum chemistry calculations of the potential energy curves and transition dipole moment, we interpret the observed photoassociation process as occurring at short internuclear distance, in contrast with most previous cold atom photoassociation studies. The vibrational levels excited by photoassociation belong to the 5th 0^+ or the 4th 0^- electronic states correlated to the Rb(5P_1/2,3/2)+Cs(6S_1/2) dissociation limit. The computed vibrational distribution of the produced molecules shows that they are stabilized in deeply bound vibrational states of the lowest triplet state. We also predict that a noticeable fraction of molecules is produced in the lowest level of the electronic ground state.
We predict that ultralong-range Rydberg bi-molecules form in collisions between polar molecules in cold and ultracold settings. The collision of $Lambda$-doublet nitric oxide (NO) with long-lived Rydberg NO($nf$, $ng$) molecules forms ultralong-range Rydberg bi-molecules with GHz energies and kilo-Debye permanent electric dipole moments. The Hamiltonian includes both the anisotropic charge-molecular dipole interaction and the electron-NO scattering. The rotational constant for the Rydberg bi-molecules is in the MHz range, allowing for microwave spectroscopy of rotational transitions in Rydberg bi-molecules. Considerable orientation of NO dipole can be achieved. The Rydberg molecules described here hold promise for studies of a special class of long-range bi-molecular interactions.
We report the creation of heteronuclear ultralong-range Rydberg-molecule dimers by excitation of minority $^{88}text{Sr}$ atoms to $5sns,^3S_1$ Rydberg states ($n=31-39$) in a dense background of $^{84}text{Sr}$. We observe an isotope shift of the $ u=0$ vibrational state over this range of $n$ and compare our measurements with a theoretical prediction and a simple scaling argument. With the appropriate choice of principal quantum number the isotope shift is sufficiently large to produce heteronuclear dimers with almost perfect fidelity. When the spectral selectivity is limited, we obtain a lower bound on the ratio of heteronuclear to homonuclear excitation probability of 30 to 1 by measuring the scaling of the molecular excitation rate with varying relative densities of $^{88}text{Sr}$ and $^{84}text{Sr}$ in the ultracold mixture.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
