activity
20242026
collaborators

10 papers

cond-mat.mes-hall2026

Real space decay of flat band projectors from compact localized states

Yeongjun Kim, Sergej Flach, Alexei Andreanov

Flatbands (FB) with compact localized eigenstates (CLS) fall into three main categories, controlled by the algebraic properties of the CLS set: orthogonal, linearly independent, li…

cond-mat.stat-mech2026

Nematic Phase Transitions in 1D Flat Band Condensates

Yeongjun Kim, Oleg I. Utesov, Alexei Andreanov +2

We investigate the ground-state properties of one-dimensional Gross-Pitaevskii flat-band lattices which are parametrized through their compact localized state (CLS) amplitudes. We…

cond-mat.dis-nn2026

Spectral Topology and Delocalization in Disordered Hatano-Nelson Chains

Supriyo Ghosh, Sergej Flach

The unidirectional Hatano-Nelson chain serves as the fundamental non-Hermitian building block of the Su-Schrieffer-Heeger (SSH) model. We investigate its Anderson localization prop…

physics.optics2026

Synchronization-induced flat bands in driven-dissipative dimer-waveguide chains

A. N. Osipov, I. G. Savenko, Sergej Flach +1

Flat bands in driven-dissipative systems offer a route to engineer strongly localized, long-lived excitations, yet their selective population via incoherent pumping remains an open…

cond-mat.mes-hall2026

Progress on artificial flat band systems: classifying, perturbing, applying

Carlo Danieli, Sergej Flach

We highlight recent progress in the study of artificial flat band systems with a threefold focus. First, we discuss single-particle flat band physics, which has advanced through th…

cond-mat.mes-hall2025

Compact localized currents in flat bands with broken time-reversal symmetry

Rohit Kishan Ray, Carlo Danieli, Alexei Andreanov +1

We develop a systematic framework for constructing all-bands-flat (ABF) lattice Hamiltonians that explicitly break time-reversal symmetry (TRS). By threading magnetic flux through…