HOT-ELECTRON EFFECTS IN METALLIC SINGLE-ELECTRON COMPONENTS

Thermalisation of single electron devices is of considerable current i nterest because of its fundamental and practical consequences. We pres ent experimental evidence of the effect of electrode volume and its sh ape on thermal equilibration of small metallic islands for single elec tron tunnelling. Heat transport between the conduction electrons and t he lattice in a metal is commonly accepted to obey the proportional to T-e(5)-T-0(5) law at low electron and lattice temperatures, T-e and T -0, respectively. We have investigated the power law and found that it obeys the proportional to T-5 law only for the smallest islands, and in the majority of the cases considered, it rather follows a law propo rtional to T-p where p <5. The thermal coupling can be improved by inc reasing the volume of the island, but, upon increasing the surface are a alone, the effective coupling constant is reduced indicating the pre sence of local hot electrons.