Controlling the charging energy of arrays of tunnel junctions

✍ Scribed by C Kurdak; A.J Rimberg; T.R Ho; John Clarke; J.D Walker

• Publisher: Elsevier Science
• Year: 2000
• Tongue: English
• Weight: 126 KB
• Volume: 5
• Category: Article
• ISSN: 1386-9477
• DOI: 10.1016/s1386-9477(99)00258-1

✦ Synopsis

We describe a new technique to control in situ charging energy of systems of coupled metallic or superconducting islands. To illustrate the technique, we have fabricated two-dimensional arrays of Al islands on GaAs=AlAs heterostructures. Each island is coupled to its nearest-neighbor by a submicron Al=AlO x =Al tunnel junction and to the three-dimensional electron gas (3DEG) located below the surface of the heterostructure by a capacitance Cg. We vary Cg, which dominates the charging energy of the array, by depleting the electrons in the 3DEG by means of a negative voltage applied to the array. With the array driven normal by a magnetic ÿeld, a decrease in C g increases in both the o set voltage and the period of the Coulomb blockade oscillations.