A device is proposed that is similar in spirit to the electron turnstile
except that it operates within a quantum Hall fluid. In the integer quantum
Hall regime, this device pumps an integer number of electrons per cycle. In the
fractional regime, it pumps an integer number of fractionally charged
quasiparticles per cycle. It is proposed that such a device can make an
accurate measurement of the charge of the quantum Hall effect quasiparticles.Comment: 4 pages, LaTeX, 4 figures include
