249 citations · 1.1k across the 22 of their papers we have counts for
23 papers
Nonreciprocal plasmonic response of drift-biased two-dimensional metals
Gonzalo Álvarez-Pérez, Joel D. Cox
We develop a nonlocal electrodynamic framework for drift-biased two-dimensional electron gases (2DEGs) with Dirac (linear) and parabolic (quadratic) dispersions, deriving closed-fo…
Nonlocal-nonlinear phonon polaritons
Gonzalo Álvarez-Pérez, Line Jelver, Alexander Paarmann +1
When light is confined to deeply subwavelength volumes, optical responses can become nonlocal. Yet how nonlocality reshapes nonlinear light-matter interactions remains largely unex…
In-plane vector-field imaging of propagating surface phonon polaritons
Richarda Niemann, Dorothée S. Mader, Gonzalo Alvarez-Pérez +9
Polariton interferometry through optical near-field microscopy has become a powerful tool in nanophotonics, enabling direct spatial access to the propagation characteristics of str…
Uncovering the properties of homo-epitaxial GaN devices through cross-sectional infrared nanoscopy
Hossein Zandipour, Felix Kaps, Robin Buschbeck +19
Validating material performance in electrical devices is crucial to product development. For Gallium Nitride (GaN) devices, evaluating material factors such as defects, dopant conc…
Misalignment between the Directions of Propagation and Decay of Nanoscale-confined Polaritons
Kirill V. Voronin, Gonzalo Álvarez-Pérez, Aitana Tarazaga Martín-Luengo +2
Anisotropic van der Waals crystals have gained significant attention in nanooptics and optoelectronics due to their unconventional optical properties, including anomalous reflectio…
Spectral tuning of hyperbolic shear polaritons in monoclinic gallium oxide via isotopic substitution
Giulia Carini, Mohit Pradhan, Elena Gelzinyte +26
Hyperbolic phonon polaritons - hybridized modes arising from the ultrastrong coupling of infrared light to strongly anisotropic lattice vibrations in uniaxial or biaxial polar crys…
Roadmap for Photonics with 2D Materials
F. Javier García de Abajo, D. N. Basov, Frank H. L. Koppens +145
Triggered by the development of exfoliation and the identification of a wide range of extraordinary physical properties in self-standing films consisting of one or few atomic layer…
Broad Spectral Tuning of Ultra-Low Loss Polaritons in a van der Waals Crystal by Intercalation
Javier Taboada-Gutiérrez, Gonzalo Álvarez-Pérez, Jiahua Duan +17
Phonon polaritons (PhPs) -- light coupled to lattice vibrations -- in polar van der Waals (vdW) crystals are promising candidates for controlling the flow of energy at the nanoscal…
Unveiling the Mechanism of Phonon-Polariton Damping in α-MoO_3
Javier Taboada-Gutiérrez, Yixi Zhou, Ana I. F. Tresguerres-Mata +14
Phonon polaritons (PhPs) (light coupled to lattice vibrations) in the highly anisotropic polar layered material molybdenum trioxide (α-MoO_3) are currently the focus of intense res…
Low-power threshold optical bistability enabled by hydrodynamic Kerr nonlinearity of free-carriers in heavily doped semiconductors
Huatian Hu, Gonzalo Álvarez-Pérez, Tadele Orbula Otomalo +1
We demonstrate nanoscale optical bistability at an exceptionally low power threshold of 1 mW by leveraging Kerr-type hydrodynamic nonlinearities due to the heavily doped semiconduc…
Unidirectional Ray Polaritons in Twisted Asymmetric Stacks
J. Álvarez-Cuervo, M. Obst, S. Dixit +25
The vast repository of van der Waals (vdW) materials supporting polaritons offers numerous possibilities to tailor electromagnetic waves at the nanoscale. The development of twisto…
Extreme light confinement and control in low-symmetry phonon-polaritonic crystals
Emanuele Galiffi, Giulia Carini, Xiang Ni +9
Polaritons are a hybrid class of quasiparticles originating from the strong and resonant coupling between light and matter excitations. Recent years have witnessed a surge of inter…
Multiple and spectrally robust photonic magic angles in reconfigurable α-MoO3 trilayers
J. Duan, G. Álvarez-Pérez, C. Lanza +8
The assembling of twisted stacks of van der Waals (vdW) materials had led to the discovery of a profusion of remarkable physical phenomena in recent years, as it provides a means t…
Fundamentals of polaritons in strongly anisotropic thin crystal layers
Kirill V. Voronin, Gonzalo Álvarez-Pérez, Christian Lanza +2
Polaritons in strongly anisotropic thin layers have recently captured the attention in nanophotonics because of their directional propagation at the nanoscale, which offers unique…
Terahertz Twistoptics -- engineering canalized phonon polaritons
Maximilian Obst, Tobias Nörenberg, Gonzalo Álvarez-Pérez +11
The terahertz (THz) frequency range is key to study collective excitations in many crystals and organic molecules. However, due to the large wavelength of THz radiation, the local…
Negative reflection of polaritons at the nanoscale in a low-loss natural medium
Gonzalo Alvarez-Perez, Jiahua Duan, Javier Taboada-Gutierrez +10
Negative reflection occurs when light is reflected towards the same side of the normal to the boundary from which it is incident. This exotic optical phenomenon, which provides a n…
Germanium monosulfide as a natural platform for highly anisotropic THz polaritons
Tobias Nörenberg, Gonzalo Álvarez-Pérez, Maximilian Obst +8
Terahertz (THz) electromagnetic radiation is key to optically access collective excitations such as magnons (spins), plasmons (electrons), or phonons (atomic vibrations), thus brid…
Active tuning of highly anisotropic phonon polaritons in van der Waals crystal slabs by gated graphene
Gonzalo Álvarez-Pérez, Arturo González-Morán, Nathaniel Capote-Robayna +5
Phonon polaritons (PhPs) -- lattice vibrations coupled to electromagnetic fields -- in highly anisotropic media display a plethora of intriguing optical phenomena (including ray-li…
Focusing of in-plane hyperbolic polaritons in van der Waals crystals with tailored infrared nanoantennas
Javier Martín-Sánchez, Jiahua Duan, Javier Taboada-Gutiérrez +9
Phonon polaritons (PhPs),light coupled to lattice vibrations,with in-plane hyperbolic dispersion exhibit ray-like propagation with large wavevectors and enhanced density of optical…
Twisted Nano-optics: Manipulating Light at the Nanoscale with Twisted Phonon Polaritonic Slabs
Jiahua Duan, Nathaniel Capote-Robayna, Javier Taboada-Gutierrez +5
Recent discoveries have shown that when two layers of van der Waals (vdW) materials are superimposed with a relative twist angle between their respective in-plane principal axes, t…
Infrared permittivity of the biaxial van der Waals semiconductor -MoO from near- and far-field correlative studies
Gonzalo Álvarez-Pérez, Thomas G. Folland, Ion Errea +13
The biaxial van der Waals semiconductor -phase molybdenum trioxide (-MoO) has recently received significant attention due to its ability to support highly anisotropic pho…
A goodness-of-fit test for the functional linear model with functional response
Eduardo García-Portugués, Javier Álvarez-Liébana, Gonzalo Álvarez-Pérez +1
The Functional Linear Model with Functional Response (FLMFR) is one of the most fundamental models to assess the relation between two functional random variables. In this paper, we…
Analytical approximations for the dispersion of electromagnetic modes in slabs of biaxial crystals
Gonzalo Álvarez-Pérez, Kirill V. Voronin, Valentyn S. Volkov +2
Anisotropic crystals have recently attracted considerable attention because of their ability to support polaritons with a variety of unique properties, such as hyperbolic dispersio…