Université de Fribourg

Transition from light diffusion to localization in three-dimensional amorphous dielectric networks near the band edge

Haberko, Jakub ; Froufe-Pérez, Luis S. ; Scheffold, Frank

In: Nature Communications, 2020, vol. 11, no. 1, p. 4867

AbstractLocalization of light is the photon analog of electron localization in disordered lattices, for whose discovery Anderson received the Nobel prize in 1977. The question about its existence in open three-dimensional materials has eluded an experimental and full theoretical verification for decades. Here we study numerically electromagnetic vector wave transmittance through realistic...

Université de Fribourg

Experimental tuning of transport regimes in hyperuniform disordered photonic materials

Aubry, Geoffroy J. ; Froufe-Pérez, Luis S. ; Kuhl, Ulrich ; Legrand, Olivier ; Scheffold, Frank ; Mortessagne, Fabrice

In: Physical Review Letters, 2020, vol. 125, no. 12, p. 127402

We present wave transport experiments in hyperuniform disordered arrays of cylinders with high dielectric permittivity. Using microwaves, we show that the same material can display transparency, photon diffusion, Anderson localization, or a full band gap, depending on the frequency ν of the electromagnetic wave. Interestingly, we find a second weaker band gap, which appears to be related to...

Université de Fribourg

Light induced inverse-square law interactions between nanoparticles: “mock gravity” at the nanoscale

Luis-Hita, J. ; Marqués, M. I. ; Delgado-Buscalioni, R. ; Sousa, N. de ; Froufe-Pérez, Luis S. ; Scheffold, Frank ; Sáenz, J. J.

In: Physical Review Letters, 2019, vol. 123, no. 14, p. 143201

The interaction forces between identical resonant molecules or nanoparticles, optically induced by a quasimonochromatic isotropic random light field, are theoretically analyzed. In general, the interaction force exhibits a far-field oscillatory behavior at separation distances larger than the light wavelength. However, we show that the oscillations disappear when the frequency of the random...

Université de Fribourg

Unequivocal signatures of the crossover to Anderson localization in realistic models of disordered quasi-one-dimensional materials

Lopez-Bezanilla, Alejandro ; Froufe-Pérez, Luis S. ; Roche, Stephan ; Sáenz, Juan José

In: Physical Review B, 2018, vol. 98, no. 23, p. 235423

The only unequivocal known criterion for single-parameter scaling Anderson localization relies on the knowledge of the full conductance statistics. To date, theoretical studies have been restricted to model systems with symmetric scatterers, hence lacking universality. We present an in-depth statistical study of conductance distributions P(g), in disordered ‘micrometer-long’ carbon...

Université de Fribourg

Band gap formation and Anderson localization in disordered photonic materials with structural correlations

Froufe-Pérez, Luis S. ; Engel, Michael ; Sáenz, Juan José ; Scheffold, Frank

In: Proceedings of the National Academy of Sciences, 2017, vol. 114, no. 36, p. 9570–9574

Disordered dielectric materials with structural correlations show unconventional optical behavior: They can be transparent to long-wavelength radiation, while at the same time have isotropic band gaps in another frequency range. This phenomenon raises fundamental questions concerning photon transport through disordered media. While optical transparency in these materials is robust against...

Université de Fribourg

Fluctuations of the electromagnetic local density of states as a probe for structural phase switching

Sousa, N. de ; Sáenz, Juan José ; Scheffold, Frank ; García-Martín, A. ; Froufe-Pérez, Luis S.

In: Physical Review A, 2016, vol. 94, no. 4, p. 043832

We study the statistics of the fluorescence decay rates for single quantum emitters embedded in a scattering medium undergoing a phase transition. Under certain circumstances, the structural properties of the scattering medium explore a regime in which the system dynamically switches between two different phases. While in that regime the light-scattering properties of both phases are hardly...

Université de Fribourg

Role of short-range order and hyperuniformity in the formation of band gaps in disordered photonic materials

Froufe-Pérez, Luis S. ; Engel, Michael ; Damasceno, Pablo F. ; Muller, Nicolas ; Haberko, Jakub ; Glotzer, Sharon C. ; Scheffold, Frank

In: Physical Review Letters, 2016, vol. 117, no. 5, p. 053902

We study photonic band gap formation in two-dimensional high-refractive-index disordered materials where the dielectric structure is derived from packing disks in real and reciprocal space. Numerical calculations of the photonic density of states demonstrate the presence of a band gap for all polarizations in both cases. We find that the band gap width is controlled by the increase in...

Université de Fribourg

Magneto-Optical Activity in High Index Dielectric Nanoantennas

Sousa, N. de ; Froufe-Pérez, Luis S. ; Sáenz, Juan José ; García-Martín, A.

In: Scientific Reports, 2016, vol. 6, p. 30803

The magneto-optical activity, namely the polarization conversion capabilities of high- index, non-absorbing, core-shell dielectric nanospheres is theoretically analyzed. We show that, in analogy with their plasmonic counterparts, the polarization conversion in resonant dielectric particles is linked to the amount of electromagnetic field probing the magneto-optical material in the system....

Université de Fribourg

Self-diffusion and structural properties of confined fluids in dynamic coexistence

Sousa de, N. ; Sáenz, Juan José ; Scheffold, Frank ; García-Martín, A. ; Froufe-Pérez, Luis S.

In: Journal of Physics: Condensed Matter, 2016, vol. 28, no. 13, p. 135101

Self-diffusion and radial distribution functions are studied in a strongly confined Lennard-Jones fluid. Surprisingly, in the solid–liquid phase transition region, where the system exhibits dynamic coexistence, the self-diffusion constants are shown to present up to three-fold variations from solid to liquid phases at fixed temperature, while the radial distribution function corresponding...

Université de Fribourg

High-quality photonic crystals with a nearly complete band gap obtained by direct inversion of woodpile templates with titanium dioxide

Marichy, Catherine ; Muller, Nicolas ; Froufe-Pérez, Luis S. ; Scheffold, Frank

In: Scientific Reports, 2016, vol. 6, p. 21818

Photonic crystal materials are based on a periodic modulation of the dielectric constant on length scales comparable to the wavelength of light. These materials can exhibit photonic band gaps; frequency regions for which the propagation of electromagnetic radiation is forbidden due to the depletion of the density of states. In order to exhibit a full band gap, 3D PCs must present a threshold...