Switching in a reversible spin logic gate

Theoretical results for the adiabatic switching of a reversible quantum inverter-realized with two antiferromagnetically coupled single electrons in adjacent quantum dots-are presented. It is found that a large exchange interaction between the electrons favors faster switching but also makes the timing of the read cycle more critical. Additionally, there exists an optimal input signal energy to achieve complete switching. Only for this optimal signal energy does the inverter yield an unambiguous, logically definite state. An experimental strategy for realizing circuits based on such gates in self-assembled arrays of quantum dots is briefly discussed. (C) 1997 Academic Press Limited.