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Quantum security and theory of decoherence
PublicationWe sketch a relation between two crucial, yet independent, fields in quantum information research, viz. quantum decoherence and quantum cryptography. We investigate here how the standard cryptographic assumption of shielded laboratory, stating that data generated by a secure quantum device remain private unless explicitly published, is disturbed by the einselection mechanism of quantum Darwinism explaining the measurement process...

Density Functional Theory Studies on Ir Spectra of the Triphenylene Derivatives. A Scaled Quantum Mechanical Force Field Approach
Publication 
Structure of the Resource Theory of Quantum Coherence
PublicationQuantum coherence is an essential feature of quantum mechanics which is responsible for the departure between the classical and quantum world. The recently established resource theory of quantum coherence studies possible quantum technological applications of quantum coherence, and limitations that arise if one is lacking the ability to establish superpositions. An important open problem in this context is a simple characterization...

On mixed states entanglement and quantum communication: aspects of quantum channels theory
PublicationDokonano przeglądu związków miedzy stanami kwantowymi oraz kwantowymi kanałami. Wykazano, że istnienie nietypowych korelacji kwantowych (splątanie związane typu NPT) w pewnych sytuacjach pociąga za sobą nieaddytywność pojemności kanałów kwantowych.

Steering is an essential feature of nonlocality in quantum theory
PublicationA physical theory is called nonlocal when observers can produce instantaneous effects over distant systems. Nonlocal theories rely on two fundamental effects: local uncertainty relations and steering of physical states at a distance. In quantum mechanics, the former one dominates the other in a wellknown class of nonlocal games known as XOR games. In particular, optimal quantum strategies for XOR games are completely determined...

Quantum morphogenesis: A variation on Thom`s catastrophe theory.
PublicationZaproponowano nowy opis morfogenezy na poziomie kwantowym w oparciu o rozwiązania samo przełączające nieliniowego równania von Neumanna.

From fluid mechanics backgrounds to modern field theory
PublicationOur presentation keeps a historical line of reasoning, since we start from old concepts of fluid mechanics and finish on concepts of modern field theory. We want to show that some facts from the nature phenomena, which have firstly been discovered on the ground of fluid mechanics, were next incorporated into physics and later become the important pattern for whole mathematical physics. Especially, wellknown continuum models, which...

Composite shells in 6field nonlinear shell theory
PublicationW pracy przedstawiono równanie konstytutywne uwzględniające wielowarstwowość materiału powłoki. Równania wyprowadzono bazując na podejściu Equivalent Single Layer

The decay of quantum correlations between quantum dot spin qubits and the characteristics of its magneticfield dependence
PublicationWe address the question of the role of quantum correlations beyond entanglement in the context of quantum magnetometry. We study the evolution of the rescaled variant of the geometric quantum discord of two electronspin qubits interacting with an environment of nuclear spins via the hyperfine interaction. We have found that quantum correlations display a strong magneticfield sensitivity which can be utilized for decoherencedriven...

On refined constitutive equations in the sixfield theory of elastic shells
PublicationWithin the resultant sixfield shell theory, the second approximation to the complementary energy density of an isotropic elastic shell undergoing small strains is constructed. In this case, the resultant drilling couples are expressed explicitly by the stress resultants and stress couples as well as by amplitudes of the quadratic and cubic distributions of an intrinsic deviation vector. The refined 2D strainstress and stressstrain...

Sensitivity of entanglement decay of quantumdot spin qubits to the external magnetic field
PublicationWe study the decay of entanglement of quantumdot electronspin qubits under hyperfineinteractionmediated decoherence.We show that twoqubit entanglement of a single entangled initial state may exhibit decay characteristic of two disentanglement regimes in a single sample, when the externalmagnetic field is changed. The transition is manifested by the suppression of timedependent entanglement oscillations which are superimposed...

Progressive failure analysis of laminates in the framework of 6field nonlinear shell theory
PublicationThe paper presents the model of progressive failure analysis of laminates incorporated into the 6field nonlinear shell theory with nonsymmetrical strain measures of Cosserat type. Such a theory is specially recommended in the analysis of shells with intersections due to its specific kinematics including the socalled drilling rotation. As a consequence of asymmetry of strain measures, modified laminates failure criteria must...

FEM analysis of composite materials failure in nonlinear six field shell theory
PublicationThe monography deals with the problem of failure initiation in thin laminated composites. Known techniques of laminate structures modelling are briefly characterised. Eventually, shell based approach is chosen for the purpose of the description of the composite structures behaviour, as it predicts their deformation and states of stress effectively in a global sense. The nonlinear six parameter shell theory (6p theory) with asymmetric...

Dynamics based on sixfield theory of shells in the context of energyconserving scheme
PublicationPraca dotyczy zaproponowanego algorytmu zachowującego energię w całkowaniu równań ruchu powłok sprężystych sformułowanych w ramach teorii sześcioparametrowej. Zawiera podstawowe założenia konieczne do formułowania schematów i podstawowe testy numeryczne. Aproksymacja przestrzenna zagadnienia oparta jest o Metodę Elementów Skończonych zaś aproksymacja w czasie wykorzystuje regułę punktu środkowego. Przykłady analizy dynamicznej...

Estimation of Failure Initiation in Laminated Composites by means of Nonlinear SixField Shell Theory and FEM
PublicationThe monography deals with the problem of failure initiation in thin laminated composites. Known techniques of laminate structures modelling are briefly characterised. Eventually, shell based approach is chosen for the purpose of the description of the composite structures behaviour, as it predicts their deformation and states of stress effectively in a global sense. The nonlinear six parameter shell theory (6p theory) with asymmetric...

On the use of enhanced strain formulation in 6field nonlinear shell theory with asymetric strain measures
PublicationW pracy zbadano możliwość zastosowania techniki wzbogaconych odkształceń do usunięcia zjawiska blokady w elementach skończonych opracowanych w ramach 6parametrowej nieliniowej teorii powłok z niesymetrycznymi miarami odkształceń membranowych. Przedstawiono i porównano 4 warianty pol wzogacających odkształcenia

Highelectricfield quantum yield rolloff in efficient europium chelatesbased lightemitting diodes
PublicationSkonstruowano dwuwarstwowe organiczne diody EL, w których warstwa transportująca dziury była domieszkowana organicznymi kompleksami europu. Maksymalna kwantowa wydajność świecenia takich diod osiągała w polu elektrycznym 1MV/cm wartość 5% foton/elektron. Wysokopolowy spadek kwantowej wydajności świecenia zinterpretowano na gruncie modelu Onsagera dysocjacji stanów emitujących.

Vibration and buckling characteristics of nonlocal beam placed in a magnetic field embedded in Winkler–Pasternak elastic foundation using a new refined beam theory: an analytical approach
PublicationIn this article, a new refined beam theory, namely one variable firstorder shear deformation theory, has been employed to study the vibration and buckling characteristics of nonlocal beam. The beam is exposed to an axial magnetic field and embedded in Winkler–Pasternak foundation. The von Kármán hypothesis along with Hamilton’s principle has been implemented to derive the governing equations for both the vibration and buckling...

Jan Kozicki dr hab. inż. arch.
PeopleIn year 2002 after obtaining master's degree in construction was employed on Faculty of Civil and Environmental Engineering. In 2004 obtained master's degree in architecture on Faculty of Architecture focusing on a research outpost on Mars. Defended PhD in year 2007 in the field of numerical modeling. In 2013 obtained Licentiate degree in theoretical physics on University of Gdańsk. In year 2014 obtained habilitation in technical...

Quantum Coherence as a Resource
PublicationThe coherent superposition of states, in combination with the quantization of observables, represents one of the most fundamental features that mark the departure of quantum mechanics from the classical realm. Quantum coherence in manybody systems embodies the essence of entanglement and is an essential ingredient for a plethora of physical phenomena in quantum optics, quantum information, solid state physics, and nanoscale thermodynamics....

Marek Czachor prof. dr hab.
People 
Relativistic twodimensional hydrogenlike atom in a weak magnetic field
PublicationA twodimensional (2D) hydrogenlike atom with a relativistic Dirac electron, placed in a weak, static, uniform magnetic field perpendicular to the atomic plane, is considered. Closed forms of the first and secondorder Zeeman corrections to energy levels are calculated analytically, within the framework of the Rayleigh–Schrödinger perturbation theory, for an arbitrary electronic bound state. The secondorder calculations are...

Distributed correlations and information flows within a hybrid multipartite quantumclassical system
PublicationUnderstanding the nonMarkovian mechanisms underlying the revivals of quantum entanglement in the presence of classical environments is central in the theory of quantum information. Tentative interpretations have been given by either the role of the environment as a control device or the concept of hidden entanglement. We address this issue from an informationtheoretic point of view. To this aim, we consider a paradigmatic tripartite...

Unifying Aspects of Generalized Calculus
PublicationNonNewtonian calculus naturally unifies various ideas that have occurred over the years in the field of generalized thermostatistics, or in the borderland between classical and quantum information theory. The formalism, being very general, is as simple as the calculus we know from undergraduate courses of mathematics. Its theoretical potential is huge, and yet it remains unknown or unappreciated.

At the Limits of CriticalityBased Quantum Metrology: Apparent SuperHeisenberg Scaling Revisited
PublicationWe address the question of whether the superHeisenberg scaling for quantum estimation is indeed realizable. We unify the results of two approaches. In the first one, the original system is compared with its copy rotated by the parameterdependent dynamics. If the parameter is coupled to the onebody part of the Hamiltonian, the precision of its estimation is known to scale at most as N−1 (Heisenberg scaling) in terms of the number...

Practical Approach to LargeScale Electronic Structure Calculations in Electrolyte Solutions via ContinuumEmbedded LinearScaling Density Functional Theory
PublicationWe present the implementation of a hybrid continuumatomistic model for including the effects of a surrounding electrolyte in largescale density functional theory (DFT) calculations within the OrderN Electronic Total Energy Package (ONETEP) linearscaling DFT code, which allows the simulation of large complex systems such as electrochemical interfaces. The model represents the electrolyte ions as a scalar field and the solvent...

Workshop on Graph Theory
EventsThe Gdańsk Workshop on Graph Theory (GWGT) is an annual, informal workshop whose goal is to provide a forum for scientists to meet, present their work, interact, and establish collaborations in the field of Graph Theory

Electromodulation of monomer and excimer phosphorescence in vacuumevaporated films of platinum (II) complexes of 1,3di(2pyridyl)benzenes
PublicationElectric fieldmodulated photoluminescence (EML) measurements are presented for vacuumevaporated films of cyclometallated Pt (II) complexes of 1,3di(2pyridyl) benzenes used as triplet emitters in organic lightemitting diodes (OLEDs). The excimer phosphorescence is quenched by the external electric field of 2.5 MV/cm up to 25% but the same effect on monomer phosphorescence is one order of magnitude smaller. The higher quenching...

Redundant information encoding in QED during decoherence
PublicationBroadly understood decoherence processes in quantum electrodynamics, induced by neglecting either the radiation [L. Landau, Z. Phys. 45, 430 (1927)] or the charged matter [N. Bohr and L. Rosenfeld, K. Danske Vidensk. Selsk, Math.Fys. Medd. XII, 8 (1933)], have been studied from the dawn of the theory. However, what happens in between, when a part of the radiation may be observed, as is the case in many reallife situations, has...

On symmetric extendibility of quantum states and its applications
PublicationThis dissertation is focused on analysis of the symmetric extendibility of quantum states and its applications in the quantum information theory, with special attention paid to the area of quantum entanglement distillation, quantum channels theory, quantum security, and monogamy of quantum entanglement in time. We analyze geometry of the set of symmetric extendible states, i.e. such states that possess symmetric extensions and...

Automatic Regularization by Quantization in Reducible Representations of CCR: PointForm Quantum Optics with Classical Sources
PublicationElectromagnetic fields are quantized in a manifestly covariant way by means ofa class of reducible "centerofmass Nrepresentations" of the algebra of canonical commutationrelations (CCR). The fourpotential Aa(x) transforms in these representations as aHermitian fourvector field in Minkowski fourposition space (without change of gauge), butin momentum space it splits into spin1 massless photons and two massless scalars. Whatwe...

Superadditivity of two quantum information resources
PublicationEntanglement is one of the most puzzling features of quantum theory and a principal resource for quantum information processing. It is well known that in classical information theory, the addition of two classical information resources will not lead to any extra advantages. On the contrary, in quantum information, a spectacular phenomenon of the superadditivity of two quantum information resources emerges. It shows that quantum...

Consistency of Quantum Computation and the Equivalence Principle.
PublicationThe equivalence principle, being one of the building blocks of general relativity, seems to be crucial for analysis of quantum effects in gravity. In this paper we consider the relation between the equivalence principle and the consistency of quantum information processing in gravitational field. We propose an analysis with a looped evolution consisting of steps both in the gravitational field and in the accelerated reference frame....

An analysis of solar energy conversion systems based on photon and thermal processes
PublicationSolar spectral irradiance covers a fairly broad wavelength range. Solar radiation is part of the electromagnetic spectrum which is described by the concept of waveparticle duality. The corpuscular theory of electromagnetic radiation states that energy is transmitted by photons. Photons carry specific amounts of energy which can be used to convert solar energy into other types of energy, in particular electricity. The internal...

Purely quantum superadditivity of classical capacities of quantum multiple access channels
PublicationWe are studying classical capacities of quantum memoryless multiaccess channels in geometric terms and we are revealing a break of additivity of the Holevolike capacity. This effect is a purely quantum mechanical one, since, as we point out, the capacity regions of all classical memoryless multiaccess channels are additive. It is the first such effect revealed in the field of classical information transmission via quantum channels.

Quantum origins of objectivity
PublicationIn spite of all of its successes, quantum mechanics leaves us with a central problem: How does nature create a bridge from fragile quanta to the objective world of everyday experience? Here we find that a basic structure within quantum mechanics that leads to the perceived objectivity is a socalled spectrum broadcast structure. We uncover this based on minimal assumptions, without referring to any dynamical details or a concrete...

Towards Resource Theory of Coherence in Distributed Scenarios
PublicationThe search for a simple description of fundamental physical processes is an important part of quantum theory. One example for such an abstraction can be found in the distance lab paradigm: if two separated parties are connected via a classical channel, it is notoriously difficult to characterize all possible operations these parties can perform. This class of operations is widely known as local operations and classical communication....

Quantum entanglement
PublicationAll our former experience with application of quantum theory seems to say that what is predicted by quantum formalism must occur in the laboratory. But the essence of quantum formalismentanglement, recognized by Einstein, Podolsky, Rosen, and Schrödingerwaited over 70 years to enter laboratories as a new resource as real as energy. This holistic property of compound quantum systems, which involves nonclassical correlations between...

Dynamical objectivity in quantum Brownian motion
PublicationClassical objectivity as a property of quantum states —a view proposed to explain the observerindependent character of our world from quantum theory, is an important step in bridging the quantumclassical gap. It was recently derived in terms of spectrum broadcast structures for small objects embedded in noisy photonlike environments. However, two fundamental problems have arisen: a description of objective motion and applicability...

Semidefinite programming and quantum information
PublicationThis paper presents a comprehensive exploration of semidefinite programming (SDP) techniques within the context of quantum information. It examines the mathematical foundations of convex optimization, duality, and SDP formulations, providing a solid theoretical framework for addressing optimization challenges in quantum systems. By leveraging these tools, researchers and practitioners can characterize classical and quantum correlations,...

Zeroknowledge convincing protocol on quantum bit is impossible
PublicationIt is one of fundamental features of quantum formalism that o n one hand it provides a new infor mation processing resources and on the other hand puts funda mental constraints on the processing of quantum information implying “nogo” theorems for cloni ng [1–3], bit commitment [4, 5] and deleting [6] in quantum theory. Here we ask about possibilit y of “zero knowledge” scenario which, for its simplicity, can be considered as...

Electromodulation of photoluminescence in vacuumevaporated films of bathocuproine
PublicationElectric fieldmodulated photoluminescence (EML) was measured in vacuumevaporated films of bathocuproine (BCP), electrontransporting material commonly used in organic lightemitting diodes (OLEDs). The external electric field of 106 V/cm strength decreases longwavelength photoluminescence (PL) up to 10% but the same effect on shortwavelength PL is above one order of magnitude smaller. The distinctive difference between the...

No Quantum Realization of Extremal NoSignaling Boxes
PublicationThe study of quantum correlations is important for fundamental reasons as well as for quantum communication and information processing tasks. On the one hand, it is of tremendous interest to derive the correlations produced by measurements on separated composite quantum systems from within the set of all correlations obeying the nosignaling principle of relativity, by means of informationtheoretic principles. On the other hand,...

Quantum metrology: Heisenberg limit with bound entanglement
PublicationQuantum entanglement may provide a huge boost in the precision of parameter estimation. However, quantum metrology seems to be extremely sensitive to noise in the probe state. There is an important still open question: What type of entanglement is useful as a resource in quantum metrology? Here we raise this question in relation to entanglement distillation. We provide a counterintuitive example of a family of bound entangled states...

Dynamical description of quantum computing: generic nonlocality of quantumnoise
PublicationWe develop a dynamical nonMarkovian description of quantum computing in the weakcoupling limit, in the lowestorder approximation. We show that the longrange memory of the quantum reservoir (such as the 1/t4 one exhibited by electromagnetic vacuum) produces a strong interrelation between the structure of noise and the quantum algorithm, implying nonlocal attacks of noise. This shows that the implicit assumption of quantum error...

Quantum corrections to 4 model solutions and applications to Heisenberg chain dynamics
PublicationThe Heisenberg spin chain is considered in φ^4 model approximation. Quantum corrections to classical solutions of the onedimensional φ^4 model within the correspondent physics are valuated with account of rest d − 1 dimensions of a ddimensional theory. A quantization of the model is considered in terms of space time functional integral. The generalized zetafunction formalism is used to renormalize and evaluate the functional...

Quantum corrections to phi^4 model solutions and applications to Heisenberg chain dynamics
PublicationThe Heisenberg spin chain is considered in φ^4 model approximation. Quantum corrections to classical solutions of the onedimensional φ^4 model within the correspondent physics are evaluated with account of rest d−1 dimensions of a ddimensional theory. A quantization of the model is considered in terms of spacetime functional integral. The generalized zetafunction formalism is used to renormalize and evaluate the functional integral...

Experimental certification of an informationally complete quantum measurement in a deviceindependent protocol
PublicationMinimal informationally complete positive operatorvalued measures (MICPOVMs) are special kinds of measurement in quantum theory in which the statistics of their d2outcomes are enough to reconstruct any ddimensional quantum state. For this reason, MICPOVMs are referred to as standard measurements for quantum information.Here, we report an experiment with entangled photon pairs that certifies, for what we believe is the first...

Quantum corrections to quasiperiodic solution of SineGordon model and periodic solution of phi^4 model
PublicationAnalytical form of quantum corrections to quasiperiodic solution of SineGordon model and periodic solution of phi^4 model is obtained through zeta function regularisation with account of all rest variables of a ddimensional theory. Qualitative dependence of quantum corrections on parameters of the classical systems is also evaluated for a much broader class of potentials u(x) = b^2 f(bx) + C with b and C as arbitrary real constants

Applications of semidefinite optimization in quantum information protocols
PublicationThis work is concerned with the issue of applications of the semidefinite programming (SDP) in the field of quantum information sci ence. Our results of the analysis of certain quantum information protocols using this optimization technique are presented, and an implementation of a relevant numerical tool is introduced. The key method used is NPA discovered by Navascues et al. [Phys. Rev. Lett. 98, 010401 (2007)]. In chapter...