"We are
studying neutral atom qubits because it is clear that you can have thousands in
an
apparatus,"
said Weiss. "They don't take up much space and they don't interact with each
other
unless we want
them to." Image: © iStock Photo monsitj
(August 12, 2015) For
any computer, being able to manipulate information is essential, but for
quantum computing, singling out one data location without influencing any of
the surrounding locations is difficult. Now, a team of Penn State physicists
has a method for addressing individual neutral atoms without changing
surrounding atoms.
"There are a set of things that we have to have to do
quantum computing," said David S. Weiss, professor of physics. "We
are trying to step down that list and meet the various criteria. Addressability
is one step."
Quantum computers are constructed and operate in completely
different ways from the conventional digital computers used today. While
conventional computers store information in bits, 1's and 0's, quantum
computers store information in qubits. Because of a strange aspect of quantum
mechanics called superposition, a qubit can be in both its 0 and 1 state at the
same time. The methods of encoding information onto neutral atoms, ions or
Josephson junctions -- electronic devices used in precise measurement, to
create quantum computers -- are currently the subject of much research. Along
with superposition, quantum computers will also take advantage of the quantum
mechanical phenomena of entanglement, which can create a mutually dependent
group of qubits that must be considered as a whole rather than individually.
"Quantum computers can solve some problems that
classical computers can't," said Weiss. "But they are unlikely to
replace your laptop."
According to the researchers, one area where quantum
computers will be valuable is in factoring very large numbers created by
multiplying prime numbers, an approach used in creating difficult-to-break
security codes.
Weiss and his graduate students Yang Wang and Aishwarya
Kumar, looked at using neutral atoms for quantum computing and investigated
ways to individually locate and address an atom to store and retrieve
information. They reported their results in a recent issue of Physical Review
Letters.