12 papers
Topologically protected interface modes in multi-band damped lattice models
Yannick de Bruijn, Erik Orvehed Hiltunen
Tridiagonal -Toeplitz operators provide a natural framework for modelling one-dimensional -periodic lattice systems. A fundamental connection is obtained between Coburn's lem…
Non-Hermitian Fabry-Pérot Resonances
Habib Ammari, Erik Orvehed Hiltunen, Bowen Li +4
We characterise non-Hermitian Fabry-Pérot resonances in high-contrast resonator systems and study the properties of their associated resonant modes from continuous differential mo…
Mathematical Foundation for the Generalised Brillouin zone of m-banded Toeplitz operators
Yannick de Bruijn, Erik Orvehed Hiltunen
We show that the spectrum of the open-boundary limit of banded Toeplitz matrices is real whenever the associated symbol function is real-valued along a closed polar curve. Building…
A Tight-binding Approach for Computing Subwavelength Guided Modes in Crystals with Line Defects
Habib Ammari, Erik Orvehed Hiltunen, Ping Liu +2
In this paper, we develop an accurate and efficient framework for computing subwavelength guided modes in high-contrast periodic media with line defects, based on a tight-binding a…
Spectra and pseudospectra of non-Hermitian Toeplitz operators: Eigenvector decay transitions in banded and dense matrices
Yannick de Bruijn, Bryn Davies, Sacha Dupuy +1
Using a generalised Floquet-Bloch theory, we present a mathematical method to construct eigenvectors for non-Hermitian Toeplitz operators. We extend the method to both banded Toepl…
Optical theorem and generalized energy conservation for scattering of time-modulated waves
Erik Orvehed Hiltunen, John C. Schotland
We introduce and study a generalized energy conservation relation for scattering of time-modulated waves, where conventional energy conservation does not hold. Based on this relati…