Suchergebnisse

People make decisions on how to spend scarce money and time on transport, reflecting in this way not only their mobility needs but also their options and preferences. On the other hand, government and operators seek users to adopt travel patterns which have a positive impact on transportation systems and the environment through strategic investments and policies. Parkand-ride are facilities that promote the use of rail transit, encouraging a transfer of commuters from car to public transport. The aim of this thesis is to investigate the effect of increasing parking charges at park-and-ride facilities on park-and-ride users and the impact on other complementary transportation modes for the Chicago Area according to the spatial configuration of the city. To address this objective, STOPS software, released by the Federal Transit Administration of US will be used as a tool for travel demand forecasting. It will be performed a pricing sensibility analysis to evaluate price sensitivity on travel demand. This study provides a new insight in park-and-ride price elasticities for big cities that contributes to a literature of little extend in this field. In particular for the Chicago metropolitan area, this thesis provides a new assessment tool to improve park-and-ride management in the region and operator's performance towards a more sustainable and transit-oriented city. ; El temps i els diners emprats en el transport influeixen en les decisions dels usuaris, determinant així, no només les seves necessitats de mobilitat sinó també les diferents possibles opcions i preferències. Per altre banda, l'administració i els operadors del transport apliquen estratègies i polítiques que influencien als usuaris a optar cap a models de transport més sostenibles i beneficiosos pel sistema. Els Park-and-ride es tracten de facilitats que promouen l'ús de la xarxa de trens o busos, motivant als usuaris a passar de l'ús del cotxe al transport públic. L'objectiu d'aquest treball és investigar l'efecte de l'increment del preu en les tarifes d'aquests serveis de pàrquing i l'impacte sobre els usuaris que utilitzen aquests serveis i també l'impacte sobre altres modes de transport complementaris a la ciutat de Chicago, en relació a la configuració espacial de la ciutat. Per fer aquest estudi s'ha utilitzat un software anomenat STOPS, producte de la Federal Transit Administration d'Estats Units. S'ha realitzat un anàlisis de sensibilitat de demanda en relació als preus per avaluar la sensibilitat del usuaris a aquests canvis. Aquest estudi és una nova aportació a la literatura referida a l'elasticitat de preus en aquest camp. A més, per l'àrea metropolitana de Chicago, aquest projecte serveix com una eina per la presa de decisions a l'hora de gestionar aquestes infraestructures i millorar la eficiència de l'operadora per avançar cap un model de ciutat més sostenible, enfocat a l'ús del transport públic.

People make decisions on how to spend scarce money and time on transport, reflecting in this way not only their mobility needs but also their options and preferences. On the other hand, government and operators seek users to adopt travel patterns which have a positive impact on transportation systems and the environment through strategic investments and policies. Parkand-ride are facilities that promote the use of rail transit, encouraging a transfer of commuters from car to public transport. The aim of this thesis is to investigate the effect of increasing parking charges at park-and-ride facilities on park-and-ride users and the impact on other complementary transportation modes for the Chicago Area according to the spatial configuration of the city. To address this objective, STOPS software, released by the Federal Transit Administration of US will be used as a tool for travel demand forecasting. It will be performed a pricing sensibility analysis to evaluate price sensitivity on travel demand. This study provides a new insight in park-and-ride price elasticities for big cities that contributes to a literature of little extend in this field. In particular for the Chicago metropolitan area, this thesis provides a new assessment tool to improve park-and-ride management in the region and operator's performance towards a more sustainable and transit-oriented city. ; El temps i els diners emprats en el transport influeixen en les decisions dels usuaris, determinant així, no només les seves necessitats de mobilitat sinó també les diferents possibles opcions i preferències. Per altre banda, l'administració i els operadors del transport apliquen estratègies i polítiques que influencien als usuaris a optar cap a models de transport més sostenibles i beneficiosos pel sistema. Els Park-and-ride es tracten de facilitats que promouen l'ús de la xarxa de trens o busos, motivant als usuaris a passar de l'ús del cotxe al transport públic. L'objectiu d'aquest treball és investigar l'efecte de l'increment del preu en les tarifes d'aquests serveis de pàrquing i l'impacte sobre els usuaris que utilitzen aquests serveis i també l'impacte sobre altres modes de transport complementaris a la ciutat de Chicago, en relació a la configuració espacial de la ciutat. Per fer aquest estudi s'ha utilitzat un software anomenat STOPS, producte de la Federal Transit Administration d'Estats Units. S'ha realitzat un anàlisis de sensibilitat de demanda en relació als preus per avaluar la sensibilitat del usuaris a aquests canvis. Aquest estudi és una nova aportació a la literatura referida a l'elasticitat de preus en aquest camp. A més, per l'àrea metropolitana de Chicago, aquest projecte serveix com una eina per la presa de decisions a l'hora de gestionar aquestes infraestructures i millorar la eficiència de l'operadora per avançar cap un model de ciutat més sostenible, enfocat a l'ús del transport públic.

This work was supported by the FWF (P 29603), the Linz Institute of Technology, the BMBF (Q.com-H, Contract No. 16KIS0108), the EU project HANAS (No. 601126210), AWS Austria Wirtschaftsservice (PRIZE Programme, Grant No. P1308457), and the European Research Council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (SPQRel, Grant Agreement No. 679183). X. Yuan was supported by China Scholarship Council (CSC, No. 201306090010). V. Křápek was supported by MEYS CR, Project (No. LQ1601). J. Martín-Sánchez acknowledges the Clarín Programme from the Government of the Principality of Asturias and the Marie Curie-COFUND actions PA-18-ACB17-29. We thank J. Claudon (CEA, Grenoble), S. Portalupi (University Stuttgart), and M.A. Dupertuis (EPFL, Lausanne) for fruitful discussions; ; Yuan, X., Weyhausen-Brinkmann, F., Martín-Sánchez, J., Piredda, G., Křápek, V., Huo, Y., Huang, H., Schimpf, C., Schmidt, O.G., Edlinger, J., Bester, G., Trotta, R., Rastelli, A.

Spanish Ministry of Economy, Industry and Competitiveness (national projects MAT2015-65525-R, FIS2014-60195-JIN, MAT2017-88358-C3-3-R, MAT2014-53432-C5-4-R, and the project MDM2016-0618 of the Maria de Maeztu Units of Excellence Programme). P.A.-G. acknowledges support from the European Research Council under Starting Grant 715496, 2DNANOPTICA. J.M.-S. acknowledges support through the Clarín Programme from the Government of the Principality of Asturias and a Marie Curie-COFUND grant (PA-18-ACB17-29). P.L. acknowledges support from a Marie Sklodowska-Cuire individual fellowship (SGPCM-705960) ; Ma, W., Alonso-González, P., Li, S., Nikitin, A.Y., Yuan, J., Martín-Sánchez, J., Taboada-Gutiérrez, J., Amenabar, I., Li, P., Vélez, S., Tollan, C., Dai, Z., Zhang, Y., Sriram, S., Kalantar-Zadeh, K., Lee, S.-T., Hillenbrand, R., Bao, Q.

The work was supported financially by the European Union Seventh Framework Program 209 (FP7/2007-2013) under Grant Agreement No. 601126 210 (HANAS), the AWS Austria Wirtschaftsservice, PRIZE Programme, under Grant No. P1308457, the European Research Council (ERC) under the European Unions Horizon 2020 research and innovation programme (SPQRel, Grant Agreement No. 679183), and the Christian Doppler Gesellschaft under the "Josef Ressel Zentrum für Materialbearbeitung mit ultrakurz gepulsten Laserquellen". J.M.-S. acknowledges support from the Government of the Principality of Asturias and the European Union through a Clarín Marie Curie-COFUND grant (PA-18-ACB17-29).

This project has received funding from the Swiss National Science Foundation research grant (Project Grant No. 200021_165784). MDL acknowledges support from the Swiss National Science Foundation Ambizione grant (Grant No. PZ00P2_179801). RR acknowledges financial support by the Ministerio de Economia, Industria y Competitividad (MINECO) under grant FEDER-MAT2017-90024-P and the Severo Ochoa Centres of Excellence Program under grant SEV-2015-0496 and by the Generalitat de Catalunya under Grant No. 2017 SGR 1506. XC acknowledges financial support by the Ministerio de Economia, Industria y Competitividad under grant TEC2015-67462-C2-1-R (MINECO/FEDER), the Ministerio de Ciencia, Innovacion y Universidades under Grant No. RTI2018-097876-B-C21 (MCIU/AEI/FEDER, UE), and the EU Horizon2020 research and innovation program under Grant No. GrapheneCore2 785219. MLS is funded through a Juan de la Cierva fellowship. JM-S acknowledges support through the Clarin Programme from the Government of the Principality of Asturias and a Marie CurieCOFUND European Grant (PA-18-ACB17-29). RT Acknowledges support by European Union's Horizon 2020 research and innovation programme (SPQRel Grant Agreement No. 679183)

This work has been financially supported by the Spanish Ministerio de Ciencia e Innovación through grant RTI2018-096498-B-I00 (MCIU/AEI/FEDER, UE). Support by the EC's Horizon 2020 Research and Innovation Programme (grant 645776), by the Austrian Science Fund (FWF) (P24471 and P26830), and by the NATO Science for Peace Programme (grant 984735) is acknowledged. A.M-J. acknowledges the financial support through BES-2013-062593. J.M-S acknowledges financial support through the Ramón y Cajal Program from the Government of Spain and FSE (RYC2018-026196-I). We acknowledge support of the publication fee by the Austrian Science Fund (FWF) Der Wissenschaftsfonds Open Access Publication Support Initiative.

We acknowledge funding by the DFG within the Projects No. SCHN1376-5.1 and No. PR1749/1-1. Further, we acknowledge financial support by the State of Bavaria and the German Ministry of Education and Research (BMBF) within the project Q.Link.X (FKZ 16KIS0871). Project HYPER-U-P-S has received funding from the QuantERA ERA-NET Cofund in Quantum Technologies implemented within the European Union's Horizon 2020 Programme. A.P. would like to thank the Swedish Research Council and Carl Tryggers Stiftelse. J.M.-S. acknowledges financial support from the Ramón y Cajal Program from the Government of Spain (RYC2018-026196-I) and the Clarín Programme from the Government of the Principality of Asturias and a Marie Curie-COFUND Grant (PA-18-ACB17-29).

Strain tuning emerged as an appealing tool for tuning of fundamental optical properties of solid-state quantum emitters. In particular, the wavelength and fine structure of quantum dot states can be tuned using hybrid semiconductor-piezoelectric devices. Here, we show how an applied external stress can directly impact the polarization properties of coupled InAs quantum dot-micropillar cavity systems. In our experiment, we find that we can reversibly tune the anisotropic polarization splitting of the fundamental microcavity mode by approximately 60 μeV. We discuss the origin of this tuning mechanism, which arises from an interplay between elastic deformation and the photoelastic effect in our micropillar. Finally, we exploit this effect to tune the quantum dot polarization optomechanically via the polarization-anisotropic Purcell effect. Our work paves the way for optomechanical and reversible tuning of the polarization and spin properties of light-matter-coupled solid-state systems. ; We acknowledge funding by the DFG within the Projects No. SCHN1376-5.1 and No. PR1749/1-1. Further, we acknowledge financial support by the State of Bavaria and the German Ministry of Education and Research (BMBF) within the project Q.Link.X (FKZ 16KIS0871). Project HYPER-U-P-S has received funding from the QuantERA ERA-NET Cofund in Quantum Technologies implemented within the European Union's Horizon 2020 Programme. A.P. would like to thank the Swedish Research Council and Carl Tryggers Stiftelse. J.M.-S. acknowledges financial support from the Ramón y Cajal Program from the Government of Spain (RYC2018-026196-I) and the ClarínProgramme from the Government of the Principality of Asturias and a Marie Curie-COFUND Grant (PA-18-ACB17-29). ; Peer reviewed

Regional Government of the Principality of Asturias [PA20-PF-BP19-053, PA-18-PF-BP17-126]; Ministry of Science and Higher Education of the Russian Federation [0714-2020-0002]; Ramón y Cajal Program from the Government of Spain; FSE, European Social Fund (ESF) [RYC2018-026196-I]; Spanish Ministry of Science, Innovation and Universities [national project no. MAT201788358-C3-3-R]

P.A.-M. acknowledges financial support through JAE Intro program from the Superior Council of Scientific Investigations and the Spanish Ministry of Science and Innovation (grant number JAEINT_20_00589). G.Á.-P. and J.T.-G. acknowledge financial support through the Severo Ochoa Program from the Government of the Principality of Asturias (grant numbers PA-20-PF-BP19-053 and PA-18-PF-BP17-126, respectively). J.M.-S. acknowledges financial support from the Ramón y Cajal Program of the Government of Spain (RYC2018-026196-I) and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant number PID2019-110308GA-I00). P.A.-G. acknowledges support from the European Research Council under starting grant no. 715496, 2DNANOPTICA and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant number PID2019-111156GB-I00).

Polaritons with directional in-plane propagation and ultralow losses in van der Waals (vdW) crystals promise unprecedented manipulation of light at the nanoscale. However, these polaritons present a crucial limitation: their directional propagation is intrinsically determined by the crystal structure of the host material, imposing forbidden directions of propagation. Here, we demonstrate that directional polaritons (in-plane hyperbolic phonon polaritons) in a vdW crystal (α-phase molybdenum trioxide) can be directed along forbidden directions by inducing an optical topological transition, which emerges when the slab is placed on a substrate with a given negative permittivity (4H–silicon carbide). By visualizing the transition in real space, we observe exotic polaritonic states between mutually orthogonal hyperbolic regimes, which unveil the topological origin of the transition: a gap opening in the dispersion. This work provides insights into optical topological transitions in vdW crystals, which introduce a route to direct light at the nanoscale. ; G.Á.-P. and J.T.-G. acknowledge support through the Severo Ochoa Program from the government of the Principality of Asturias (grant nos. PA20-PF-BP19-053 and PA-18-PF-BP17-126, respectively). K.V.V. and V.S.V. acknowledge the Ministry of Science and Higher Education of the Russian Federation (no. 0714-2020-0002). J. M.-S. acknowledges financial support through the Ramón y Cajal Program from the government of Spain and FSE (RYC2018-026196-I). A.Y.N. acknowledges the Spanish Ministry of Science, Innovation and Universities (national project no. MAT201788358-C3-3-R), and the Basque Department of Education (PIBA-2020-1-0014). P.A.-G. acknowledges support from the European Research Council under starting grant no. 715496, 2DNANOPTICA. ; Peer reviewed

This article belongs to the Special Issue 2D Materials and Their Heterostructures and Superlattices. ; Layered materials in which individual atomic layers are bonded by weak van der Waals forces (vdW materials) constitute one of the most prominent platforms for materials research. Particularly, polar vdW crystals, such as hexagonal boron nitride (h-BN), alpha-molybdenum trioxide (α-MoO3) or alpha-vanadium pentoxide (α-V2O5), have received significant attention in nano-optics, since they support phonon polaritons (PhPs)―light coupled to lattice vibrations― with strong electromagnetic confinement and low optical losses. Recently, correlative far- and near-field studies of α-MoO3 have been demonstrated as an effective strategy to accurately extract the permittivity of this material. Here, we use this accurately characterized and low-loss polaritonic material to sense its local dielectric environment, namely silica (SiO2), one of the most widespread substrates in nanotechnology. By studying the propagation of PhPs on α-MoO3 flakes with different thicknesses laying on SiO2 substrates via near-field microscopy (s-SNOM), we extract locally the infrared permittivity of SiO2. Our work reveals PhPs nanoimaging as a versatile method for the quantitative characterization of the local optical properties of dielectric substrates, crucial for understanding and predicting the response of nanomaterials and for the future scalability of integrated nanophotonic devices. ; P.A.-M. acknowledges financial support through JAE Intro program from the Superior Council of Scientific Investigations and the Spanish Ministry of Science and Innovation (grant number JAEINT_20_00589). G.Á.-P. and J.T.-G. acknowledge financial support through the Severo Ochoa Program from the Government of the Principality of Asturias (grant numbers PA-20-PF-BP19-053 and PA-18-PF-BP17-126, respectively). J.M.-S. acknowledges financial support from the Ramón y Cajal Program of the Government of Spain (RYC2018-026196-I) and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant number PID2019-110308GA-I00). P.A.-G. acknowledges support from the European Research Council under starting grant no. 715496, 2DNANOPTICA and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant number PID2019-111156GB-I00). ; Peer reviewed

Phonon polaritons (PhPs)—light coupled to lattice vibrations—with in-plane hyperbolic dispersion exhibit ray-like propagation with large wave vectors and enhanced density of optical states along certain directions on a surface. As such, they have raised a surge of interest, promising unprecedented manipulation of infrared light at the nanoscale in a planar circuitry. Here, we demonstrate focusing of in-plane hyperbolic PhPs propagating along thin slabs of α-MoO3. To that end, we developed metallic nanoantennas of convex geometries for both efficient launching and focusing of the polaritons. The foci obtained exhibit enhanced near-field confinement and absorption compared to foci produced by in-plane isotropic PhPs. Foci sizes as small as λp/4.5 = λ0/50 were achieved (λp is the polariton wavelength and λ0 is the photon wavelength). Focusing of in-plane hyperbolic polaritons introduces a first and most basic building block developing planar polariton optics using in-plane anisotropic van der Waals materials. ; J.M.-S. acknowledges financial support from the Ramón y Cajal Program of the Government of Spain and FSE (RYC2018-026196-I) and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant number PID2019-110308GA-I00). P.A.-G. acknowledges support from the European Research Council under starting grant no. 715496, 2DNANOPTICA, and the Spanish Ministry of Science and Innovation (State Plan for Scientific and Technical Research and Innovation grant number PID2019-111156GB-I00). J.T.-G. acknowledges support through the Severo Ochoa Program from the Government of the Principality of Asturias (PA-18-PF-BP17-126). G.A.-P. acknowledges support through the Severo Ochoa Program from the Government of the Principality of Asturias (PA-20-PF-BP19-053). K.V.V. and V.S.V. acknowledge the financial support from the Ministry of Science and Higher Education of the Russian Federation (agreement no. 075-15-2021-606). A.Y.N. acknowledges the Spanish Ministry of Science, Innovation, and Universities (national projects MAT2017-88358-C3-3-R and PID2020-115221GB-C42) and the Basque Department of Education (PIBA-2020-1-0014). R.H. acknowledges financial support from the Spanish Ministry of Science, Innovation, and Universities (national project number RTI2018-094830-B-100 and project number MDM-2016-0618 of the Marie de Maeztu Units of Excellence Program) and the Basque Government (grant number IT1164-19). ; Peer reviewed

J.M.-S. acknowledges support through the Cların Programme ́from the Government of the Principality of Asturias and a Marie Curie-COFUND European grant (PA-18-ACB17-29). J.T.-G. acknowledges support through the Severo Ochoa Program from the Goverment of the Principality of Asturias (PA-18-PF-BP17-126). P.A.-G. acknowledges support from the European Research Council under Starting Grant 715496, 2DNANOPTICA. R.T., D.T., and M.S. acknowledge support by the European Research council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (SPQRel, Grant agreement No. 679183). C.S. acknowledges support by the European Research council (ERC) under the European Union's Horizon 2020 Research and Innovation Programme (UnLiMIt-2D, Grant agreement No. 679288). A.R. acknowledges support from the Linz Institute of Technology (LIT). The Würzburg group acknowledges support by the State of Bavaria. S.T. acknowledges support from NSF DMR-1552220, NSF CMMI-1933214 and NSF DMR-1838443.