6 research outputs found
Entanglement in Bipartite Quantum Systems with Fast Local Unitary Control
The well-known Schmidt decomposition, or equivalently, the complex singular
value decomposition, states that a pure quantum state of a bipartite system can
always be brought into a "diagonal" form using local unitary transformations.
In this work we consider a finite-dimensional closed bipartite system with fast
local unitary control. In this setting one can define a reduced control system
on the singular values of the state which is equivalent to the original control
system. We explicitly describe this reduced control system and prove
equivalence to the original system. Moreover, using the reduced control system,
we prove that the original system is controllable and stabilizable and we
deduce quantum speed limits. We also treat the fermionic and bosonic cases in
parallel, which are related to the Autonne-Takagi and Hua factorization
respectively.Comment: 21 page
Quantum optimal control in quantum technologies. Strategic report on current status, visions and goals for research in Europe
Quantum optimal control, a toolbox for devising and implementing the shapes
of external fields that accomplish given tasks in the operation of a quantum
device in the best way possible, has evolved into one of the cornerstones for
enabling quantum technologies. The last few years have seen a rapid evolution
and expansion of the field. We review here recent progress in our understanding
of the controllability of open quantum systems and in the development and
application of quantum control techniques to quantum technologies. We also
address key challenges and sketch a roadmap for future developments.Comment: this is a living document - we welcome feedback and discussio
Quantum optimal control in quantum technologies. Strategic report on current status, visions and goals for research in Europe
Quantum optimal control, a toolbox for devising and implementing the shapes of external fields that accomplish given tasks in the operation of a quantum device in the best way possible, has evolved into one of the cornerstones for enabling quantum technologies. The last few years have seen a rapid evolution and expansion of the field. We review here recent progress in our understanding of the controllability of open quantum systems and in the development and application of quantum control techniques to quantum technologies. We also address key challenges and sketch a roadmap for future developments
Characterization of Majorization Monotone Quantum Dynamics
In this technical note, the author studies the dynamics of open quantum system in Markovian environment. The author gives necessary and sufficient conditions for such dynamics to be majorization monotone, which are those dynamics always mixing the states