Stability of particle rotation in a rotating electric field.

Depending on the parameters of a particle and of a host medium, a particle in a rotating electric field can rotate either in the direction of rotation of electric field or in the opposite direction. There exists a range of parameters where both regimes of rotation can be realized simultaneously. In this study we investigate stability of rotation regimes in the whole range of parameters. We determine the range of parameters where different modes of particle rotation are stable, the range of parameters where only one regime of rotation is stable and the range of parameters where both regimes of rotation are unstable. It is shown that if the mode of rotation is realized outside the domain of the existence of two regimes of rotation, then this rotation mode is stable. Consequently, unstable regimes can be realized only in the range of parameters where both modes of rotation can exist simultaneously. We suggest a simple algorithm for determining the range of stability through the parameters of the system which does not require calculating frequencies of particle rotation in each of the possible rotation regimes.