Transcript 9-30 powerpoint

Recent Quantum Computing
and
Bulk Spin Resonance Quantum
Computing
Problems with current computing:
• As computers get faster and smaller, limits
will be reached that cannot be broken.
• If computers are to continue improving, a
new method of computing must be
created.
• Quantum Computing
Problems with Quantum
Computing:
• Qubit
• The qubits need to be protected from the
environment. This way they stay in the
quantum phase.
• The qubits need to be coupled to the
environment. It won’t be any good to have
a qubit and not be able to read it.
• These facts contradict each other.
What do we do about it?
• We know it is hard to make a quantum
computer stay a quantum computer.
• Two scientists, Neil Gershenfeld and Isaac
Chuang have developed a new method for
quantum computing that may bypass the
original constraints.
New method:
• Don’t try to isolate separate qubits, but use
a large thermal ensemble.
• Apply RF pulses to the system,
resonances occur and it creates a
deviation from equilibrium that simulates
the behavior of qubits.
New method:
• The spin of the particles is isolated from
the environment, and can therefore last
much longer than previous computers.
• This means that more computations can
be done before the coherence is lost.
Also
• Because the qubits are together in a
group, the quantum state can be read.
• This couldn’t be done by attempting to
read the state of an individual qubit.
Also
• The most important part of the computer
uses ordinary molecules. It is nothing
new.
• A source of resonance is needed, such as
a Nuclear Magnetic Resonance
spectrometer.
• This will allow for around 10 qubits.
If…
• If this new method works,
• The new computer could demonstrate
extremely fast algorithms and quantum
error correction.
• New quantum states could be realized that
violate Bell’s Theorem.
• The computer could eventually be the size
of a current desktop.