A team of researchers at Hitachi-Cambridge has developed a
silicon device to facilitate quantum computing.
The
device, known as a quantum-dot charge qubit is based on years of
work on single electronics. Hitachi said the breakthrough
represents the first step in the development of a quantum computer
based on conventional silicon technology.
Unlike the binary (ones and zeros) system used in modern computers,
quantum computers make use of quantum bits (qubits), which Hitachi
said can exist in both states - zero and one - simultaneously.
Qubits are also subject to quantum entanglement. When two or more
are entangled, they behave as one system, so that the state of one
qubit depends directly on the state of the others. Thus the
potential processing power of a quantum information system
increases exponentially rather than linearly with the number of
qubits.
Although the principles behind quantum computing have been
established and small model systems constructed, it still remains a
considerable task to scale these up to practical, working
computers. Hitachi said quantum computers could run computation
tasks that were currently either impossible or impractical within a
sensible timescale using classical computers.
Potential applications where quantum computing could be used
include bioinformatics, molecular modelling, codebreaking and
encryption. Quantum computers could also be used as simulators to
solve quantum mechanics problems.