Persistent currents in helical structures

[摘要] The recent discovery of mesoscopic electronic structures, in particular the carbon nanotubes, made necessary an investigation of what effect a helical symmetry of the conductor (metal or semiconductor) may have on the persistent current oscillations. We investigate persistent currents in helical structures which are nondecaying in time, not requiring a voltage bias, dissipationless stationary flow of electrons in a normal-metallic or semiconducting cylinder or circular wire of mesoscopic dimension. In the presence of magnetic flux along the toroidal structure, helical symmetry couples circular and longitudinal currents to each other. Our calculations suggest that circular persistent currents in these structures have two components with periods Phi(0) and Phi(0)/s (s is an integer specific to any geometry). However, resultant circular persistent current oscillations have Phi(0) period.

[发布日期] 2004-11-01

[关键词] CARBON NANOTUBES;RINGS;SINGLE;LOOP