AHARONOV-BOHM EFFECT IN A QUANTUM RING WITH STRONG ELECTRON-ELECTRON CORRELATIONS

We calculate the magnetic moment (''persistent current'') in a strongl y correlated electron system - a Wigner crystal - in a one-dimensional ballistic ring (quantum ring). The flux- and temperature dependence o f the persistent current is shown to be essentially the same as for a system of noninteracting electrons. In contrast, by incorporating into the ring geometry a tunnel barrier, that pins the Wigner crystal, the current is suppressed and its temperature dependence is drastically c hanged. The competition between two temperature effects - a reduced ba rrier height for macroscopic tunneling and a loss of quantum coherence - results in a sharp peak in the temperature dependence, which for a rigid Wigner crystal appears at T similar to 0.5 $($) over bar$$ hs/L, (s is the sound velocity of the Wigner crystal, L is the length of th e ring).