Emending thermal dispersion interactions of Li, Na, K, and Rb alkali-metal atoms with graphene in the Dirac model

Abstract

Using accurate dynamic polarizabilities of Li, Na, K and, Rb atoms, we scrutinize the thermal Casimir-Polder interactions of these atoms with a single layered graphene. Considering the modified Lifshitz theory for material interactions, we reanalyze the dispersion coefficients ($C_3$s) of the above atoms with graphene as functions of separation distance, gap parameter and temperature among which some of them were earlier studied by estimating dynamic polarizabilities of the above atoms from the single oscillator model approximation. All these $C_3$ coefficients have been evaluated in the framework of the Dirac model. The interactions are described for a wide range of distances and temperatures to demonstrate the changes in behavior with the varying conditions of the system and also sensitivities in the interactions are analyzed by calculating them for different values of the gap parameter. From these analyses, we find a suitable value of the gap parameter for which the true nature of the interactions in graphene can be surmised more accurately.