Aharonov-Bohm effect and plasma oscillations in superconducting tubes and rings

Low-frequency plasma oscillations in superconducting tubes are considered. The emergence of two different dimensionality regimes of plasma oscillations in tubes exhibiting a crossover from one-dimensional to two-dimensional behavior, depending on whether kR < 1 or kR > 1, where k is the plasmon wave vector and R is the radius of the tube, is discussed. The Aharonov-Bohm effect pertaining to plasma oscillations in superconducting tubes and rings, resulting in an oscillatory behavior of the plasmon frequency as a function of the magnetic flux, with a flux quantum period hc/2e (analog of the Little-Parks effect) is studied. The amplitude of the oscillations is proportional to (xi/R)(2), where xi is the superconducting coherence length.