Stotland, Alexander, Kottos, Tsampikos, Cohen, Doron
Semi-linear response theory determines the absorption coefficient of a driven system using a resistor network calculation: Each unperturbed energy level of a particle in a vibrating trap, or of an...
Exponentially Fragile PT-Symmetry in Lattices with Localized Eigenmodes (2009)
Bendix, Oliver, Fleischmann, Ragnar, Kottos, Tsampikos, Shapiro, Boris
We study the effect of localized modes in lattices of size N with parity-time (PT) symmetry. Such modes are arranged in pairs of quasi-degenerate levels with splitting delta exp{-N/xi}, where \xi is...
Quantum decay into a non-flat continuum (2009)
Aisenberg, James, Sela, Itamar, Kottos, Tsampikos, Cohen, Doron, Elgart, Alex
We study the decay of a prepared state into non-flat continuum. We find that the survival probability $P(t)$ might exhibit either stretched-exponential or power-law decay, depending on non-universal...
Probing Localization in Absorbing Systems via Loschmidt Echos (2009)
Bodyfelt, Joshua D., Zheng, Mei C., Kottos, Tsampikos, Kuhl, Ulrich, Stöckmann, Hans-Jürgen
We measure Anderson localization in quasi-one-dimensional waveguides in the presence of absorption by analyzing the echo dynamics due to small perturbations. We specifically show that the inverse...
Wavepacket dynamics in energy space of a chaotic trimeric Bose-Hubbard system (2009)
Hiller, Moritz, Kottos, Tsampikos, Geisel, Theo
We study the energy redistribution of interacting bosons in a ring-shaped quantum trimer as the coupling strength between neighboring sites of the corresponding Bose-Hubbard Hamiltonian undergoes a...
Occupation Statistics of a BEC for a Driven Landau-Zener Crossing (2009)
Smith-Mannschott, Katrina, Chuchem, Maya, Hiller, Moritz, Kottos, Tsampikos, Cohen, Doron
We consider an atomic Bose-Einstein condensate (BEC) loaded in a biased double-well trap with tunneling rate $K$ and inter-atomic interaction $U$. The BEC is prepared such that all $N$ atoms are in...
Loschmidt Gap in Dynamical Systems with Critical Chaos (2008)
West, Carl T., Prosen, Tomaz, Kottos, Tsampikos
We study the Loschmidt echo for a class of dynamical systems showing critical chaos. Using a kicked rotor with singular potential as a prototype model, we found that the classical echo shows a gap...
Controlled quantum stirring of Bose-Einstein condensates (2008)
Hiller, Moritz, Kottos, Tsampikos, Cohen, Doron
By cyclic adiabatic change of two control parameters of an optical trap one can induce a circulating current of condensed bosons. The amount of particles that are transported per period depends on...
INSTITUTE OF PHYSICS PUBLISHING JOURNAL OF PHYSICS A: MATHEMATICAL AND GENERAL (2008)
Statistics of resonances and delay times in random
Stotland, Alexander, Budoyo, Rangga, Peer, Tal, Kottos, Tsampikos, Cohen, Doron
The calculation of the conductance of disordered rings requires a theory that goes beyond the Kubo-Drude formulation. Assuming "mesoscopic" circumstances the analysis of the electro-driven...
Tsampikos Kottos, Uzy Smilansky, Joaquim Fortuny
In this paper we analyze a recent experiment conducted in an anechoic chamber, where the scattering of microwaves from an array of metallic cylinders was measured. This is a system which displays...
Control of atomic currents using a quantum stirring device (2007)
Hiller, Moritz, Kottos, Tsampikos, Cohen, Doron
We propose a BEC stirring device which can be regarded as the incorporation of a quantum pump into a closed circuit: it produces a DC circulating current in response to a cyclic adiabatic change of...
Scaling properties of delay times in one-dimensional random media (2007)
Bodyfelt, Joshua D., Mendez-Bermudez, J. A., Chabanov, Andrey, Kottos, Tsampikos
The scaling properties of the inverse moments of Wigner delay times are investigated in finite one-dimensional (1D) random media with one channel attached to the boundary of the sample. We find that...
Wavepacket dynamics of the nonlinear Harper model (2007)
Ng, Gim Seng, Kottos, Tsampikos
The destruction of anomalous diffusion of the Harper model at criticality, due to weak nonlinearity $\chi$, is analyzed. It is shown that the second moment grows subdiffusively as $ \sim t^{\alpha}$...
Complexity in parametric Bose-Hubbard Hamiltonians and structural analysis of eigenstates (2006)
Hiller, Moritz, Kottos, Tsampikos, Geisel, T.
We consider a family of chaotic Bose-Hubbard Hamiltonians (BHH) parameterized by the coupling strength $k$ between neighboring sites. As $k$ increases the eigenstates undergo changes, reflected in...
Ng, Gim Seng, Bodyfelt, Joshua, Kottos, Tsampikos
Using a Wigner Lorentzian Random Matrix ensemble, we study the fidelity, $F(t)$, of systems at the Anderson metal-insulator transition, subject to small perturbations that preserve the criticality....
Resonance width distribution for high-dimensional random media (2005)
Weiss, Matthias, Mendez-Bermudez, J. A., Kottos, Tsampikos
We study the distribution of resonance widths P(G) for three-dimensional (3D) random scattering media and analyze how it changes as a function of the randomness strength. We are able to identify in...
Parametric invariant Random Matrix Model and the emergence of multifractality (2005)
Mendez-Bermudez, J. A., Kottos, Tsampikos, Cohen, Doron
We propose a random matrix modeling for the parametric evolution of eigenstates. The model is inspired by a large class of quantized chaotic systems. Its unique feature is having parametric...
Statistics of Resonances and Delay Times in Random Media: Beyond Random Matrix Theory (2005)
We review recent developments on quantum scattering from mesoscopic systems. Various spatial geometries whose closed analogs shows diffusive, localized or critical behavior are considered. These are...
We review quantum chaos on graphs. We construct a unitary operator which represents the quantum evolution on the graph and study its spectral and wavefunction statistics. This operator is the...
Rate of energy absorption by a closed ballistic ring (2005)
Cohen, Doron, Kottos, Tsampikos, Schanz, Holger
We make a distinction between the spectroscopic and the mesoscopic conductance of closed systems. We show that the latter is not simply related to the Landauer conductance of the corresponding open...
Mendez-Bermudez, J. A., Kottos, Tsampikos, Cohen, Doron
Considering a quantized chaotic system, we analyze the evolution of its eigenstates as a result of varying a control parameter. As the induced perturbation becomes larger, there is a crossover from a...
Quantum pumping: The charge transported due to a translation of a scatterer (2004)
Cohen, Doron, Kottos, Tsampikos, Schanz, Holger
The amount of charge which is pushed by a moving scatterer is $dQ = -G dX$, where $dX$ is the displacement of the scatterer. The question is what is $G$. Does it depend on the transmission $g_0$ of...
Current relaxation in nonlinear random media (2004)
Kottos, Tsampikos, Weiss, Matthias
We study the current relaxation of a wave packet in a nonlinear random sample coupled to the continuum and show that the survival probability decays as $P(t) \sim 1/t^{\alpha}$. For intermediate...
Quantum decay of an open chaotic system: a semiclassical approach (2004)
Puhlmann, Mathias, Schanz, Holger, Kottos, Tsampikos, Geisel, Theo
We study the quantum probability to survive in an open chaotic system in the framework of the van Vleck-Gutzwiller propagator and present the first such calculation that accounts for quantum...
Probing the eigenfunction fractality with a stop watch (2004)
Mendez-Bermudez, J. A., Kottos, Tsampikos
We study numerically the distribution of scattering phases ${\cal P}(\Phi)$ and of Wigner delay times ${\cal P}(\tau_W)$ for the power-law banded random matrix (PBRM) model at criticality with one...
Superconductor-proximity effect in hybrid structures: Fractality versus Chaos (2003)
Ossipov, A., Kottos, Tsampikos
We study the proximity effect of a superconductor to a normal system with fractal spectrum. We find that there is no gap in the excitation spectrum, even in the case where the underlying classical...
Quantum Reversibility: Is there an Echo? (2003)
Hiller, Moritz, Kottos, Tsampikos, Cohen, Doron, Geisel, Theo
We study the possibility to undo the quantum mechanical evolution in a time reversal experiment. The naive expectation, as reflected in the common terminology ("Loschmidt echo"), is that maximum...
Signatures of Classical Diffusion in Quantum Fluctuations of 2D Chaotic Systems (2003)
Kottos, Tsampikos, Ossipov, Alexander, Geisel, Theo
We consider a two-dimensional (2D) generalization of the standard kicked-rotor (KR) and show that it is an excellent model for the study of 2D quantum systems with underlying diffusive classical...
Scars on quantum networks ignore the Lyapunov exponent (2003)
Schanz, Holger, Kottos, Tsampikos
We show that enhanced wavefunction localization due to the presence of short unstable orbits and strong scarring can rely on completely different mechanisms. Specifically we find that in quantum...
Quantum Dissipation due to the Interaction with Chaos (2003)
Cohen, Doron, Kottos, Tsampikos
We discuss the possibility of having "quantum dissipation" due to the interaction with chaotic degrees of freedom. We define the conditions that should be satisfied in order to have a dissipative...
Statistical properties of resonance widths for open Quantum Graphs (2003)
Kottos, Tsampikos, Schanz, Holger
We connect quantum compact graphs with infinite leads, and turn them into scattering systems. We derive an exact expression for the scattering matrix, and explain how it is related to the spectrum of...
Fingerprints of classical diffusion in open 2D mesoscopic systems in the metallic regime (2002)
Ossipov, A., Kottos, Tsampikos, Geisel, T.
We investigate the distribution of the resonance widths ${\cal P}(\Gamma)$ and Wigner delay times ${\cal P}(\tau_W)$ for scattering from two-dimensional systems in the diffusive regime. We obtain the...
Quantum Graphs: A simple model for Chaotic Scattering (2002)
Kottos, Tsampikos, Smilansky, Uzy
We connect quantum graphs with infinite leads, and turn them to scattering systems. We show that they display all the features which characterize quantum scattering systems with an underlying...
Non-perturbative response: chaos versus disorder (2002)
Cohen, Doron, Kottos, Tsampikos
Quantized chaotic systems are generically characterized by two energy scales: the mean level spacing $\Delta$, and the bandwidth $\Delta_b\propto\hbar$. This implies that with respect to driving such...
Signatures of Prelocalized States in Classically Chaotic Systems (2002)
Ossipov, A., Kottos, Tsampikos, Geisel, T.
We investigate the statistics of eigenfunction intensities ${\cal P}(|\psi|^2)$ in dynamical systems with classical chaotic diffusion. Our results contradict some recent theoretical considerations...
Quantum Irreversibility of Energy Spreading (2002)
Kottos, Tsampikos, Cohen, Doron
The analysis of dissipation and dephasing in driven mesoscopic devices requires a distinction between two notions of quantum irreversibility. One ("Loschmidt echo") is related to "time reversal",...
Chaotic Scattering of Microwaves (2001)
Kottos, Tsampikos, Smilansky, Uzy, Fortuny, Joaquim, Nesti, Giuseppe
In this paper we analyze a recent experiment conducted in an anechoic chamber, where the scattering of microwaves from an array of metallic cylinders was measured. This is a system which displays...
Statistics of resonances and delay times: A criterion for Metal-Insulator transitions (2001)
Kottos, Tsampikos, Weiss, Matthias
We study the distributions of the normalized resonance widths ${\cal P} ({\tilde \Gamma})$ and delay times ${\cal P} ({\tilde \tau})$ for $3$D disordered tight-binding systems at the metal-insulator...
Taming chaos by impurities in two-dimensional oscillator arrays (2001)
Weiss, M., Kottos, Tsampikos, Geisel, T.
The effect of impurities in a two-dimensional lattice of coupled nonlinear chaotic oscillators and their ability to control the dynamical behavior of the system are studied. We show that a single...
Failure of random matrix theory to correctly describe quantum dynamics (2001)
Kottos, Tsampikos, Cohen, Doron
Consider a classically chaotic system which is described by a Hamiltonian H_0. At t=0 the Hamiltonian undergoes a sudden-change H_0 -> H. We consider the quantum-mechanical spreading of the evolving...
Quantum mechanical relaxation of open quasiperiodic systems (2001)
Ossipov, A., Weiss, M., Kottos, Tsampikos, Geisel, T.
We study the time evolution of the survival probability $P(t)$ in open one-dimensional quasiperiodic tight-binding samples of size $L$, at critical conditions. We show that it decays algebraically as...
Effect of resonances on the transport properties of two-dimensional disordered systems (2000)
Elattari, Brahim, Kottos, Tsampikos
We study both analytically and numerically how the electronic structure and the transport properties of a two-dimensional disordered system are modified in the presence of resonances. The energy...
Statistics of resonances and of delay times in quasiperiodic Schr"odinger equations (2000)
Steinbach, F., Ossipov, A., Kottos, Tsampikos, Geisel, T.
We study the statistical distributions of the resonance widths ${\cal P} (\Gamma)$, and of delay times ${\cal P} (\tau)$ in one dimensional quasi-periodic tight-binding systems with one open channel....
Spreading and localization of wavepackets in disordered wires in a magnetic field (2000)
Weiss, Matthias, Kottos, Tsampikos, Geisel, Theo
We study the diffusive and localization properties of wavepackets in disordered wires in a magnetic field. In contrast to a recent supersymmetry approach our numerical results show that the decay...
Weiss, Matthias, Kottos, Tsampikos, Geisel, Theo
We investigate the scaling properties of eigenstates of a one-dimensional (1D) Anderson model in the presence of a constant electric field. The states show a transition from exponential to factorial...
Quantum-Mechanical Non-Perturbative Response of Driven Chaotic Mesoscopic Systems (2000)
Cohen, Doron, Kottos, Tsampikos
Consider a time-dependent Hamiltonian $H(Q,P;x(t))$ with periodic driving $x(t)=A\sin(\Omega t)$. It is assumed that the classical dynamics is chaotic, and that its power-spectrum extends over some...
Quantum Graphs: A model for Quantum Chaos (2000)
Kottos, Tsampikos, Schanz, Holger
We study the statistical properties of the scattering matrix associated with generic quantum graphs. The scattering matrix is the quantum analogue of the classical evolution operator on the graph....
Cohen, Doron, Kottos, Tsampikos
We study a classically chaotic system which is described by a Hamiltonian $H(Q,P;x)$ where $(Q,P)$ are the canonical coordinates of a particle in a 2D well, and $x$ is a parameter. By changing $x$ we...
Ossipov, A., Kottos, Tsampikos, Geisel, T.
We study the distribution of phases and of Wigner delay times for a one-dimensional Anderson model with one open channel. Our approach, based on classical Hamiltonian maps, allows us an analytical...
Wavepacket dynamics in energy space, RMT and quantum-classical correspondence (1999)
Cohen, Doron, Izrailev, Felix M., Kottos, Tsampikos
We apply random-matrix-theory (RMT) to the analysis of evolution of wavepackets in energy space. We study the crossover from ballistic behavior to saturation, the possibility of having an...
Chaotic Scattering on Graphs (1999)
Kottos, Tsampikos, Smilansky, U.
Quantized, compact graphs were shown to be excellent paradigms for quantum chaos in bounded systems. Connecting them with leads to infinity we show that they display all the features which...
Periodic orbit theory and spectral statistics for quantum graphs (1999)
Tsampikos Kottos, Uzy Smilansky
We quantize graphs (networks) which consist of a nite number of bonds and vertices. We show that the spectral statistics of fully connected graphs is well reproduced by random matrix theory. We also...
Quantum Graphs: A model for Quantum Chaos (1999)
Tsampikos Kottos, Holger Schanz
We study the statistical properties of the scattering matrix associated with generic quantum graphs. The scattering matrix is the quantum analogue of the classical evolution operator on the graph....
Self-organization of coupled nonlinear oscillators (1998)
Gavrielides, Athanasios, Kottos, Tsampikos, Kovanis, Vassilios, Tsironis, George
This article may be accessed on the publisher's website (additional fees may apply) at: http://epljournal.edpsciences.org/index.php?option=article&access=doi&doi=10.1209/epl/i1998-00509-0
Periodic Orbit Theory and Spectral Statistics for Quantum Graphs (1998)
Kottos, Tsampikos, Smilansky, Uzy
We quantize graphs (networks) which consist of a finite number of bonds and vertices. We show that the spectral statistics of fully connected graphs is well reproduced by random matrix theory. We...
Spatiotemporal organization of coupled nonlinear pendula through impurities (1998)
Gavrielides, Athanasios, Kottos, Tsampikos, Kovanis, Vassilios, Tsironis, George
Copyright 1998 American Physical Society. All Rights Reserved. This article may also be accessed on the journal's website (additional fees may apply) at:...