Feasibility of a novel hexagonal binary decision diagram (BDD) quantum circuit approach based on Schottky wrap gate (WPG) control of GaAs/AlGaAs hexagonal nanowire network has been demonstrated through fabrication of half adders and full adders. Quantum BDD node devices were designed and realized utilizing WPG-controlled quantum wire (QWR) and single electron switches. BDD half sum and carry elements of a half adder were fabricated by integrating the WPG BDD node devices and they operated correctly through either quantum transport at low temperature or many electron classical transport at room temperature. Successful design of hexagonal BDD full adders for arbitrary bits on a hexagonal network without nanowire crossover and fabrication of QWR-based BDD 2-bit full adder on the AlGaAs/GaAs etched hexagonal nanowire network with node density of 10(7) cm(-2) clearly indicated the capability of the present approach for large scale quantum device integration. (C) 2002 Elsevier Science Ltd. All rights reserved.