3,799 research outputs found
Vacuum Stability and Higgs Diphoton Decay Rate in the Zee-Babu Model
Although recent Higgs data from ATLAS and CMS are compatible with a Standard
Model (SM) signal at level, both experiments see indications for an
excess in the diphoton decay channel, which points to new physics beyond the
SM. Given such a low Higgs mass , another sign
indicating the existence of new physics beyond the SM is the vacuum stability
problem, i.e., the SM Higgs quartic coupling may run to negative values at a
scale below the Planck scale. In this paper, we study the vacuum stability and
enhanced Higgs diphoton decay rate in the Zee-Babu model, which was used to
generate tiny Majorana neutrino masses at two-loop level. We find that it is
rather difficult to find overlapping regions allowed by the vacuum stability
and diphoton enhancement constraints. As a consequence, it is almost inevitable
to introduce new ingredients into the model, in order to resolve these two
issues simultaneously.Comment: 19 pages, 6 figure
Quantum-dot single-photon sources for the quantum internet
High-performance quantum light sources based on semiconductor quantum dots
coupled to microcavities are showing their promise in long-distance solid-state
quantum networks.Comment: Invited commentary for Nature Nanotechnology 202
Toolbox for entanglement detection and fidelity estimation
The determination of the state fidelity and the detection of entanglement are
fundamental problems in quantum information experiments. We investigate how
these goals can be achieved with a minimal effort. We show that the fidelity of
GHZ and W states can be determined with an effort increasing only linearly with
the number of qubits. We also present simple and robust methods for other
states, such as cluster states and states in decoherence-free subspaces.Comment: 5 pages, no figures, v3: final version, to appear as a Rapid
Communication in PR
Multi-photon entanglement and interferometry
Multi-photon interference reveals strictly non-classical phenomena. Its
applications range from fundamental tests of quantum mechanics to photonic
quantum information processing, where a significant fraction of key experiments
achieved so far comes from multi-photon state manipulation. We review the
progress, both theoretical and experimental, of this rapidly advancing
research. The emphasis is given to the creation of photonic entanglement of
various forms, tests of the completeness of quantum mechanics (in particular,
violations of local realism), quantum information protocols for quantum
communication (e.g., quantum teleportation, entanglement purification and
quantum repeater), and quantum computation with linear optics. We shall limit
the scope of our review to "few photon" phenomena involving measurements of
discrete observables.Comment: 71 pages, 38 figures; updated version accepted by Rev. Mod. Phy
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