1,996 research outputs found
Cloning of a quantum measurement
We analyze quantum algorithms for cloning of a quantum measurement. Our aim
is to mimic two uses of a device performing an unknown von Neumann measurement
with a single use of the device. When the unknown device has to be used before
the bipartite state to be measured is available we talk about 1 -> 2 learning
of the measurement, otherwise the task is called 1 -> 2 cloning of a
measurement. We perform the optimization for both learning and cloning for
arbitrary dimension of the Hilbert space. For 1 -> 2 cloning we also propose a
simple quantum network that realizes the optimal strategy.Comment: 10 pages, 1 figur
Quantum Control Landscapes
Numerous lines of experimental, numerical and analytical evidence indicate
that it is surprisingly easy to locate optimal controls steering quantum
dynamical systems to desired objectives. This has enabled the control of
complex quantum systems despite the expense of solving the Schrodinger equation
in simulations and the complicating effects of environmental decoherence in the
laboratory. Recent work indicates that this simplicity originates in universal
properties of the solution sets to quantum control problems that are
fundamentally different from their classical counterparts. Here, we review
studies that aim to systematically characterize these properties, enabling the
classification of quantum control mechanisms and the design of globally
efficient quantum control algorithms.Comment: 45 pages, 15 figures; International Reviews in Physical Chemistry,
Vol. 26, Iss. 4, pp. 671-735 (2007
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