26,243 research outputs found
Non-Markovian Quantum Optics with Three-Dimensional State-Dependent Optical Lattices
Quantum emitters coupled to structured photonic reservoirs experience
unconventional individual and collective dynamics emerging from the interplay
between dimensionality and non-trivial photon energy dispersions. In this work,
we systematically study several paradigmatic three dimensional structured baths
with qualitative differences in their bath spectral density. We discover
non-Markovian individual and collective effects absent in simplified
descriptions, such as perfect subradiant states or long-range anisotropic
interactions. Furthermore, we show how to implement these models using only
cold atoms in state-dependent optical lattices and show how this unconventional
dynamics can be observed with these systems.Comment: 39 pages, 17 figures. Accepted versio
Purely Long-Range Coherent Interactions in Two-Dimensional Structured Baths
In this work we study the quantum dynamics emerging when quantum emitters
exchange excitations with a two-dimensional bosonic bath with hexagonal
symmetry. We show that a single quantum emitter spectrally tuned to the middle
of the band relaxes following a logarithmic law in time due to the existence of
a singular point with vanishing density of states, i.e., the Dirac point.
Moreover, when several emitters are coupled to the bath at that frequency,
long-range coherent interactions between them appear which decay inversely
proportional to their distance without exponential attenuation. We analyze both
the finite and infinite system situation using both perturbative and
non-perturbative methods.Comment: 18 pages, 7 figures. Text restructured. Extended discussion on
experimental consideration
Geometrical resonance in spatiotemporal systems
We generalize the concept of geometrical resonance to perturbed sine-Gordon,
Nonlinear Schrödinger and Complex Ginzburg-Landau equations. Using this
theory we can control different dynamical patterns. For instance, we can
stabilize breathers and oscillatory patterns of large amplitudes successfully
avoiding chaos. On the other hand, this method can be used to suppress
spatiotemporal chaos and turbulence in systems where these phenomena are
already present. This method can be generalized to even more general
spatiotemporal systems.Comment: 2 .epl files. Accepted for publication in Europhysics Letter
Charge control in laterally coupled double quantum dots
We investigate the electronic and optical properties of InAs double quantum
dots grown on GaAs (001) and laterally aligned along the [110] crystal
direction. The emission spectrum has been investigated as a function of a
lateral electric field applied along the quantum dot pair mutual axis. The
number of confined electrons can be controlled with the external bias leading
to sharp energy shifts which we use to identify the emission from neutral and
charged exciton complexes. Quantum tunnelling of these electrons is proposed to
explain the reversed ordering of the trion emission lines as compared to that
of excitons in our system.Comment: 4 pages, 4 figures submitted to PRB Rapid Com
Heralded multiphoton states with coherent spin interactions in waveguide QED
WaveguideQEDoffers the possibility of generating strong coherent atomic
interactions either through appropriate atomic configurations in the
dissipative regime or in the bandgap regime. In this work, we show how to
harness these interactions in order to herald the generation of highly
entangled atomic states, which afterwards can be mapped to generate single mode
multi-photonic states with high fidelities.Weintroduce two protocols for the
preparation of the atomic states, we discuss their performance and compare them
to previous proposals. In particular, we show that one of them reaches high
probability of success for systems with many atoms but low Purcell factors
Interplay of Coulomb and electron-phonon interactions in graphene
We consider mutual effect of the electron-phonon and strong Coulomb
interactions on each other by summing up leading logarithmic corrections via
the renormalization group approach. We find that the Coulomb interaction
enhances electron coupling to the intervalley A1 optical phonons, but not to
the intravalley E2 phonons
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