CS 295-6 - Introduction to Nanocomputing
Readings for Lecture 09
These readings are restricted to Brown University.
Quantum Computation
-
Quantum-dot cellular automata: Review and recent experiments (invited) by
G. L. Snider, A. O. Orlov, I. Amlani, X. Zuo, G. H. Bernstein, C. S. Lent, J. L. Merz,
and W. Porod,
J. Applied Physics, Vol. 85, No. 2, pp. 4283-4285 (1999)
Abstract: An introduction to the operation of quantum-dot cellular automata is presented, along with recent
experimental results. Quantum-dot cellular automata (QCA) is a transistorless computation
paradigm that addresses the issues of device density and interconnection. The basic building blocks
of the QCA architecture, such as AND, OR, and NOT are presented. The experimental device is a
four-dot QCA cell with two electrometers. The dots are metal islands, which are coupled by
capacitors and tunnel junctions. An improved design of the cell is presented in which all four dots
of the cell are coupled by tunnel junctions. The operation of this basic cell is confirmed by the
externally controlled polarization change of the cell.
-
Digital Logic Gate Using
Quantum-Dot Cellular
Automata
by
Islamshah Amlani, Alexei O. Orlov,
Geza Toth, Gary H. Bernstein, Craig S. Lent,
Gregory L. Snider,
Science, Vol. 284, pp. 289-291 (1999).
Abstract: A functioning logic gate based on quantum-dot cellular automata is presented,
where digital data are encoded in the positions of only two electrons. The logic
gate consists of a cell, composed of four dots connected in a ring by tunnel
junctions, and two single-dot electrometers. The device is operated by applying
inputs to the gates of the cell. The logic AND and OR operations are veriŢed
using the electrometer outputs. Theoretical simulations of the logic gate output
characteristics are in excellent agreement with experiment.
-
A Potentially Implementable FPGA for Quantum Dot Cellular Automata
by
Michael T. Niemier, Arun F. Rodrigues, and Peter M. Kogge,
1st Workshop on Non-Silicon Computation (NSC-1), (2002)
Abstract: While still relatively “new”, the quantum-dot cellular
automata (QCA) appears to be able to provide many of the
properties and functionalities that have made CMOS successful
over the past several decades. Early experiments
have demonstrated and realized most, if not all, of the “fundamentals”
needed for a computational circuit – devices,
logic gates, wires, etc. This study introduces the beginning
of a next step in experimental work: designing a computationally
useful – yet simple and fabricatable circuit for
QCA. The design target is a QCA Field Programmable Gate
Array.
-
Modeling and Prospects for a Solid-State
Quantum Computer
by
H. E. Ruda and Bi Qiao,
Proceedings of the IEEE, Vol. 91, No. 11, pp. 1874-1883 (2003).
Abstract: Traditional approaches to computing based on nanoelectronics
will likely need to embrace quantum phenomena over the coming
decade with the trend toward decreasing on-chip feature sizes. Concurrently,
as resonant tunneling and single-electron-based quantum
devices become more prevalent, one can expect quantum computing
and quantum information based on appropriate isolated and coupled
low-dimensional semiconducting systems to attract more attention.
We report on work aimed at understanding the limitations
on how to implement practical quantum information systems that
counter the natural effects of decoherence and offer suitable approaches
to control of such systems. The emphasis in this paper is
on open systems.We close the paper with some remarks on possible
practical schemes for fabricating such systems and identify some of
the challenges that lie ahead in realizing these schemes.
-
Using Circuits and Systems-Level Research to Drive Nanotechnology
by
Michael T. Niemier, Ramprasad Ravichandran, and Peter M. Kogge
ICCD (2004).
Abstract: This paper details nano-scale devices being researched
by physical scientists to build computational systems. It
also reviews some existing system design work that uses
the devices to be discussed. It concludes with a
discussion of how the authors believe system-level
research can best be used to positively affect actual
device development. This work has led to a more
thorough design methodology that will address whether
or not computationally interesting and buildable circuits
are possible with the Quantum-dot Cellular Automata
(QCA), while also providing significant wins over end-ofthe-
roadmap CMOS.