Home

Artykuły (WFAIS) Przeglądanie wg autora "Kossakowski, Andrzej"

Repozytorium Uniwersytetu Mikołaja Kopernika

Artykuły (WFAIS) Przeglądanie wg autora "Kossakowski, Andrzej"

Sortuj wg: Porządek: Wyników:

  • A class of Bell diagonal states and entanglement witnesses 
    Chruściński, Dariusz; Kossakowski, Andrzej; Młodawski, Krzysztof; Matsuoka, Takashi (2010)
    We analyze special class of bipartite states - so called Bell diagonal states. In particular we provide new examples of bound entangled Bell diagonal states and construct the class of entanglement witnesses diagonal in the ...
  • A class of commutative dynamics of open quantum systems 
    Chruściński, Dariusz; Kossakowski, Andrzej; Aniello, P.; Marmo, Giuseppe; Ventriglia, F. (2010-04-08)
    We analyze a class of dynamics of open quantum systems which is governed by the dynamical map mutually commuting at different times. Such evolution may be effectively described via spectral analysis of the corresponding ...
  • A class of positive atomic maps 
    Chruściński, Dariusz; Kossakowski, Andrzej (2007-11-28)
    We construct a new class of positive indecomposable maps in the algebra of `d x d' complex matrices. These maps are characterized by the `weakest' positivity property and for this reason they are called atomic. This class ...
  • A new class of states with positive partial transposition 
    Chruściński, Dariusz; Kossakowski, Andrzej (2006-04-03)
    We construct a new class of PPT states for bipartite "d x d" systems. This class is invariant under the maximal commutative subgroup of U(d) and contains as special cases almost all known examples of PPT states. Theses ...
  • Bell diagonal states with maximal abelian symmetry 
    Chruściński, Dariusz; Kossakowski, Andrzej (2010-11-02)
    We provide a simple class of 2-qudit states for which one is able to formulate necessary and sufficient conditions for separability. As a byproduct we generalize well known construction provided by Horodecki et al. for ...
  • From Markovian semigroup to non-Markovian quantum evolution 
    Chruściński, Dariusz; Kossakowski, Andrzej (2010-10-22)
    We provided a class of legitimate memory kernels leading to completely positive trace preserving dynamical maps. Our construction is based on a simple normalization procedure. Interestingly, when applied to the celebrated ...
  • General form of quantum evolution 
    Chruściński, Dariusz; Kossakowski, Andrzej (2010-06-14)
    We propose a complete treatment of a local in time dynamics of open quantum systems. In this approach Markovian evolution turns out to be a special case of a general non-Markovian one. We provide a general representation ...
  • Geometry of quantum states: new construction of positive maps 
    Chruściński, Dariusz; Kossakowski, Andrzej (2009-02-05)
    We provide a new class of positive maps in matrix algebras. The construction is based on the family of balls living in the space of density matrices of n-level quantum system. This class generalizes the celebrated Choi map ...
  • How to construct entanglement witnesses 
    Chruściński, Dariusz; Kossakowski, Andrzej (2007-12-07)
    We present very simple method for constructing indecomposable entanglement witnesses out of a given pair -- an entanglement witness W and the corresponding state detected by W. This method may be used to produce new classes ...
  • Long-time memory in non-Markovian evolutions 
    Chruściński, Dariusz; Kossakowski, Andrzej; Pascazio, Saverio (2010-01-19)
    If the dynamics of an open quantum systems is non-Markovian, its {asymptotic} state strongly depends on the initial conditions, even if the dynamics possesses an {invariant} state. This is the very essence of memory effects. ...
  • Markovianity criteria for quantum evolution 
    Chruściński, Dariusz; Kossakowski, Andrzej (2012-01-28)
    We characterize a class of Markovian dynamics using the concept of divisible dynamical map. Moreover we provide a family of criteria which can distinguish Markovian and non-Markovian dynamics. These Markovianity criteria ...
  • Multipartite circulant states with positive partial transposes 
    Chruściński, Dariusz; Kossakowski, Andrzej (2007-10-10)
    We construct a large class of multipartite qudit states which are positive under the family of partial transpositions. The construction is based on certain direct sum decomposition of the total Hilbert space displaying ...
  • Non-Markovian quantum dynamics: local versus non-local 
    Chruściński, Dariusz; Kossakowski, Andrzej (2010-01-10)
    We analyze non-Markovian evolution of open quantum systems. It is shown that any dynamical map representing evolution of such a system may be described either by non-local master equation with memory kernel or equivalently ...
  • On circulant states with positive partial transpose 
    Chruściński, Dariusz; Kossakowski, Andrzej (2007-06-13)
    We construct a large class of quantum "d x d" states which are positive under partial transposition (so called PPT states). The construction is based on certain direct sum decomposition of the total Hilbert space displaying ...
  • On classical and quantum liftings 
    Accardi, L.; Chruściński, Dariusz; Kossakowski, Andrzej; Matsuoka, Takashi; Ohya, Masanori (2011-02-01)
    We analyze the procedure of lifting in classical stochastic and quantum systems. It enables one to `lift' a state of a system into a state of `system+reservoir'. This procedure is important both in quantum information ...
  • On measures of non-Markovianity: divisibility vs. backflow of information 
    Chruściński, Dariusz; Kossakowski, Andrzej; Rivas, Ángel (2011-03-24)
    We analyze two recently proposed measures of non-Markovianity: one based on the concept of divisibility of the dynamical map and the other one based on distinguishability of quantum states. We provide a toy model to show ...
  • On multipartite invariant states II. Orthogonal symmetry 
    Chruściński, Dariusz; Kossakowski, Andrzej (2006-02-01)
    We construct a new class of multipartite states possessing orthogonal symmetry. This new class defines a convex hull of multipartite states which are invariant under the action of local unitary operations introduced in our ...
  • On multipartite invariant states I. Unitary symmetry 
    Chruściński, Dariusz; Kossakowski, Andrzej (2006-02-01)
    We propose a natural generalization of bipartite Werner and isotropic states to multipartite systems consisting of an arbitrary even number of d-dimensional subsystems (qudits). These generalized states are invariant under ...
  • On partially entanglement breaking channels 
    Chruściński, Dariusz; Kossakowski, Andrzej (2005-11-28)
    Using well known duality between quantum maps and states of composite systems we introduce the notion of Schmidt number of a quantum channel. It enables one to define classes of quantum channels which partially break quantum ...
  • On the structure of entanglement witnesses and new class of positive indecomposable maps 
    Chruściński, Dariusz; Kossakowski, Andrzej (2006-06-26)
    We construct a new class of positive indecomposable maps in the algebra of 'd x d' complex matrices. Each map is uniquely characterized by a cyclic bistochastic matrix. This class generalizes a Choi map for d=3. It provides ...