The low-lying electronic states and optical schemes for the laser cooling of the BH+ and BH- ions

The study of laser cooling of TeH- anion in theoretical approach

The probabilities of laser cooling of TeH^- anion via a spin-forbidden transition and a three-electronic-level transition are proposed. The potential energy curves of the X¹Σ⁺, a³∏, A¹∏, and b³Σ⁺ electronic states of tellurium monohydride anion (TeH^-) are calculated using multi-reference configuration interaction method. Davidson corrections, core-valence correlations and spin-orbit coupling effects are also considered. The AWCV5Z-PP pseudopotential basis set of Te atom is used. Spectroscopic parameters of the Λ-S and Ω states are obtained by solving radial Schrodinger equation. These results are reported at the first time. Permanent dipole moments of the Ω states and transition dipole moments of the a₂1↔X0⁺ and A1↔X0⁺ transitions are also calculated. Highly diagonally distributed Franck-Condon factors of the a₂1↔X0⁺ and A1↔X0⁺ transitions are obtained, the value of f₀₀ is 0.9970 and 0.9980, respectively. Spontaneous radiative lifetimes of the a₂1 and A1 excited states are predicted. i.e. τ(a₂1) = 200.3 ns and τ(A1) = 84.3 ns. Only the main pump laser is required to driving a₂1↔X0⁺ and A1↔X0⁺ transitions. The laser wavelengths both are in the visible region. Doppler temperatures and recoil temperatures of laser cooling TeH^- anion are also predicted.

In search of molecular ions for optical cycling: a difficult road

Optical cycling, a continuous photon scattering off atoms or molecules, is the key tool in quantum information science.

The ground and low-lying excited states and feasibility of laser cooling for GaH+ and InH+ cations

The potential energy curves and transition dipole moments of 1²Σ⁺ and 1²Π states of GaH⁺ and InH⁺ cations are performed by employing ab initio calculations. Based on the potential energy curves, the rotational and vibrational energy levels of the two states are obtained by solving the Schrödinger equation of nuclear movement. The spectroscopic parameters are deduced with the obtained rovibrational energy levels. The spin-orbit coupling effect of the ²Π states for both the GaH⁺ and InH⁺ cations are also calculated. The feasibility of laser cooling of GaH⁺ and InH⁺ cations are examined by using the results of the electronic and spectroscopic properties. The highly diagonal Franck-Condon factors and appropriate radiative lifetimes are determined by using the potential energy curves and transition dipole moments for the ²Π_{1/2, 3/2}↔1²Σ⁺ transitions. The results indicate that the ²Π_{1/2, 3/2}↔1²Σ⁺ transitions of both GaH⁺ and InH⁺ cations are appropriate for the close cycle transition of laser cooling. The optical scheme of the laser cooling is constructed for the GaH⁺ and InH⁺ cations.

Laser cooling of the OH− molecular anion in a theoretical investigation

The schemes for laser cooling of the OH⁻ anion are proposed using an ab initio method.