Information in a quantum cellular automata architecture is encoded in the polarization state of a cell, i.e. in the occupation numbers of the quantum dots of which the cell is made up. Non-invasive charge detectors of single electrons in a quantum dot are therefore needed, and recent experiments have shown that a quantum constriction electrostatically coupled to the quantum dot may be a viable solution. We have performed a numerical simulation of a system made of a quantum dot and a nearby quantum point contact defined, by means of depleting metal gates, in a two-dimensional electron gas at a GaAs/AlGaAs heterointerface. We have computed the occupancy of each dot and the resistance of the quantum wire as a function of the voltage applied to the plunger gate, and have derived design criteria for achieving optimal sensitivity. (C) 1998 Elsevier Science S.A. All rights reserved.
Simulation of a non-invasive charge detector for quantum cellular automata
IANNACCONE, GIUSEPPE;MACUCCI, MASSIMO;
1998-01-01
Abstract
Information in a quantum cellular automata architecture is encoded in the polarization state of a cell, i.e. in the occupation numbers of the quantum dots of which the cell is made up. Non-invasive charge detectors of single electrons in a quantum dot are therefore needed, and recent experiments have shown that a quantum constriction electrostatically coupled to the quantum dot may be a viable solution. We have performed a numerical simulation of a system made of a quantum dot and a nearby quantum point contact defined, by means of depleting metal gates, in a two-dimensional electron gas at a GaAs/AlGaAs heterointerface. We have computed the occupancy of each dot and the resistance of the quantum wire as a function of the voltage applied to the plunger gate, and have derived design criteria for achieving optimal sensitivity. (C) 1998 Elsevier Science S.A. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
