Conditions for self-assembly of quantum fortresses and analysis of their possible use as quantum cellular automata
- Department of Physics, University of Virginia, Charlottesville, Virginia 22904 (United States)
In this study, we detail the conditions that result in the generation of self-assembled quantum fortresses (QFs), in SiGe/Si. A QF consists of four quantum dots (QDs) clustered around a central square pit, one QD per side. This structure strongly resembles the proposed quantum cellular automata (QCA) unit cell - the basis for a computer architecture. We map the growth conditions (epilayer thickness and Ge concentration) under which self-assembly of strain-stabilized QFs and their precursors occur. Additionally, we characterize how QFs change in height, width, and internal size scales within this parameter space. From this information, we develop a phenomenological model for why QFs form based upon changes in lattice spacing. We then calculate how QFs of the observed shapes and sizes would function as QCAs based on a Hubbard-type Hamiltonian model. This analysis reveals that self-assembled QFs grown at 550 deg. C, a rate of 1 A/s, a SiGe alloy composition of 37-40%, and a thickness of 15-35 nm could be used as QCAs.
- OSTI ID:
- 20668196
- Journal Information:
- Journal of Applied Physics, Vol. 97, Issue 4; Other Information: DOI: 10.1063/1.1844620; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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