68
PHYSICS OF THE IMPOSSIBLE
one hundred digits, then it might take a digital computer more than a
hundred years to find these two factors from scratch. Such a code is essentially unbreakable today.
But in 1994 Peter Shor of Bell Labs showed that factoring large
numbers could be child's play for a quantum computer. This discovery
immediately piqued the interest of the intelligence community. In
principle a quantum computer could break all the world's codes,
throwing the security of today's computer systems into total disorder.
The first country that is able to build such a system would be able to
unlock the deepest secrets of other nations and organizations.
Some scientists have speculated that in the future the world's economy might depend on quantum computers. Silicon-based digital computers are expected to reach their physical limits in terms of increased
computer power sometime after 2020. A new, more powerful family of
computers might be necessary if technology is going to continue to advance. Others are exploring the possibility of reproducing the power of
the human brain via quantum computers.
The stakes, therefore, are very high. If we can solve the problem of
coherence, not only might we be able to solve the challenge of teleportation; we might also have the ability to advance technology of all
kinds in untold ways via quantum computers. This breakthrough is so
important that I will return to this discussion in later chapters.
As I pointed out earlier, coherence is extraordinarily difficult to
maintain in the lab. The tiniest vibration could upset the coherence of
two atoms and destroy the computation. Today it is very difficult to
maintain coherence in more than just a handful of atoms. Atoms that
are originally in phase begin to decohere within a matter of nanoseconds to, at best, a second. Teleportation must be done very rapidly, before the atoms begin to decohere, thus placing another restriction on
quantum computation and teleportation.
In spite of these challenges, David Deutsch of Oxford University
believes that these problems can be overcome: "With luck, and with
the help of recent theoretical advances, [a quantum computer] may
take a lot less than 50 years
It would be an entirely new way of harnessing nature."
PHYSICS OF THE IMPOSSIBLE
one hundred digits, then it might take a digital computer more than a
hundred years to find these two factors from scratch. Such a code is essentially unbreakable today.
But in 1994 Peter Shor of Bell Labs showed that factoring large
numbers could be child's play for a quantum computer. This discovery
immediately piqued the interest of the intelligence community. In
principle a quantum computer could break all the world's codes,
throwing the security of today's computer systems into total disorder.
The first country that is able to build such a system would be able to
unlock the deepest secrets of other nations and organizations.
Some scientists have speculated that in the future the world's economy might depend on quantum computers. Silicon-based digital computers are expected to reach their physical limits in terms of increased
computer power sometime after 2020. A new, more powerful family of
computers might be necessary if technology is going to continue to advance. Others are exploring the possibility of reproducing the power of
the human brain via quantum computers.
The stakes, therefore, are very high. If we can solve the problem of
coherence, not only might we be able to solve the challenge of teleportation; we might also have the ability to advance technology of all
kinds in untold ways via quantum computers. This breakthrough is so
important that I will return to this discussion in later chapters.
As I pointed out earlier, coherence is extraordinarily difficult to
maintain in the lab. The tiniest vibration could upset the coherence of
two atoms and destroy the computation. Today it is very difficult to
maintain coherence in more than just a handful of atoms. Atoms that
are originally in phase begin to decohere within a matter of nanoseconds to, at best, a second. Teleportation must be done very rapidly, before the atoms begin to decohere, thus placing another restriction on
quantum computation and teleportation.
In spite of these challenges, David Deutsch of Oxford University
believes that these problems can be overcome: "With luck, and with
the help of recent theoretical advances, [a quantum computer] may
take a lot less than 50 years
It would be an entirely new way of harnessing nature."