  Lorentz symmetry violation (LV) was recently proposed to be testable with a
new method, in which the effect of the violation is described as a certain
local interaction [R. Shaniv, et al, PRL 120, 103202 (2018)]. We revisit this
LV effect in the paper and show that it is not only local, but it also
represents a classical violation according to the recent quantum formulation of
the Einstein equivalence principle (EEP). Based on a harmonically trapped
spin-1/2 atomic system, we apply the results of table-top experiments testing
LV effect to estimate the corresponding violation parameter in the quantum
formulation of EEP. We find that the violation parameter is indeed very small,
as expected by the earlier theoretical estimation.
