104 MARCH2020|COMPUTERSHOPPER|ISSUE385
Newmaterials
There’s been alot oftalk in recent
years of Moore’s Law coming to an
end and, with it, an end to the
continual year-on-year performance
gains we’ve known forhalf acentury.
All isn’t lost, however.Eventually,some
of the novel paradigms we investigate
here might well go some wayto
providing future speed improvements.
In the shorter term, however,
scientists are considering whether
gains can be achieved by themore
conservative approach of keeping with
the same basic principles, but replacing
silicon. Make no mistake,though:
even that will require substantial
innovation in materials science and
semiconductor engineering.
Silicon, of course,isasemi-metallic
element that can be made intothe
semiconductors needed to fabricate
transistors by aprocess called doping,
which involves adding small quantities
of other elements. It’s not the only
element that can form the building
blocks of electronics, however; in fact,
germanium, one of silicon’s close
neighbours in the periodic table,was
used in some of the first transistors.
While there are several other
elements that could, in theory,also be
used as semiconductors, much of
today’s research is involved with alloys
such as InGaAs –that’s amixture of
indium, gallium and arsenic –which
hold the promise of faster and more
energy-efficient transistors, which will
lead to faster,lesspower-hungry chips.
Perhaps the greatest potential for
the future of electronics, while also
posing one of the greatest challenges,
is the application of some of the
up-and-coming new forms of carbon
such as graphene and carbon
nanotubes. And here,would you
believe,the prospectofclock speeds
as high as 1THz –that’s1,000GHz –
has been bandied around.
Analogue computing
The idea of afuture foranalogue
computing –and specifically electronic
analogue computing –might seem
surprising since it represents the past,
being apredecessor to the digital
computer,but it might indeed playa
part in the future.
Analogue computers aren’t
universal, like today’s digital computers,
since they’re specifically intended for
solving differential equations. Hence
theywere used even in the early days
ofdigital computing for scientific
computing applications, including
simulation. Theywere so much faster
than digital computers, and could still
be today, but theyhad some serious
drawbacks that saw them sidelined as
digital computers improved. One
drawback was their limited accuracy,
but perhaps the greatest disadvantage
was that programming them was avery
laborious process that involved making
physical connections between the
various computing elements.
Today, the second of these
drawbacks can be largely circumvented,
and this has resulted in aresurgence of
interest in the technique.Given aset of
ABOVE:Some
ofthe newer
allotropes of
carbon, such as
carbon nanotubes,
offerthe promise
ofhigh-speed
transistors when
silicon eventually
runs out ofsteam
RIGHT:Analogue
electronics is one
of several outdated
technologies which
many experts
believe deserves a
new lease of life
