5 papers · 1 filter
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…
Complex Band Structure and localisation transition for tridiagonal non-Hermitian k-Toeplitz operators with defects
Yannick De Bruijn, Erik Orvehed Hiltunen
Using the Bloch-Floquet theory, we propose an innovative technique to obtain the eigenvectors of tridiagonal k-Toeplitz operators. This method offers a more extensive and quantitat…
Complex Brillouin Zone for Localised Modes in Hermitian and Non-Hermitian Problems
Yannick De Bruijn, Erik Orvehed Hiltunen
We develop a mathematical and numerical framework for studying evanescent waves in subwavelength band gap materials. By establishing a link between the complex Brillouin zone and v…
Space-Time Wave Localisation in Systems of Subwavelength Resonators
Habib Ammari, Erik Orvehed Hiltunen, Liora Rueff
In this paper we study the dynamics of metamaterials composed of high-contrast subwavelength resonators and show the existence of localised modes in such a setting. A crucial assum…
Topological interface modes in systems with damping
Konstantinos Alexopoulos, Bryn Davies, Erik Orvehed Hiltunen
We extend the theory of topological localised interface modes to systems with damping. The spectral problem is formulated as a root-finding problem for the interface impedance func…