around the world scientists are racing
to pursue many different approaches to
developing quantum bits when quantum
bits can be maintained in an optimal
state they can theoretically exploit the
peculiarities of quantum mechanics like
superposition entanglement and
interference to solve particular
problems with many variables and
possible solutions in a fraction of the
time it would take classical computers
but no quantum computer yet exists on a
scale that can deliver on the promise of
solving complicated real-world problems
yet as an industry it is still in the
early days of discovering what's
possible
today scientists often find themselves
limited by the inadequate scale of these
quantum bits systems none of them so far
have been able to scale to enough
quantum bits to fully realize the
promise of quantum computing
the microsoft azure quantum research
team is taking a more challenging but
ultimately more promising approach to
scale quantum computing with the
topological quantum bit to resolve such
a problem
what's a topological quantum bit the
information of the topological quantum
bit is encoded with a pair of majorana
zero modes that are physically separated
the only way to unlock the quantum
information is to look at the combined
state of both myron zero modes
simultaneously
topological quantum bits rely upon
topologically ordered states of matter
to carry out the quantum computation
topological order is in the zero
temperature phase of matter also known
as quantum matter
majorana zero modes are a different kind
of electron quasi particle they are
predicted to appear in a material with
an energy gap when electrons pair up in
another way
the electrons at each end of the chain
have only half the partners they become
two halves of a single quasi particle
widely separated in space this quasi
particle can be thought of as existing
right in the middle of the energy gap at
precisely zero energy called the zero
votes
the crucial point about zero mode quasi
particles is that each one comprises the
electron states at both ends so you
can't find out anything about it or
disturb it by probing just one end if
the two end states could somehow be
brought together in space they would
fuse to produce either an electron or
nothing a vacuum state while separated
they are in a kind of quantum
superposition of both states so a
majorana zero mode can act as a
two-state bit for encoding quantum
information a quantum bit white
topological quantum bit quantum states
are by their nature extremely fragile
and prone to disruption making it
challenging to maintain a stage where
quantum bits can perform computations
reliably to offer advantages over
classical computing quantum bits also
need to process information quickly and
a quantum machine's components can't be
so large that they would fill a
warehouse or a football field which will
make systems built on certain types of
quantum bits difficult to scale
one challenge in developing a quantum
computer is that quantum bits readily
collapse and decode here when they
encounter environmental noise such as
heat stray sub-atomic particles or
magnetic fields
information is lost and the quantum bits
are no longer helpful for computation
errors start to occur and the quantum
computer has to devote even more
unreliable quantum bits to correcting
them it's like trying to keep an entire
room of plates spinning on chopsticks
when the slightest perturbation can
cause one plate to become unbalanced and
start crashing into all the others
topological quantum bits are theorized
to be inherently more stable than other
standard quantum bits produced with
existing methods without sacrificing
size or speed
topological quantum computation is a
route to hardware level fault tolerance
potentially enabling a quantum computing
system with high fidelity quantum bits
fast gate operations and single module
architecture
the quantum information encoded in pair
of majorana zero modes that are
physically separated enables quantum
operations and creates inherent
protection for the quantum bit this
makes a topological quantum bit more
immune to environmental noise which can
interact with or destroy the information
when it encounters just one
what's the scientific breakthrough of
microsoft research to build a
commercially valuable quantum computer
its quantum bits need to perform well
across three key dimensions reliability
speed and size
topological quantum computation can
create quantum properties which
scientists have imagined for nearly a
century but have not been able to
unambiguously produce in the real world
so far
scientists have sought to create and
observe these excitations since they
were first theorized about in 1937
these quantum excitations don't usually
exist in nature nobody has really seen
these majorana zero modes in real life
and must be coaxed into appearing under
incredibly precise conditions
the microsoft researchers have
engineered devices that allow them to
induce a topological phase of matter
book ended by a pair of myrana zero
modes they have also been able to
produce what is known as a topological
phase and measure the topological gap
which quantifies the stability of the
phase
topological quantum computation is a
route to hardware level false tolerance
potentially enabling a quantum computing
system with high fidelity quantum bits
fast gate operations and single module
architecture
now microsoft researchers can create and
sustain a quantum phase with meyer on
zero modes and a measurable topological
gap this removes the biggest obstacle to
producing a unique type of quantum bit
to a path towards a fully scalable
quantum computing machine in the future
which will in turn enable us to realize
the full promise of quantum to solve the
most complex and pressing challenges our
society faces
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