Maths for improved quantum control
EU-funded research has produced novel formulations of causal relationships at the quantum scale. The theoretical tools will make a major contribution to both fundamental understanding of quantum physics and to development of quantum devices.
Quantum systems are being developed for numerous applications including
high-precision measurement and control, computation and light
generation. EU-funded scientists set out to develop novel methods
compatible with the quantum world through work on the project 'Quantum
control and error correction with discrete and continuous variables'
QCEC has contributed results with important implications for the
foundations of quantum theory, quantum information processing and the
fundamental problem of unifying quantum theory with general relativity. A
major line of inquiry investigated causal order, one of the most
fundamental concepts of our Universe and of time - in essence the
requirement that an effect comes after its cause.
Scientists reported in Nature Communications that, using a new
framework they developed, quantum correlations with no causal order can
occur. They also showed that in a classical limit causal order always
arises, suggesting that space-time can emerge from a more fundamental
structure. Building on this, an important study produced an operational
formulation of quantum theory without any predefined time or causal
structure. The framework can also describe exotic causal relations such
as those expected to exist in the context of quantum gravity.
An important difference in quantum control versus classical control
is that the measurement itself changes the dynamics of the system and
introduces noise and non-linear components. Scientists made major
advances in quantum feedback control and error correction providing new
tools for the manipulation of quantum information and its protection
The development of quantum devices for a variety of applications in
basic research and industry has become the focus of more and more
research. QCEC results regarding causal order, feedback control and
error correction in quantum systems could not be more important relevant
with exciting new discoveries and developments expected in the near
last modification: 2015-03-17 07:38:22