Exploració per tema "Quantum optics"
Ara es mostren els items 21-40 de 92
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Diagrammatic expansions of Hubbard models
(Universitat Politècnica de Catalunya, 2016-06-19)
Treball Final de Grau
Accés obertOptical lattice are periodic structures made of light, they are formed by the interference of laser beams producing standing waves. The depth and the periodicity of the optical lattice can be highly controlled, therefore, ... -
Digital coherent receiver for orbital angular momentum demultiplexing
(2013-01-15)
Article
Accés obertWe put forward a type of receiver for coherent detection of the photon orbital angular momentum (OAM). A coherent array receiver, consisting of multiple subapertures, with each subaperture coupled to a single-mode fiber, ... -
Dynamics of a Bose Einstein condensate in a ring potential
(Universitat Politècnica de Catalunya / Universitat Autònoma de Barcelona, 2012-09-04)
Projecte Final de Màster Oficial
Accés obert[ANGLÈS] We have addressed the dynamics of a repulsive interacting 87 Rb Bose Einstein condensate (BEC) in a ring potential trap. Our study has been focused in the analysis of the interference pattern that arises by the ... -
Dynamics of matter wave solitons
(Universitat Politècnica de Catalunya / Universitat Autònoma de Barcelona, 2012-09-04)
Projecte Final de Màster Oficial
Accés obert[ANGLÈS] We study the implementation of a matter wave bright soliton interferometer formed by a Gaussian potential barrier placed at the center of a harmonic trap potential. After numerically evaluating the transmission ... -
Efficient generation of new optical wavelengths by means of second harmonic generation in AlGaAs Bragg reflection waveguides
(Universitat Politècnica de Catalunya, 2011-09-19)
Projecte/Treball Final de Carrera
Accés obertEnglish: In this project has been designed and implemented a setup to produce the nonlinear process of the second harmonic generation (SHG) in Bragg reflection waveguides (BRW). Starting with the adjustment of a tunable ... -
Efficient heralding of polarization-entangled photons from type-0 and type-II spontaneous parametric downconversion in periodically poled KTiOPO 4
(2014-09-01)
Article
Accés restringit per política de l'editorialUltrabright sources of entangled photon pairs with high heralding efficiency are an important step in the pursuit of high-bit-rate entanglement-base quantum key distribution, as well as an enabling tool for loss-sensitive ... -
Entangled Photon Source for Single Molecule Microscopy
(Universitat Politècnica de Catalunya, 2013-02-11)
Projecte Final de Màster Oficial
Accés obert[ANGLÈS] This paper presents experimental implementation of highly correlated photons for single molecules microscopy application. We designed and built a Type-II Spontaneous Parametric Down Conversion (SPDC) photon pair ... -
Entanglement and Nonlocality are Inequivalent for Any Number of Parties
(APS, 2015-07-15)
Article
Accés obertUnderstanding the relation between nonlocality and entanglement is one of the fundamental problems in quantum physics. In the bipartite case, it is known that these two phenomena are inequivalent, as there exist entangled ... -
Flux enhancement of photons entangled in orbital angular momentum
(2011-07-18)
Article
Accés restringit per política de l'editorialEntangled photons are generally collected by detection systems that select their certain spatial modes, for example using single-mode optical fibers. We derive simple and easy-to-use expressions that allow us to maximize ... -
Fragmented condensation in Bose–Hubbard trimers with tunable tunnelling
(IOP, 2015-07-15)
Article
Accés obertWe consider a Bose–Hubbard (BH) trimer, i.e. an ultracold Bose gas populating three quantum states. The latter can be either different sites of a triple-well potential or three internal states of the atoms. The bosons can ... -
Frequency conversion of structured light
(Macmillan Publishers, 2016-02-15)
Article
Accés obertCoherent frequency conversion of structured light, i.e. the ability to manipulate the carrier frequency of a wave front without distorting its spatial phase and intensity profile, provides the opportunity for numerous novel ... -
Generation of polarization entangled photon pairs in Bragg reflection waveguides
(Universitat Politècnica de Catalunya, 2012-09-06)
Projecte Final de Màster Oficial
Accés obert[ANGLÈS] We report the observation of polarization entangled photon pairs generated by means of type-II spontaneous parametric down-conversion (SPDC) within an AlGaAs Bragg reflection waveguide (BRW). Even though SPDC in ... -
Globally-linked vortex clusters
(Kluwer, 2004-09-30)
Capítol de llibre
Accés restringit per política de l'editorialWe show the existence of a rich variety of fully stationary vortex structures made of an increasing number of vortices nested in paraxial wave fields confined by symmetric and asymmetric harmonic trapping potentials in ... -
Green-pumped continuous-wave parametric oscillator based on fanout–grating MgO:PPLN
(2020-12-01)
Article
Accés obertWe report the first green-pumped continuous-wave (cw) optical parametric oscillator (OPO) based on MgO:PPLN in a fanout grating design. Pumped by a single-frequency cw laser at 532 nm, the OPO provides tunable radiation ... -
Harnessing magneto-electric interference to direct light emission with a split-ring resonator
(Universitat Politècnica de Catalunya, 2012-09-03)
Projecte Final de Màster Oficial
Accés obert[ANGLÈS] Here we show that a split-ring resonator, a structure widely known for its magnetic response at optical frequencies, can be used as a robust, unidirectional and broadband nanoantenna. By customizing its dimensions ... -
Improved Quantum Magnetometry beyond the Standard Quantum Limit
(APS, 2015-07-22)
Article
Accés obertUnder ideal conditions, quantum metrology promises a precision gain over classical techniques scaling quadratically with the number of probe particles. At the same time, no-go results have shown that generic, uncorrelated ... -
Insights into Q2Qbar2 states from an effective perspective
(American Physical Society, 2015-10-07)
Article
Accés obertWe discuss the two-photon coupling of the lightest scalar meson on the basis of an extension of χPT. Using low-energy data on the pion form factor and the γγ→π+π−(π0π0) cross sections as inputs, we find Γ(σ→γγ)≅0.126 keV. ... -
Laser frequency stabilization to excited Rydberg transitions using electromagnetically induced transparency
(Universitat Politècnica de Catalunya, 2012-09-10)
Projecte Final de Màster Oficial
Accés obert[ANGLÈS] Rydberg atoms with principal quantum number n>>1 have extraordinary atomic properties including tunable long range dipole-dipole interactions that lead to the so called Rydberg blockade. Atoms excited to these ... -
Locality of temperature in spin chains
(IOP, 2015-08-18)
Article
Accés obertIn traditional thermodynamics, temperature is a local quantity: a subsystem of a large thermal system is in a thermal state at the same temperature as the original system. For strongly interacting systems, however, the ... -
Long-lived spin coherence of indirect excitons in GaAs coupled quantum wells
(IOP, 2015-04-30)
Article
Accés obertWe study spatially indirect excitons confined in a symmetric GaAs double quantum well. We show that the spin polarisation of very dilute gases can be optically imprinted, in both pure and superposition states. In the regime ...
