1. A picoelectronic device comprising: first and second conductor chains, each comprising multiple monomor units having mutually conjugated bonding; a first barrier region, connected to said first conductor chain, said first barrier having a potential energy for electrons which is less favorable than that of said first conductor chain; a second barrier region, connected to said second conductor chain, said second barrier having a potential energy for electrons which is less favorable than that of said second conductor chain; a well region, connected to said first and second barrier regions, said well region having a potential energy for electrons which is more favorable than that of said first and second barrier regions; a third barrier region, connected to said well region, said third barrier having a potential energy for electrons which is less favorable than that of said well; a third conductor chain, comprising multiple monomor units having mutually conjugated bonding, and operatively connected to said well region through said third barrier region; whereby changing potentials applied to said third chain can effect modulation of currents between said first and second chains.