10,322 research outputs found
Non-reciprocal few-photon devices based on chiral waveguide-emitter couplings
We demonstrate the possibility of designing efficient, non reciprocal
few-photon devices by exploiting the chiral coupling between two waveguide
modes and a single quantum emitter. We show how this system can induce
non-reciprocal photon transport at the single-photon level and act as an
optical diode. Afterwards, we also show how the same system shows a
transistor-like behaviour for a two-photon input. The efficiency in both cases
is shown to be large for feasible experimental implementations. Our results
illustrate the potential of chiral waveguide-emitter couplings for applications
in quantum circuitry.Comment: Mathematica notebook attached for calculation of detection
probabilitie
Non-Markovian effects in waveguide-mediated entanglement
We study the generation and evolution of entanglement between two qubits
coupled through one-dimensional waveguide modes. By using a complete quantum
electrodynamical formalism we go beyond the Markovian approximation. The
diagonalization of the hamiltonian is carried out, and a set of quasi-localized
eigenstates is found. We show that when the qubit-waveguide coupling is
increased, the Markov approximation is not anymore valid, and the generation of
entanglement is worsened.Comment: 13 pages, 7 figure
Bilayer Metasurface: Induced Transparency and Fabry Perot Resonance
A Fabry-Perot resonator utilizes two solid, non-resonating, reflecting
mirrors to form resonant patterns when the separation between the mirrors
satisfies the resonance conditions. The resonant mode concentrates at the
middle of the cavity. In this study, we constructed a Fabry-Perot cavity with
nanostructured resonant metasurfaces as meta-mirrors. The individual
metasurfaces exhibit resonant transmission dips with a minimum transmission and
a quality factor of t0 and Qs, respectively. The coherent interference between
the two metasurfaces changes the behavior of the entire resonant system,
generating an induced transparency in the original spectrum. The sharpness of
the induced transparency peak is linearly related to the group delay of the
single metasurface. Assuming a Lorentzian lineshape, we show that for small t0,
the quality factor of the induced transparency peak is Qs/t0^3. The field
confines to the meta-mirrors region rather than at the middle of the
Fabry-Perot cavity. We provide examples of practical metasurfaces made from
dielectric scatters composed of silicon thin nanodisks and demonstrate high
quality factors and phase dispersion that are unattainable by any nano or
microscale flat optics systems
Entanglement of two qubits mediated by one-dimensional plasmonic waveguides
We investigate qubit-qubit entanglement mediated by plasmons supported by
one-dimensional waveguides. We explore both the situation of spontaneous
formation of entanglement from an unentangled state and the emergence of driven
steady-state entanglement under continuous pumping. In both cases, we show that
large values for the concurrence are attainable for qubit-qubit distances
larger than the operating wavelength by using plasmonic waveguides that are
currently available.Comment: 4 pages, 4 figures. Minor Changes. Journal Reference added.
Highlighted in Physic
From glow-sticks to sensors: Single-electrode electrochemical detection for paper-based devices
With the goal of creating a multipurpose platform for electrogenerated luminescence, a single electrode electrochemical system was designed, developed, and validated. Glow sticks were used as the source of the luminophore, which was used as the optical reporter for the biosensor. A smartphone was used as the detector to quantify the electrochemiluminescence emissions. A disposable paper-based device was designed and used as a two-compartment electrochemical reaction cell, affording the possibility to individually optimize the sensing and detection reactions. This sensor assembly was tested under different conditions, showing acceptable performance both in the determination of hydrogen peroxide concentrations, to evaluate rancidity markers in edible oil samples, and to quantify the glucose concentration in soft drinks. The analytical performance of the single electrode, electrochemiluminescent device showed a limit of detection for hydrogen peroxide of 1.02 µM, with a working range between 0.4 µM and 150 mM. The proposed approach represents the first example of a system that combines paperbased devices, single electrode electrochemistry, electrochemiluminescence, and smartphone image sensing. As such, it not only provides a convenient platform for the development of a variety of analytical applications but also broaden the versatility of ePADs.Fil: Vidal, Ezequiel Martin. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto de QuĂmica del Sur. Universidad Nacional del Sur. Departamento de QuĂmica. Instituto de QuĂmica del Sur; ArgentinaFil: Domini, Claudia Elizabeth. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - BahĂa Blanca. Instituto de QuĂmica del Sur. Universidad Nacional del Sur. Departamento de QuĂmica. Instituto de QuĂmica del Sur; ArgentinaFil: Whitehead, Daniel C.. CLEMSON UNIVERSITY (CLEMSON UNIVERSITY);Fil: Garcia, Carlos D.. CLEMSON UNIVERSITY (CLEMSON UNIVERSITY)
Matrix product decomposition and classical simulation of quantum dynamics in the presence of a symmetry
We propose a refined matrix product state representation for many-body
quantum states that are invariant under SU(2) transformations, and indicate how
to extend the time-evolving block decimation (TEBD) algorithm in order to
simulate time evolution in an SU(2) invariant system. The resulting algorithm
is tested in a critical quantum spin chain and shown to be significantly more
efficient than the standard TEBD.Comment: 5 pages, 4 figure
Perivascular adipocytes and signaling through toll-like receptors: role in the pathophysiology of atherosclerosis
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