J. Luczka

Publications (33)23.5 Total impact

• Article: Absolute negative mobility induced by white Poissonian noise

  J. Spiechowicz, J. Luczka, P. Hanggi
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  ABSTRACT: We research the transport properties of inertial Brownian particles which move in a symmetric periodic potential and are subjected to both a symmetric, unbiased time-periodic external force and biased Poissonian white shot noise (of non-zero average F) being composed of a random sequence of delta-shaped pulses with random amplitudes. Upon varying the parameters of white shot-noise one conveniently can manipulate the transport direction and the overall nonlinear response behavior. Within tailored parameter regimes, we find that the response is opposite to the applied average bias F of such white shot noise. This very transport characteristics thus mimics a nonlinear Absolute Negative Mobility (ANM) regime. Moreover, such white shot noise driven ANM is robust with respect to statistics of the shot noise spikes. Our findings can be checked and corroborated experimentally by use of a setup that consists of a single resistively and capacitively shunted Josephson junction device.
  11/2012;
• Article: Squeezing of magnetic flux in nanorings.

  J Dajka, A Ptok, J Luczka
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  ABSTRACT: We study superconducting and non-superconducting nanorings and look for non-classical features of magnetic flux passing through nanorings. We show that the magnetic flux can exhibit purely quantum properties in some peculiar states with quadrature squeezing. We identify a subset of Gazeau-Klauder states in which the magnetic flux can be squeezed and, within tailored parameter regimes, quantum fluctuations of the magnetic flux can be maximally reduced.
  Journal of Physics Condensed Matter 11/2012; 24(49):495701. · 2.55 Impact Factor
• Article: Negativity and quantum discord in Davies environments

  J. Dajka, M. Mierzejewski, J. Luczka, R. Blattmann, P. Hanggi
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  ABSTRACT: We investigate the time evolution of negativity and quantum discord for a pair of non-interacting qubits with one being weakly coupled to a decohering Davies--type Markovian environment. At initial time of preparation, the qubits are prepared in one of the maximally entangled pure Bell states. In the limiting case of pure decoherence (i.e. pure dephasing), both, the quantum discord and negativity decay to zero in the long time limit. In presence of a manifest dissipative dynamics, the entanglement negativity undergoes a sudden death at finite time while the quantum discord relaxes continuously to zero with increasing time. We find that in dephasing environments the decay of the negativity is more propitious with increasing time; in contrast, the evolving decay of the quantum discord proceeds weaker for dissipative environments. Particularly, the slowest decay of the quantum discord emerges when the energy relaxation time matches the dephasing time.
  09/2012;
• Source

  Available from: Lukasz Machura

  Article: Directed transport in coupled noisy Josephson junctions controlled via ac signals

  L. Machura, J. Spiechowicz, J. Luczka
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  ABSTRACT: Transport properties of two coupled Josephson junctions driven by ac currents and thermal fluctuations are studied with the purpose of determining dc voltage characteristics. It is a physical realization of directed transport induced by a non-biased zero averaged external signal. The ac current is applied either to (A) only one junction as a biharmonic current or (B) is split into two simple harmonic components and separately applied to respective junctions. We identify regimes where junctions can operate with the same as well as opposite signs of voltages. A general observation is that in the same parameters regimes, the scenario (B) is more efficient in the sense that the induced dc voltages take greater values.
  03/2012;
• Source

  Available from: Lukasz Machura

  Article: Control of transport characteristics in two coupled Josephson junctions

  J. Spiechowicz, L. Machura, M. Kostur, J. Luczka
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  ABSTRACT: We report on a theoretical study of transport properties of two coupled Josephson junctions and compare two scenarios for controlling the current-voltage characteristics when the system is driven by an external biased DC current and unbiased AC current consisting of one harmonic. In the first scenario, only one junction is subjected to both DC and AC currents. In the second scenario the signal is split -- one junction is subjected to the DC current while the other is subjected to the AC current. We study DC voltages across both junctions and find diversity of anomalous transport regimes for the first and second driving scenarios.
  02/2012;
• Article: Current-flux characteristics in mesoscopic non-superconducting rings.

  L Machura, Sz Rogozinski, J Luczka
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  ABSTRACT: We propose four different mechanisms responsible for the paramagnetic or diamagnetic persistent currents in normal metal rings and determine the circumstances for changes of the current from paramagnetic to diamagnetic and vice versa. This might qualitatively reproduce the experimental results of Bluhm et al (2009 Phys. Rev. Lett. 102 136802).
  Journal of Physics Condensed Matter 10/2010; 22(42):422201. · 2.55 Impact Factor
• Source

  Available from: ArXiv

  Article: Distance growth of quantum states due to initial system--environment correlations

  J. Dajka, J. Luczka
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  ABSTRACT: Intriguing features of the distance between two arbitrary states of an open quantum system are identified that are induced by initial system-environment correlations. As an example, we analyze a qubit dephasingly coupled to a bosonic environment. Within tailored parameter regimes, initial correlations are shown to substantially increase a distance between two qubit states evolving to long-time limit states according to exact non-Markovian dynamics. It exemplifies the breakdown of the distance contractivity of the reduced dynamics. Comment: 4 pages, 3 figures
  05/2010;
• Source

  Available from: ArXiv

  Article: Geometric phase as a determinant of a qubit--environment coupling

  J. Dajka, J. Luczka, P. Hanggi
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  ABSTRACT: We investigate the qubit geometric phase and its properties in dependence on the mechanism for decoherence of a qubit weakly coupled to its environment. We consider two sources of decoherence: dephasing coupling (without exchange of energy with environment) and dissipative coupling (with exchange of energy). Reduced dynamics of the qubit is studied in terms of the rigorous Davies Markovian quantum master equation, both at zero and non--zero temperature. For pure dephasing coupling, the geometric phase varies monotonically with respect to the polar angle (in the Bloch sphere representation) parameterizing an initial state of the qubit. Moreover, it is antisymmetric about some points on the geometric phase-polar angle plane. This is in distinct contrast to the case of dissipative coupling for which the variation of the geometric phase with respect to the polar angle typically is non-monotonic, displaying local extrema and is not antisymmetric. Sensitivity of the geometric phase to details of the decoherence source can make it a tool for testing the nature of the qubit--environment interaction.
  04/2010;
• Source

  Available from: Marcin Kostur

  Article: Negative mobility induced by colored thermal fluctuations.

  M Kostur, J Luczka, P Hänggi
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  ABSTRACT: Anomalous transport of non-Markovian thermal Brownian particle dynamics in spatially periodic symmetric systems that is driven by time-periodic symmetric driving and constant bias is investigated numerically. The Brownian dynamics is modeled by a generalized Langevin equation with exponentially correlated Gaussian thermal noise, obeying the fluctuation-dissipation theorem. We study the role of nonzero correlation time of thermal fluctuations for the occurrence of absolute negative (linear) mobility (ANM) near zero bias, negative-valued, nonlinear mobility (NNM), and negative differential mobility (NDM) at finite bias away from equilibrium. We detect that a nonzero thermal correlation time can either enhance or also diminish the value of ANM. Moreover, finite thermal noise correlation can induce NDM and NNM in regions of parameter space for which such ANM and NNM behaviors are distinctly absent for limiting white thermal noise. In parts of the parameter space, we find a complex structure of regions of linear and nonlinear negative mobility: islands and tongues which emerge and vanish under parameters manipulation. While certain such anomalous transport regimes fade away with increasing temperature some specific regions interestingly remain rather robust. Outside those regimes with anomalous mobility, the ac/dc driven transport is either normal or the driven Brownian particles are not transported at all.
  Physical Review E 11/2009; 80(5 Pt 1):051121. · 2.26 Impact Factor
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  Available from: ArXiv

  Article: Dephasing of qubits by the Schr\"odinger cat

  J. Dajka, M. Mierzejewski, J. Luczka, P. Hanggi
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  ABSTRACT: We study the dephasing of a single qubit coupled to a bosonic bath. In particular, we investigate the case when the bath is initially prepared in a pure state known as the Schr\"odinger cat. In clear contradistinction to the time-evolution of an initial coherent state, the time evolutions of the purity and the coherence factor now depend on the particular choice of the Schr\"odinger cat state. We also demonstrate that the evolution of the entanglement of a two--qubit system depends on the initial conditions in a similar way. Comment: Physica E (accepted)
  05/2009;
• Source

  Available from: Lukasz Machura

  Article: Negative conductances of Josephson junctions: Voltage fluctuations and energetics

  L. Machura, M Kostur, P. Talkner, P. Hanggi, J. Luczka
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  ABSTRACT: We study a resistively and capacitively shunted Josephson junction, which is driven by a combination of time-periodic and constant currents. Our investigations concern three main problems: (A) The voltage fluctuations across the junction; (B) The quality of transport expressed in terms of the P\'eclet number; (C) The efficiency of energy transduction from external currents. These issues are discussed in different parameter regimes that lead to: (i) absolute negative conductance; (ii) negative differential conductance, and (iii) normal, Ohmic-like conductance. Conditions for optimal operation of the system are studied. Comment: 7 pages, 4 figures, Presented at the "Frontiers of Quantum and Mesoscopic Thermodynamics", 28 July - 2 August 2008, Prague, Czech Republic
  02/2009;
• Source

  Available from: Marcin Kostur

  Article: Anomalous transport in biased ac-driven Josephson junctions: Negative conductances

  M Kostur, L. Machura, P. Talkner, P. Hanggi, J. Luczka
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  ABSTRACT: We investigate classical anomalous electrical transport in a driven, resistively and capacitively shunted Josephson junction device. Novel transport phenomena are identified in chaotic regimes when the junction is subjected to both, a time periodic (ac) and a constant, biasing (dc) current. The dependence of the voltage across the junction on the dc-current exhibits a rich diversity of anomalous transport characteristics: In particular, depending on the chosen parameter regime we can identify so termed absolute negative conductance around zero dc-bias, the occurrence of negative differential conductance and, after crossing a zero conductance, the emergence of a negative nonlinear conductance in the non-equilibrium response regime remote from zero dc-bias.
  01/2008;
• Article: Kinetics of Crystal Growth Limited by Random Velocity Fields.

  M. Niemiec, W. Olchawa, Lutz Schimansky-Geier, J. Luczka
  I. J. Bifurcation and Chaos. 01/2008; 18:2673-2679.
• Source

  Available from: uni-augsburg.de

  Article: White-Noise-Induced Transport in Periodic Structures

  J. Luczka, R. Bartussek, P. Hänggi
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  ABSTRACT: Spatially periodic structures are exposed to additive Poissonian white shot noise of zero average. Because the underlying master equation no longer obeys the principle of detailed balance, these non-equilibrium fluctuations induce a macroscopic current—even in the absence of spatial asymmetry. The resulting current can be expressed in analytical closed form and we discuss its behaviour in the limits of very weak and very strong noise intensities. We find that the current increases monotonically and—in contrast to common intuition—saturates at infinitely strong noise intensity. The role of internal symmetries of the periodic structure is investigated from the viewpoint of optimizing the current amplitude at fixed noise intensity.
  EPL (Europhysics Letters) 07/2007; 31(8):431. · 2.17 Impact Factor
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  Available from: Marcin Kostur

  Article: Frequency Windows of Absolute Negative Conductance in Josephson Junctions

  L. Machura, M Kostur, P. Talkner, P. Hanggi, J. Luczka
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  ABSTRACT: We report on anomalous conductance in a resistively and capacitively shunted Josephson junction which is simultaneously driven by ac and dc currents. The dependence of the voltage across the junction on the frequency of the ac current shows windows of absolute negative conductance regimes, i.e. for a positive (negative) dc current, the voltage is negative (positive). Comment: 4 pages, 1 figure
  05/2007;
• Source

  Available from: arxiv.org

  Article: Magnetic flux in mesoscopic rings: Quantum Smoluchowski regime

  J. Dajka, L. Machura, S. Rogozinski, J. Luczka
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  ABSTRACT: Magnetic flux in mesoscopic rings under the quantum Smoluchowski regime is investigated. Quantum corrections to the dissipative current are shown to form multistable steady states and can result in statistical enhancement of the magnetic flux. The relevance of quantum correction effects is supported v ia the entropic criterion. A possible application for a qutrit architecture of quantum information is proposed. Comment: 7 pages, 2 figures
  01/2007;
• Source

  Available from: Marcin Kostur

  Article: Absolute negative mobility induced by thermal equilibrium fluctuations

  L. Machura, M Kostur, P. Talkner, J. Luczka, P. Hanggi
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  ABSTRACT: A novel transport phenomenon is identified that is induced by inertial Brownian particles which move in simple one-dimensional, symmetric periodic potentials under the influence of both a time periodic and a constant, biasing driving force. Within tailored parameter regimes, thermal equilibrium fluctuations induce the phenomenon of absolute negative mobility (ANM), which means that the particle noisily moves {\it backwards} against a small constant bias. When no thermal fluctuations act, the transport vanishes identically in these tailored regimes. There also exist parameter regimes, where ANM can occur in absence of fluctuations on grounds which are rooted solely in the complex, inertial deterministic dynamics. The experimental verification of this new transport scheme is elucidated for the archetype symmetric physical system: a convenient setup consisting of a resistively and capacitively shunted Josephson junction device.
  10/2006;
• Source

  Available from: Marcin Kostur

  Article: Quantum diffusion in biased washboard potentials: strong friction limit.

  L Machura, M Kostur, P Talkner, J Luczka, P Hänggi
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  ABSTRACT: Diffusive transport properties of a quantum Brownian particle moving in a tilted spatially periodic potential and strongly interacting with a thermostat are explored. Apart from the average stationary velocity, we foremost investigate the diffusive behavior by evaluating the effective diffusion coefficient together with the corresponding Peclet number. Corrections due to quantum effects, such as quantum tunneling and quantum fluctuations, are shown to substantially enhance the effectiveness of diffusive transport if only the thermostat temperature resides within an appropriate interval of intermediate values.
  Physical Review E 04/2006; 73(3 Pt 1):031105. · 2.26 Impact Factor
• Article: Magnetic Flux in Mesoscopic Cylinders

  J. Luczka, J. Dajka, P. Haenggi
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  ABSTRACT: Our objective here is the study of the noise-assisted generation of magnetic flux in a collection of identical mesoscopic cylinders which are coupled via mutual inductances. With thermal (Johnson--Nyquist)-fluctuations acting at finite temperature, the system can be modeled in terms of a set of Langevin equations with a corresponding Fokker--Planck equation. In the limit of infinitely many constituents, the steady-state of the system is determined by a mean-field-like, nonlinear Fokker--Planck equation. The rich complexity of the generated average flux through each cylinder and its characteristic fluctuations are investigated as a function of various parameters such as the temperature, the coupling strength and an externally applied, uniform magnetic field.
  Acta Physica Polonica Series B 04/2005; 36:1693. · 0.90 Impact Factor
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  Available from: Adam Gadomski

  Article: On temperature- and space-dimension dependent matter agglomeration in a mature growing stage

  A. Gadomski, J. M. Rubi, J. Luczka, M. Ausloos
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  ABSTRACT: Model matter agglomerations, with temperature as leading control parameter, have been considered, and some of their characteristics have been studied. The primary interest has been focused on the grain volume fluctuations, the magnitude of which readily differentiates between two commonly encountered types of matter agglomeration/aggregation processes, observed roughly for high- and low-density matter organizations. The two distinguished types of matter arrangements have been described through the (entropic) potential driving system. The impact of the potential type on the character of matter agglomeration has been studied, preferentially for (low density) matter agglomeration for which a logarithmic measure of its speed has been proposed. A common diffusion as well as mechanical relaxation picture, emerging during the mature growing stage, has been drawn using a phenomenological line of argumentation. Applications, mostly towards obtaining soft agglomerates of so-called jammed materials, have been mentioned.
  12/2004;