Sr polarizabilities, magic wavelengths, and their applications

Atomic strontium is used as the atom of choice for many ultracold atom experiments and quantum

technologies, including atomic clocks, atomtronic circuits, quantum simulation and computation,

and others. These applications use trapped ultracold atoms to precisely localize and control

them with minimum decoherence. Laser cooling, trapping, and control of atoms in optical potentials

requires knowledge of the polarizability of trapped atoms at a certain laser frequency. Magic

wavelength values where the polarizabilities of two states match and tune-out wavelengths where

the polarizability turns to zero are also needed for many applications. The main problem of accurately

computing the dynamic polarizabilities of multivalent atoms is a significant time that was

required to compute a data point at a specific wavelength, making the determination of magic and

tune-out wavelengths that require many data points for a range of wavelengths a difficult task. We

have developed a parallel automated polarizability code that allows us to efficiently compute polarizabilities

for a wide range of wavelength using a hybrid approach that combines a configuration

interaction and coupled-cluster methods. We tested this approach on the calculations of dynamic

polarizabilities for the 5s2 1S0, 5s5p 3P1,2,3, 5s5p 1P1 and 5s4d 1D2 states of Sr for a broad range of

wavelengths up to 2000 nm. The calculations include vector polarizabilities allowing one to compute

data for any laser polarization. We also present magic wavelengths and tune-out wavelengths and

several applications of our calculations. This approach can be used for a variety of systems beyond

Sr. All polarizability data will be made available at the Portal for High-Precision Atomic Data and

Computation [1].

[1] Parinaz Barakhshan, Adam Marrs, Akshay Bhosale, Bindiya Arora, Rudolf Eigenmann, Marianna

S. Safronova, Portal for High-Precision Atomic Data and Computation (version 2.0). University

of Delaware, Newark, DE, USA. URL: https://www.udel.edu/atom [April 2022].