531 research outputs found
On the spectroscopy of quantum dots in microcavities
At the occasion of the OECS conference in Madrid, we give a succinct account
of some recent predictions in the spectroscopy of a quantum dot in a
microcavity that remain to be observed experimentally, sometimes within the
reach of the current state of the art.Comment: OECS11 Conference proceedings, in editor style. 4 pages, 1 figure.
Animations provided separatel
Mesoscopic entanglement induced by spontaneous emission in solid-state quantum optics
Implementations of solid-state quantum optics provide us with devices where qubits are placed at fixed positions in photonic or plasmonic one-dimensional waveguides. We show that solely by controlling the position ofthe qubits and withthe help of a coherent driving, collective spontaneous decay may be engineered to yield an entangled mesoscopic steady state. Our scheme relies on the realization of pure superradiant Dicke models by a destructive interference that cancels dipole-dipole interactions in one dimension
Generation of a two-photon state from a quantum dot in a microcavity under incoherent and coherent continuous excitation
We analyze the impact of both an incoherent and a coherent continuous
excitation on our proposal to generate a two-photon state from a quantum dot in
a microcavity [New J. Phys. 13, 113014 (2011)]. A comparison between exact
numerical results and analytical formulas provides the conditions to
efficiently generate indistinguishable and simultaneous pairs of photons under
both types of excitation.Comment: 10 pages, 3 figures, conference proceeding
Optimization of photon correlations by frequency filtering
Photon correlations are a cornerstone of Quantum Optics. Recent works [NJP 15
025019, 033036 (2013), PRA 90 052111 (2014)] have shown that by keeping track
of the frequency of the photons, rich landscapes of correlations are revealed.
Stronger correlations are usually found where the system emission is weak.
Here, we characterize both the strength and signal of such correlations,
through the introduction of the 'frequency resolved Mandel parameter'. We study
a plethora of nonlinear quantum systems, showing how one can substantially
optimize correlations by combining parameters such as pumping, filtering
windows and time delay.Comment: Small updates to take into account the recent experimental
observation of the physics here analyze
Theory of frequency-filtered and time-resolved N-photon correlations
A theory of correlations between N photons of given frequencies and detected
at given time delays is presented. These correlation functions are usually too
cumbersome to be computed explicitly. We show that they are obtained exactly
through intensity correlations between two-level sensors in the limit of their
vanishing coupling to the system. This allows the computation of correlation
functions hitherto unreachable. The uncertainties in time and frequency of the
detection, which are necessary variables to describe the system, are intrinsic
to the theory. We illustrate the formalism with the Jaynes--Cummings model,
showing how correlations of various peaks at zero or finite time delays bring
new insights into the dynamics of open quantum systems.Comment: 12 pages, 2 figure
Two-photon spectra of quantum emitters
We apply our recently developed theory of frequency-filtered and
time-resolved N-photon correlations to study the two-photon spectra of a
variety of systems of increasing complexity: single mode emitters with two
limiting statistics (one harmonic oscillator or a two-level system) and the
various combinations that arise from their coupling. We consider both the
linear and nonlinear regimes under incoherent excitation. We find that even the
simplest systems display a rich dynamics of emission, not accessible by simple
single photon spectroscopy. In the strong coupling regime, novel two-photon
emission processes involving virtual states are revealed. Furthermore, two
general results are unraveled by two-photon correlations with narrow linewidth
detectors: i) filtering induced bunching and ii) breakdown of the
semi-classical theory. We show how to overcome this shortcoming in a
fully-quantized picture.Comment: 27 pages, 8 figure
Linear and nonlinear coupling of quantum dots in microcavities
We discuss the topical and fundamental problem of strong-coupling between a
quantum dot an the single mode of a microcavity. We report seminal quantitative
descriptions of experimental data, both in the linear and in the nonlinear
regimes, based on a theoretical model that includes pumping and quantum
statistics.Comment: Proceedings of the symposium Nanostructures: Physics and Technology
2010 (http://www.ioffe.ru/NANO2010), 2 pages in proceedings styl
Photon-mediated interactions near a Dirac photonic crystal slab
Dirac energy-dispersions are responsible of the extraordinary transport
properties of graphene. This motivated the quest for engineering such energy
dispersions also in photonics, where they have been predicted to lead to many
exciting phenomena. One paradigmatic example is the possibility of obtaining
power-law, decoherence-free, photon-mediated interactions between quantum
emitters when they interact with such photonic baths. This prediction, however,
has been obtained either by using toy-model baths, which neglect polarization
effects, or by restricting the emitter position to high-symmetry points of the
unit cell in the case of realistic structures. Here, we develop a
semi-analytical theory of dipole radiation near photonic Dirac points in
realistic structures that allows us to compute the effective photon-mediated
interactions along the whole unit cell. Using this theory, we are able to find
the positions that maximize the emitter interactions and their range, finding a
trade-off between them. Besides, using the polarization degree of freedom, we
also find positions where the nature of the collective interactions change from
being coherent to dissipative ones. Thus, our results significantly improve the
knowledge of Dirac light-matter interfaces, and can serve as a guidance for
future experimental designs.Comment: 12 figures, 19 page
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