5 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…
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…
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…