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Critical States Generators from Perturbed Flatbands
Sanghoon Lee, Sergej Flach, Alexei Andreanov
One-dimensional all-bands-flat lattices are networks with all bands being flat and highly degenerate. They can always be diagonalized by a finite sequence of local unitary transfor…
Critical-to-Insulator Transitions and Fractality Edges in Perturbed Flatbands
Sanghoon Lee, Alexei Andreanov, Sergej Flach
We study the effect of quasiperiodic perturbations on one-dimensional all-bands-flat lattice models. Such networks can be diagonalized by a finite sequence of local unitary transfo…
Uniform Anderson Localization in One-Dimensional Floquet Maps
Ihor Vakulchyk, Sergej Flach
We study Anderson localization in a discrete-time quantum map dynamics in one dimension with nearest-neighbor hopping strength and quasienergies located on the unit circle. We…
Metal-insulator transition in infinitesimally weakly disordered flatbands
Tilen Cadez, Yeongjun Kim, Alexei Andreanov +1
We study the effect of infinitesimal onsite disorder on d-dimensional all bands flat lattices. The lattices are generated from diagonal Hamiltonians by a sequence of (d + 1) local…
Anderson localization of excitations in disordered Gross-Pitaevskii lattices
Yagmur Kati, Mikhail V. Fistul, Alexander Yu. Cherny +1
We examine the one-dimensional Gross-Pitaevskii lattice at zero temperature in the presence of uncorrelated disorder. We obtain analytical expressions for the thermodynamic propert…
Logarithmic expansion of many-body wave packets in random potentials
Arindam Mallick, Sergej Flach
Anderson localization confines the wave function of a quantum particle in a one-dimensional random potential to a volume of the order of the localization length . Nonlinear add-…
Heat percolation in many-body flatband localizing systems
I. Vakulchyk, C. Danieli, Alexei Andreanov +1
Translationally invariant finetuned single-particle lattice Hamiltonians host flat bands only. Suitable short-range many-body interactions result in complete suppression of particl…
Multifractality of correlated two-particle bound states in quasiperiodic chains
Diana Thongjaomayum, Sergej Flach, Alexei Andreanov
We consider the quasiperiodic Aubry-André chain in the insulating regime with localised single-particle states. Adding local interaction leads to the emergence of extended correlat…
Floquet Anderson Localization of Two Interacting Discrete Time Quantum Walks
Merab Malishava, Ihor Vakulchyk, Mikhail Fistul +1
We study the interplay of two interacting discrete time quantum walks in the presence of disorder. Each walk is described by a Floquet unitary map defined on a chain of two-level s…
Taming two interacting particles with disorder
Diana Thongjaomayum, Alexei Andreanov, Thomas Engl +1
We compute the scaling properties of the localization length of two interacting particles in a one-dimensional chain with diagonal disorder, and the connectivity properties o…
Universal Nonlinear Disordered Wave Packet Subdiffusion: 12 Decades
Ihor Vakulchyk, Mikhail V. Fistul, Sergej Flach
We use a novel unitary map toolbox -- discrete time quantum walks originally designed for quantum computing -- to implement ultrafast computer simulations of extremely slow dynamic…
Fano Resonances in Flat Band Networks
Ajith Ramachandran, Carlo Danieli, Sergej Flach
Linear wave equations on Hamiltonian lattices with translational invariance are characterized by an eigenvalue band structure in reciprocal space. Flat band lattices have at least…
Anderson localization in generalized discrete time quantum walks
I. Vakulchyk, M. V. Fistul, P. Qin +1
We study Anderson localization in a generalized discrete time quantum walk - a unitary map related to a Floquet driven quantum lattice. It is controlled by a quantum coin matrix wh…
Quantum subdiffusion with two- and three-body interactions
I. I. Yusipov, T. V. Laptyeva, A. Yu. Pirova +3
We study the dynamics of a few-quantum-particle cloud in the presence of two- and three-body interactions in weakly disordered one-dimensional lattices. The interaction is dramatic…
Fractional lattice charge transport
Sergej Flach, Ramaz Khomeriki
We consider the dynamics of noninteracting electrons on a square lattice in the presence of a magnetic flux α and a dc electric field E oriented along the lattice diagonal. In gene…
Landau-Zener Bloch oscillations with perturbed flat bands
Ramaz Khomeriki, Sergej Flach
Sinusoidal Bloch oscillations appear in band structures exposed to external fields. Landau-Zener (LZ) tunneling between different bands is usually a counteracting effect limiting B…
Localization of weakly disordered flat band states
Daniel Leykam, Joshua D. Bodyfelt, Anton S. Desyatnikov +1
Certain tight binding lattices host macroscopically degenerate flat spectral bands. Their origin is rooted in local symmetries of the lattice, with destructive interference leading…
Nonlinear lattice waves in heterogeneous media
T. V. Laptyeva, M. V. Ivanchenko, S. Flach
We review recent progress in the dynamics of nonlinear lattice waves in heterogeneous media, which enforce complete wave localization in the linear wave equation limit, especially…
Flat Bands Under Correlated Perturbations
Joshua D. Bodyfelt, Daniel Leykam, Carlo Danieli +2
Flat band networks are characterized by coexistence of dispersive and flat bands. Flat bands (FB) are generated by compact localized eigenstates (CLS) with local network symmetries…
Enhancement of chaotic subdiffusion in disordered ladders with synthetic gauge fields
Xiaoquan Yu, Sergej Flach
We study spreading wave packets in a disordered nonlinear ladder with broken time-reversal symmetry induced by synthetic gauge fields. The model describes the dynamics of interacti…
Comment on "Metal-Insulator Transition in an Aperiodic Ladder Network: An Exact Result"
Sergej Flach, Carlo Danieli
Sil, Maiti, and Chakrabarti (SMC) (Phys. Rev. Lett. 101, 076803 (2008), arXiv:0801.2670) introduce an aperiodic two-leg ladder network composed of atomic sites with on-site potenti…
Flat band states: disorder and nonlinearity
Daniel Leykam, Sergej Flach, Omri Bahat-Treidel +1
We study the critical behaviour of Anderson localized modes near intersecting flat and dispersive bands in the quasi-one-dimensional diamond ladder with weak diagonal disorder .…
Decohering localized waves
K. Rayanov, G. Radons, S. Flach
In the absence of confinement localization of waves takes place due to randomness or nonlinearity and relies on their phase coherence. We quantitatively probe the sensitivity of lo…
Make Slow Fast -- how to speed up interacting disordered matter
Goran Gligorić, Kristian Rayanov, Sergej Flach
Anderson and dynamical localization have been experimentally observed with ultra-cold atomic matter. Feshbach resonances are used to efficiently control the strength of interaction…