High-efficiency deterministic Josephson vortex ratchet.
We investigate experimentally a Josephson vortex ratchet--a fluxon in an asymmetric periodic potential driven by a deterministic force with zero time average. The highly asymmetric periodic potential is created in an underdamped annular long Josephson junction by means of a current injector providing an efficiency of the device up to 91%. We measured the ratchet effect for driving forces with different spectral content. For monochromatic high-frequency drive the rectified voltage becomes quantized. At high driving frequencies we also observe chaos, subharmonic dynamics, and voltage reversal due to the inertial mass of a fluxon.
Beck
M
M
Physikalisches Institut-Experimentalphysik II, Universität Tübingen, Auf der Morgenstelle 14, D-72076 Tübingen, Germany.
Goldobin
E
E
Neuhaus
M
M
Siegel
M
M
Kleiner
R
R
Koelle
D
D