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Exact modeling of finite temperature and quantum delocalization effects on reliability of quantum-dot cellular automata

Research output: Contribution to journalArticleScientificpeer-review


Original languageEnglish
Article number065103
JournalJournal of Physics D: Applied Physics
Issue number6
Publication statusPublished - 11 Jan 2016
Publication typeA1 Journal article-refereed


A thorough simulation study is carried out on thermal and quantum delocalization effects on the feasibility of a quantum-dot cellular automata (QCA) cell. The occupation correlation of two electrons is modeled with a simple four-site array of harmonic quantum dots (QD). QD sizes range from 20 nm to 40 nm with site separations from 20 nm to 100 nm, relevant for state-of-the-art GaAs/InAs semiconductor technology. The choice of parameters introduces QD overlap, which is only simulated properly with exact treatment of strong Coulombic correlation and thermal equilibrium quantum statistics. These are taken into account with path integral Monte Carlo approach. Thus, we demonstrate novel joint effects of quantum delocalization and decoherence in QCA, but also highly sophisticated quantitative evidence supporting the traditional relations in pragmatic QCA design. Moreover, we show the effects of dimensionality and spin state, and point out the parameter space conditions, where the 'classical' treatment becomes invalid.


  • path integral Monte Carlo, quantum dot cellular automata, semiconductor quantum dots

Publication forum classification

Field of science, Statistics Finland