Computer Shopper - UK (2019-08)

ISSUE 378|COMPUTERSHOPPER|AUGUST 2019 117117

at this by referring to atransistor that

can normally be on or off,representing

0or1inacomputer’s binary language,

and suggested that, once we get to

sub-atomic particles, all this changes

due to the possibility of superposition.

Certainly we could use asingle

electron as acomputing bit, using the

spin-up and spin-down states to

represent 0or1,but it doesn’t end

there.Ifthat electron was put intoa

stateofsuperposition, it could

represent both 0and 1atthe same

time.What’s more,ifanoperation was

carried out on that bit, the operation

would work on its two values

simultaneously.And it gets better as

you add more bits, or qubits as we

should call them, this being shorthand

forquantum bit. If we have two qubits,

theycould hold the four values of 00,

01, 10 and 11 simultaneously,and

moving forward, the number of

superposed states doubles with every

additional qubit. So an 8-qubit

computer could operateon256 bits

values simultaneously and, by the time

we get to the equivalent of today’s

64-bit architecture,which would be

64 qubits in the quantum world, avast

18,446,744,073,709,551,616 operations

could take place at the same time.How

about that forparallelism?

With conventional computers, to

double the performance you need

twice as much hardware; with a

quantum computer you only need to

add asingle qubit. Unimaginable

power is just aqubit away. If only

things were that simple.

THESTATEOFPLAY

Areview of companies researching

quantum computing reveals big players

including Google,plus several other

companies who,asyet, are largely

unknown to the layperson. It’s

interesting to note, however,that

Microsoft, Intel and IBM –the three

companies who,arguably,were the

most influential in the birth of the

personal computing revolution –all

have active quantum computing

research projects. This begs the

question of whether history is about

to repeat itself,sowewere eager to

learn about their work in the quantum

realm and their predictions forthe

future.Wespoke to Intel and IBM to

find out about their progress to date,

the challenges and their future plans

forthis embryonic technology.

Aquick surveyofmilestones in

quantum computing research reveals

one keymetric: the number of qubits

that have been implemented in asingle

device.And progress seems to have

been slow,much slower than the

increase in the number of bits in the

early days of the microprocessor.

The first demonstration of a

quantum computation, in 1998, had

just two qubits, and it took 19 years for

this to equal the 16 bits of the Intel

8088 processor that was used in the

first IBM PC. So is the quest forqubits

the main difficulty in bringing us a

workable quantum computer and, if so,

why is progress so slow?

Dr Stefan Filipp,quantum research

technical lead at IBM Research in Zurich,

explains: “Actually,the number of qubits

is only part of the story.Ifwewant to

use quantum computers to solve real

problems, the number of qubits is

important, but so is the error rate.

In practical devices, the effective error

ratedepends on the accuracy of each

operation as well as how the processor

performs the operations, and also on

how many operations it takes to solve

aparticular problem.”

While again not dismissing the need

forqubits, Jim Clark, Intel’s director of

quantum hardware,also referred to the

UNIMAGINABLE

POWER IS JUST

AQUBITAWAY.

IF ONLYTHINGS

WERE THAT

SIMPLE.

TOP:Gold-coloured

coaxial cables are

used to send inputs

and outputs from

inside the dilution

refrigerator,which is

neededtokeepIBM’s

quantum chip colder

than outer space

ABOVE:Microwave

apparatus used in a

quantum computing

experiment at the

National Institute

of Standards and

Technology

Im
ag
e:

IBM

Re

sea

rch