Proceedings Article | 4 February 2013
KEYWORDS: Superlattices, Stereolithography, Quantum dots, Solids, Physics, Sensors, Terahertz radiation, Gallium arsenide, Nanophotonics, Heterojunctions
Modern Nano electronics involves the use of heterojunctions in forming energy steps
based on band-edge alignments in effecting quantum confinements. When the electron meanfree-
path exceeds couple of periods, man-made quantum states appeared, mimicking natural
solids with sharpness determined by the degree of coherence dictated by a relatively long meanfree-
path. When a single quantum well is involved, the structure is represented by resonant
tunneling. This process can further be extended to 3D (3-dimension), known as QD, for quantum
dot, however, thus far only few systems have been found possible, mostly involving InAs, or
InN. However, the real problem lies in I/O, making contact to a single quantum dot, seems to be
impractical on account of difficulties in making contacts in Nano scale regime. The issue with
impedance matching, is the most important aspect for efficient devices, whether as detectors, or
as generator in frequencies between THz to visible light. As size shrinks to Nano-regime, even
the wavelength of IR is too large for effective coupling to the quantum dots without some sort of
coupling such as the use of Fabry-Perrot mirrors, which is in fact unsuited for quantum dots,
unless these dots are arranged in an array mimicking a solid with translational symmetry, which
in fact defeating the purpose of going to quantum dots, except when the distribution of these
quantum dots are arranged either representable by some distribution functions suitable for
arriving at a meaningful average, or periodically mimicking a solid, such as the man-made
superlattice, SL, originally proposed by Esaki and Tsu. [1, 2]. Interestingly Esaki and Tsu were
asked to remove the reference on doping in the barrier region for increased mobility by the
reviewer for the IBM’s own J. of Research and Development. We did protest to the Editor-in-
Chief of the Journal to no avail! Because of this experience, it did occur to me of requiring
something beyond the regular reviewing process in technical journals. Some ten years ago, I
proposed to M. Henini the need to have a journal with two outlets for publications, one ‘regular’,
and another as ‘special’: rejected by reviewer, but accepted by the editorial staff. For some
reason, we did not get enough support then.
