5,580 research outputs found
Quantum information processing with space-division multiplexing optical fibres
The optical fibre is an essential tool for our communication infrastructure
since it is the main transmission channel for optical communications. The
latest major advance in optical fibre technology is spatial division
multiplexing (SDM), where new fibre designs and components establish multiple
co-existing data channels based on light propagation over distinct transverse
optical modes. Simultaneously, there have been many recent developments in the
field of quantum information processing (QIP), with novel protocols and devices
in areas such as computing, communication and metrology. Here, we review recent
works implementing QIP protocols with SDM optical fibres, and discuss new
possibilities for manipulating quantum systems based on this technology.Comment: Originally submitted version. Please see published version for
improved layout, new tables and updated references following review proces
Hybrid photonic entanglement: Realization, characterization and applications
We show that the quantum disentanglement eraser implemented on a two-photon
system from parametric down-conversion is a general method to create hybrid
photonic entanglement, namely the entanglement between different degrees of
freedom of the photon pair. To demonstrate this, we generate and characterize a
source with tunable degree of hybrid entanglement between two qubits, one
encoded in the transverse momentum and position of a photon, and the other in
the polarization of its partner. In addition, we show that a simple extension
of our setup enables the generation of two-photon qubit-qudit hybrid entangled
states. Finally, we discuss the advantages that this type of entanglement can
bring for an optical quantum network.Comment: Published versio
New Strongly Coupled Sector at the Tevatron and the LHC
We examine the possibility that a new strong interaction is accessible to the
Tevatron and the LHC. In an effective theory approach, we consider a scenario
with a new color-octet interaction with strong couplings to the top quark, as
well as the presence of a strongly coupled fourth-generation which could be
responsible for electroweak symmetry breaking. We apply several constraints,
including the ones from flavor physics. We study the phenomenology of the
resulting parameter space at the Tevatron, focusing on the the forward-backward
asymmetry in top pair production, as well as in the production of the
fourth-generation quarks. We show that if the excess in the top production
asymmetry is indeed the result of this new interaction, the Tevatron could see
the first hints of the strongly coupled fourth-generation quarks. Finally, we
show that the LHC with TeV and integrated
luminosity should observe the production of fourth-generation quarks at a level
at least one order of magnitude above the QCD prediction for the production of
these states.Comment: 8 pages, 12 figure
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