Spin blockade of quantum cellular automata effects in a few electron triple quantum dot

It has been previously demonstrated, employing charge detection techniques, that quantum cellular automata (QCA) processes exist in the vicinity of quadruple degeneracy points in both ring and serial arrangements of lateral triple quantum dots. The effect is primarily an electrostatic one. In this paper, we report on transport measurements through a triple dot potential and study experimentally the interplay between these QCA phenomena and the Pauli (spin) blockade effect. We demonstrate experimentally that the interaction between these processes leads to a higher order and indirect form of spin blockade in which the QCA effect itself is blockaded. Crown Copyright (C) 2007 Published by Elsevier B.V. All rights reserved.