642 citations · 3.6k across the 24 of their papers we have counts for
25 papers
A generalized Kirchhoff's law of thermal radiation for Floquet media
Sander A. Mann, Dimitrios L. Sounas, Andrea Alù
Kirchhoff's law fundamentally relates thermal emission to absorption. For linear, static, reciprocal media, it equates the emissivity and absorptivity for each direction and freque…
First-principles analysis of energy exchange in time-varying capacitors for energy trapping applications
Kristy Hecht, David González-Ovejero, Dimitrios L. Sounas +1
Time-varying networks, consisting of lumped elements, such as resistors, capacitors, and inductors, actively modulated in time, have introduced a host of novel wave phenomena and w…
Passive Bias-Free Nonreciprocal Metasurfaces Based on Nonlinear Quasi-Bound States in the Continuum
Michele Cotrufo, Andrea Cordaro, Dimitrios L. Sounas +2
Nonreciprocal devices - in which light is transmitted with different efficiencies along opposite directions - are key technologies for modern photonic applications, yet their compa…
Static-to-dynamic field conversion with time-varying media
Mario Junior Mencagli, Dimitrios L. Sounas, Mathias Fink +1
In this Letter, we theoretically demonstrate that a uniform static electric field distribution can be partially converted to radiation fields when a portion of the medium undergoes…
Electromagnetic Isolation Induced by Time-Varying Metasurfaces: Non-Reciprocal Bragg Grating
Davide Ramaccia, Dimitrios L. Sounas, Angelica V. Marini +2
In this letter, we propose a magnet-less non-reciprocal isolating system based on time-varying metasurfaces. Two parallel time-varying metasurfaces, one for frequency up-conversion…
Phase-Induced Frequency Conversion and Doppler Effect with Time-Modulated Metasurfaces
Davide Ramaccia, Dimitrios L. Sounas, Andrea Alu' +2
Metasurfaces consisting of electrically thin and densely packed planar arrays of subwavelength elements enable an unprecedented control of the impinging electromagnetic fields. Spa…
Can a nonradiating mode be externally excited? Nonscattering states vs. embedded eigenstates
Francesco Monticone, Dimitrios Sounas, Alex Krasnok +1
In this Letter, we discuss the general problem of exciting radiationless field distributions in open cavities, with the goal of clarifying recent findings on this topic. We point o…
Highly-Linear Magnet-Free Microelectromechanical Circulators
Yao Yu, Giuseppe Michetti, Ahmed Kord +6
This paper reports the first demonstration of a magnet-free, high performance microelectromechanical system (MEMS) based circulator. An innovative circuit based on the commutation…
Radio Frequency Magnet-free Circulators Based on Spatiotemporal Modulation of Surface Acoustic Wave Filters
Yao Yu, Giuseppe Michetti, Michele Pirro +6
In this paper, a new generation of magnet-free circulators with high performance is proposed. Circulators are crucial devices in modern communication systems due to their ability t…
High-index dielectric metasurfaces performing mathematical operations
Andrea Cordaro, Hoyeong Kwon, Dimitrios Sounas +3
Image processing and edge detection are at the core of several newly emerging technologies, such as augmented reality, autonomous driving and more generally object recognition. Ima…
CMOS Integrated Magnetless Circulators Based on Spatiotemporal Modulation Angular-Momentum Biasing
Ahmed Kord, Mykhailo Tymchenko, Dimitrios Sounas +2
In this paper, we introduce the first integrated circuit (IC) implementation of spatiotemporally modulated angular-momentum (STM-AM) biased magnetless circulators. The design is ba…
Non-Reciprocal Willis Coupling in Zero-Index Moving Media
Li Quan, Dimitrios L. Sounas, Andrea Alu
Mechanical motion can break the symmetry in which sound travels in a medium, but significant non-reciprocity is typically achieved only for very large motion speeds. Here we combin…
What is Nonreciprocity?
Christophe Caloz, Andrea Alù, Sergei Tretyakov +3
This paper aims at providing a global perspective on electromagnetic nonreciprocity and clarifying confusions that arose in the recent developments of the field. It provides a gene…
Broadband Cyclic-Symmetric Magnet-less Circulators and Theoretical Bounds on their Bandwidth
Ahmed Kord, Dimitrios L. Sounas, Zhicheng Xiao +1
In this paper, we explore theoretically and experimentally broadband spatiotemporally modulated (STM) magnet-less circulators realized by combining three-port non-reciprocal juncti…
Nonreciprocal Cavities and the Time-Bandwidth Limit
Sander A. Mann, Dimitrios L. Sounas, Andrea Alù
The time-bandwidth limit inherently relates the lifetime of a resonance and its spectral bandwidth, with direct implications on the maximum storage time of a pulse versus its frequ…
What is Nonreciprocity? Part II
Christophe Caloz, Andrea Alù, Sergei Tretyakov +3
This paper is the second part of a two-part paper on \emph{Electromagnetic (EM) Nonreciprocity (NR)}. Part~I has defined NR, pointed out that linear NR is a stronger form of NR tha…
Non-reciprocal Components Based on Switched Transmission Lines
Aravind Nagulu, Tolga Dinc, Zhicheng Xiao +4
Non-reciprocal components, such as isolators and circulators, are critical to wireless communication and radar applications. Traditionally, non-reciprocal components have been impl…
Maximum Willis Coupling in Acoustic Scatterers
Li Quan, Younes Ra'di, Dimitrios Sounas +1
Willis coupling in acoustic materials defines the cross-coupling between strain and velocity, analogous to bianisotropic phenomena in electromagnetics. While these effects have bee…
Non-reciprocal Optical Mirrors Based on Spatio-Temporal Modulation
Romain Fleury, Dimitrios L. Sounas, Andrea Alu
The recent surge of interest in temporal modulation schemes to induce magnet-free non-reciprocity has inspired several exciting opportunities for photonic technology. Here, we inve…
Pseudo-Linear Time-Invariant Magnetless Circulators Based on Differential Spatiotemporal Modulation of Resonant Junctions
Ahmed Kord, Dimitrios L. Sounas, Andrea Alù
In this paper, we present voltage- and current-mode differential magnetless non-reciprocal devices obtained by pairing two single-ended (SE) circulators, each consisting of three f…
Magnetless Circulators Based on Spatiotemporal Modulation of Bandstop Filters in a Delta Topology
Ahmed Kord, Dimitrios L. Sounas, Andrea Alù
In this paper, we discuss the design rationale and guidelines to build magnet-less circulators based on spatio-temporal modulation of resonant junctions consisting of first-order b…
Meta-Gratings: Beyond the Limits of Graded Metasurfaces for Wavefront Control
Younes Ra'di, Dimitrios L. Sounas, Andrea Alu
Graded metasurfaces exploit the local momentum imparted by an impedance gradient to transform the impinging wavefront. This approach suffers from fundamental limits on the overall…
Static non-reciprocity in mechanical metamaterials
Corentin Coulais, Dimitrios Sounas, Andrea Alù
Reciprocity is a fundamental principle governing various physical systems, which ensures that the transfer function between any two points in space is identical, regardless of geom…
Space-time gradient metasurfaces
Y. Hadad, D. L. Sounas, A. Alu
Metasurfaces characterized by a transverse gradient of local impedance have recently opened exciting directions for light manipulation at the nanoscale. Here we add a temporal grad…