25 research outputs found
Testing for entanglement with periodic coarse-graining
Continuous variables systems find valuable applications in quantum
information processing. To deal with an infinite-dimensional Hilbert space, one
in general has to handle large numbers of discretized measurements in tasks
such as entanglement detection. Here we employ the continuous transverse
spatial variables of photon pairs to experimentally demonstrate novel
entanglement criteria based on a periodic structure of coarse-grained
measurements. The periodization of the measurements allows for an efficient
evaluation of entanglement using spatial masks acting as mode analyzers over
the entire transverse field distribution of the photons and without the need to
reconstruct the probability densities of the conjugate continuous variables.
Our experimental results demonstrate the utility of the derived criteria with a
success rate in entanglement detection of relative to studied
cases.Comment: V1: revtex4, 10 pages, 4 figures + supp. material (4 pages, 1 figure)
V2: Substantial revisions implemented both in theory and experimental data
analysi
Enhanced Photonic Maxwell's Demon with Correlated Baths
Maxwell's Demon is at the heart of the interrelation between quantum
information processing and thermodynamics. In this thought experiment, a demon
extracts work from two thermal baths at equilibrium by gaining information
about them at the single-particle level and applying classical feed-forward
operations. Here we implement a photonic version of Maxwell's Demon with active
feed-forward in a fiber-based system using ultrafast optical switches. We
experimentally show that, if correlations exist between the two thermal baths,
the Demon can extract over an order of magnitude more work than without
correlations. Our work demonstrates the great potential of photonic experiments
-- which provide a unique degree of control on the system -- to access new
regimes in quantum thermodynamics.Comment: 23 pages with appendix, 6 figure
An Optical Processor Specialized on Matrix Operations
International audienceWe review our very recent results on the development of an optical processor specialized on operations on matrices
An Optical Processor Specialized on Matrix Operations
International audienceWe review our very recent results on the development of an optical processor specialized on operations on matrices
An Optical Processor Specialized on Matrix Operations
International audienceWe review our very recent results on the development of an optical processor specialized on operations on matrices