Computing Periodic Symmetric Functions in Single Electron
Tunneling Technology
C.H. Meenderinck, S.D. Cotofana
Computer Engineering Lab, Delft University of Technology, Delft, The Netherlands
{Cor, Sorin}@CE.ET.TUDelft.NL
Abstract
This paper investigates the implementation of Periodic
Symmetric Functions (PSF) in single electron tunneling
technology. First, a building block is proposed that
performs a multiple input PSF. The block we propose
can be used for the computation of any function that
is or can be expressed as a PSF, thus it can be utilized
for the implementation of a large number of arithmetic
operations, e.g., parity, addition, multi-operand addi-
tion, as they belong to the class of generalized PSFs.
Subsequently, a PSF based addition scheme is proposed
and it is demonstrated how this adder can be used in
a Single Electron Encoded Logic (SEEL) environment.
Finally, a 3-bit instance of the addition scheme is
presented and verified by means of simulation.
Keywords: single electron tunneling, periodic symme-
tric function.
1. INTRODUCTION
It is generally expected that current semiconductor
technologies, i.e., CMOS, cannot be pushed beyond a
certain limit because of problems arising in the area
of power consumption and scalability. A promising
alternative is Single Electron Tunneling (SET) technol-
ogy [1], which has the potential of performing compu-
tation with lower power consumption than CMOS and
it is scalable to the nanometer region and beyond [2].
Several proposals have been made to implement
computational operations using SET technology and
these implementations are mainly categorized in two
types (see for example [1], [3]). The first type of imple-
mentation represents logic values by voltage (see [3] for
an overview) while the second type of implementation
represents bits by single electrons. Single Electron
Encoded Logic (SEEL) [4] is an examples of the latter.
Thus far most implementations focussed on design-
ing logic gates to perform operations in the digital
domain. SET technology however,