Exploració per tema "Quantum optics"

Ara es mostren els items 32-51 de 93

    • Generation of polarization entangled photon pairs in Bragg reflection waveguides 

      Vallés Marí, Adam (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 

      Crasovan, L C; Vekslerchik, V; Mihalache, Dumitru; Pérez Torres, Juan; Perez-Garcia, V M; Torner Sabata, Lluís (Kluwer, 2004-09-30)
      Capítol de llibre
      Accés restringit per política de l'editorial
      We 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 

      Sukeert, Sukeert; Kumar Suddapalli, Chaitanya; Ebrahim-Zadeh, Majid (2020-12-01)
      Article
      Accés obert
      We 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 

      Hancu, Ion Michael (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 

      Brask, J. B.; Chaves, R.; Kołodyński, J. (APS, 2015-07-22)
      Article
      Accés obert
      Under 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 

      Ametller Congost, Lluís; Talavera Sánchez, Pedro (American Physical Society, 2015-10-07)
      Article
      Accés obert
      We 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 

      Grimau Puigibert, Marcel·lí (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 

      Hernández-Santana, Senaida; Riera, Arnau; Hovhannisyan, Karen V.; Perarnau-Llobet, Martí; Tagliacozzo, Luca (IOP, 2015-08-18)
      Article
      Accés obert
      In 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 

      Beian, Mussie; Alloing, Mathieu; Cambril, Edmond; Gomez Carbonell, Carmen; Osmond, Johann; Lemaître, Aristide; Dubin, François (IOP, 2015-04-30)
      Article
      Accés obert
      We 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 ...

    • Measurement of noise-induced loss of polarization coherence 

      Jiménez Machado, Gerard (Universitat Politècnica de Catalunya, 2016-10)
      Treball Final de Grau
      Accés restringit per decisió de l'autor
      Experimental implementation of a Quantum-Optical Coherence Tomography (Q-OCT) system, by means of measuring and quantifying induced coherence.

    • Narrowband photon pair source compatible with solid state quantum memories 

      Lago Rivera, Darío (Universitat Politècnica de Catalunya, 2016-09-08)
      Projecte Final de Màster Oficial
      Accés obert
      The generation of narrowband photon pairs compatible with solid state quantum memories is shown and analysed. This study is made in two different steps. In the beginning we implement a photon pair source with a periodically ...

    • New methodology for the Faraday rotation angle retrieval in the SMOS field of view 

      Rubino, Roselena; Duffo Ubeda, Núria; González Gambau, Verónica; Torres Torres, Francisco; Corbella Sanahuja, Ignasi; Martín Neira, Manuel (Institute of Electrical and Electronics Engineers (IEEE), 2018)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      In this work, a new methodology to estimate the Faraday Rotation Angle (FRA) from SMOS full-pol brightness temperature is presented. This approach is focused on retrieving the Vertical Total Electron Content (VTEC) and ...

    • Nonlocality in many-body quantum systems detected with two-body correlators 

      Tura, J.; Augusiak, Remigiusz; Sainz, A. B.; Lücke, B.; Klempt, C.; Lewenstein, Maciej; Acín dal Maschio, Antonio (Science Direct, 2015-07-30)
      Article
      Accés obert
      Contemporary understanding of correlations in quantum many-body systems and in quantum phase transitions is based to a large extent on the recent intensive studies of entanglement in many-body systems. In contrast, much ...

    • Optical coherence tomography with a nonlinear interferometer 

      Sendra Molins, Lluc (Universitat Politècnica de Catalunya, 2018-07-17)
      Projecte Final de Màster Oficial
      Accés obert
      Realitzat a/amb:   Institut de Ciències Fotòniques (ICFO)
      We derive what is the signal and the sensitivity of a nonlinear interferometer (Mach-Zehnder or Michelson), that is a novel approach to perform Optical Coherence Tomography (OCT). The physical idea behind this goes back ...

    • Optical coherence tomography with nonlinear interferometers 

      Kirchner Sala, Helena (Universitat Politècnica de Catalunya, 2021-07-13)
      Treball Final de Grau
      Accés obert
      In recent years, quantum properties of light are opening the door to new applications, especially in communications and high-resolution probing and imaging. Optical coherence tomography (OCT) is an imaging technique ...

    • Optical emulator of two atoms in a double well 

      Fabra Ruiz, Arnau (Universitat Politècnica de Catalunya, 2019-09-09)
      Projecte Final de Màster Oficial
      Accés obert
      We show that optical fibers with an inhomogeneous refractive index profile and thin metallic slabs can be used to simulate a one dimensional system of two interacting particles in a double well. We first study the single ...

    • Optical sectioning in induced coherence tomography with frequency-entangled photons 

      Valles Marin, Adam; Jiménez Machado, Gerard; Salazar Serrano, Luis Jose; Pérez Torres, Juan (American Physical Society, 2018-02-14)
      Article
      Accés obert
      We demonstrate a different scheme to perform optical sectioning of a sample based on the concept of induced coherence [Zou et al., Phys. Rev. Lett. 67, 318 (1991)]. This can be viewed as a different type of optical coherence ...

    • Optomechanical strong coupling between a single photon and a single atom 

      Argüello Luengo, Javier; Chang, Darrick E. (2022-02-01)
      Article
      Accés obert
      Single atoms coupled to a cavity offer unique opportunities as quantum optomechanical devices because of their small mass and strong interaction with light. A particular regime of interest in optomechanics is that of ...

    • Phase Diffusion effects in InP semiconductor lasers 

      Martínez Pàmias, Berta (Universitat Politècnica de Catalunya, 2022-09-06)
      Projecte Final de Màster Oficial
      Accés restringit per acord de confidencialitat

    • Practical implementation of a continuous-variable quantum key distribution system 

      Hernández Aguirre, Leiza (Universitat Politècnica de Catalunya, 2018-06-26)
      Treball Final de Grau
      Accés restringit per decisió de l'autor
      Realitzat a/amb:   Institut de Ciències Fotòniques (ICFO)
      Quantum key distribution with continuous variables (CV-QKD) enables two parties to share a secret key by using coherent states of light and homodyne detection. This can be carried out by employing low-cost and mature ...