# Jasmina M Jeknic-DugicUniversity of Niš | NIS · Department of Physics (PMF)

Jasmina M Jeknic-Dugic

PhD in Theoretical Physics

## About

61

Publications

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267

Citations

## Publications

Publications (61)

We provide a simple, rigorous and clearly defined class of dynamical maps for which the map's invertibility is a witness of the map's Markovianity. This novel witness of Markovianity sheds some new light on the standard and non-standard approaches and definitions of Markovian dynamical maps.

Dynamical stability is a prerequisite for control and functioning of desired nanomachines. We utilize the Caldeira-Leggett master equation to investigate dynamical stability of molecular cogwheels modeled as a rigid, propeller-shaped planar rotator. To match certain expected realistic physical situations, we consider a weakly nonharmonic external p...

Dynamical stability is a prerequisite for control and functioning of desired nano-machines. We utilize the Caldeira-Leggett master equation to investigate dynamical stability of molecular cogwheels modeled as a rigid, propeller-shaped planar rotator. In order to match certain expected realistic physical situations, we consider a weakly nonharmonic...

For some typical open quantum system Markovian processes we show the absence of the ensemble "unraveling" of the dynamics. The unraveling we are concerned with is not directly linked with the so-called piece-wise-deterministic processes unraveling. The general Markovian scenario is briefly considered. Comparison of our results with the similar resu...

We briefly review the conceptual basis of the recently introduced novel concept of the so-called Local Time in quantum theory. An emphasis is placed on certain cosmological aspects.

We pursue the quantum-mechanical challenge to the efficient market hypothesis for the stock market by employing the quantum Brownian motion model. We utilize the quantum Caldeira-Leggett master equation as a possible phenomenological model for the stock-market-prices fluctuations while introducing the external harmonic field for the Brownian partic...

The subtle and technically intricate issue of the role of the initial correlations for the complete positivity of the open system's dynamics is discussed in a specific context. Presentation of the general statements is made technically easy and conceptually clear by addressing complete positivity of dynamics of certain subsystems of an open composi...

We investigate dynamical stability of a single propeller-like
shaped molecular cogwheel modelled as the fixed-axis rigid rotator. In the
realistic situations, rotation of the finite-size cogwheel is subject of the envi-
ronmentally-induced Brownian-motion effect that we describe by utilizing the
quantum Caldeira-Leggett master equation. Assuming th...

The ongoing progress in quantum theory emphasizes the crucial role of the very basic principles of quantum theory. However, this is not properly followed in teaching quantum mechanics on the graduate and undergraduate levels of physics studies. The existing textbooks typically avoid the axiomatic presentation of the theory. We emphasize usefulness...

The Kraus form of the completely positive dynamical maps is appealing from the mathematical and the point of the diverse applications of the open quantum systems theory. Unfortunately, the Kraus operators are poorly known for the two-qubit processes. In this paper, we derive the Kraus operators for a pair of interacting qubit, while the strength of...

Microscopic Hamiltonian models of the composite system “open system + environment” typically do not provide the operator-sum Kraus form of the open system’s dynamical map. With the use of a recently developed method (Andersson et al. J. Mod. Opt. 54, 1695 2007), we derive the Kraus operators starting from the microscopic Hamiltonian model, i.e., fr...

We employ the Stern-Gerlach experiment to highlight the basics of a minimalist, non-interpretational top-down approach to quantum foundations. Certain benefits of the "quantum structural studies" (QSS) highlighted here are detected and discussed. While the top-down approach can be described without making any reference to the fundamental structure...

The structural aspects of composite quantum systems in the foundation, interpretation and application of quantum theory is an increasingly prominent topic of physics research. As an emerging field, it seeks to understand the origins of the classical world of experience from the quantum level. Quantum Structural Studies presents conceptual fundament...

We derive explicit expressions for the first and second moments as well as the correlation function for a planar (one-dimensional) quantum Brownian rotator placed in the external harmonic potential. Our results directly provide the standard deviations for the azimuthal angle and the canonically conjugate angular momentum for the rotator. We find th...

Ever since Schrödinger, Time in quantum theory is postulated Newtonian for every reference frame. With the help of certain known mathematical results, we show that the concept of the so-called Local Time allows avoiding the postulate. In effect, time appears as neither fundamental nor universal on the quantum-mechanical level while being consistent...

Ever since Schrodinger, the time-dependent Schrodinger equation has been regarded as the fundamental physical law of the unitary-only quantum theory. However, while the origin of time for non-conservative systems can be traced back to the environmental influence, this procedure is inapplicable for the closed (conservative) quantum systems. Hence th...

Recently we pointed out the so-called Local Time Scheme [J. Jekni\' c-Dugi\'c
et al, (2014) Ref. [1]] as a novel approach to quantum foundations that solves
the preferred pointer-basis problem. In this paper we introduce and analyze in
depth a rather non-standard dynamical map that is imposed by the scheme. On one
hand, the map does not allow for i...

There is current interest in investigating which variables play an important role in the physical processes with an open composite quan- tum system that ranges from the foundational issues to the tasks of diverse applications in quantum physics and technology. In this paper we contrast the local versus the collective classical-like behavior of a pa...

We employ the Stern-Gerlach experiment to highlight the basics of a
minimalist, non-interpretational top-down approach to quantum foundations.
Certain benefits of the here highlighted "quantum structural studies" are
detected and discussed. While the top-down approach can be described without
making any reference to the fundamental structure of a c...

Microscopic Hamiltonian models of the composite system "open system +
environment" typically do not provide the operator-sum Kraus form but a
differential (master equation) form of the open system's dynamical map. Due to
the recently developed method [Andersson et al, J. Mod. Opt. \textbf{54}, 1695
(2007)], we derive the novel, generalized Kraus op...

A quantum mechanical analysis of the decomposability of quantum systems into
subsystems provides support for the so-called "attenuated Eliminative Ontic
Structural Realism" within Categorical Structuralism studies in physics.
Quantum subsystems are recognized as non-individual, relationally defined
objects that deflate or relax some standard object...

Realistic many-particle systems dynamically exchange particles with their environments. In classical physics, small variations in the number of constituent particles are commonly considered practically irrelevant. However, in the quantum mechanical context, such and similar structural variations are generically taxed due to the so-called Entangleme...

Realistic many-particle systems dynamically exchange particles with their
environments. In classical physics, small variations in the number of
constituent particles are commonly considered practically irrelevant. However,
in the quantum mechanical context, such and similar structural variations are
generically taxed due to the so-called Entangleme...

In the context of the macroscopic quantum phenomena of the second kind, we hereby seek for a solution-in-principle of the long standing problem of the polymer folding, which was considered by Levinthal as (semi)classically intractable. To illuminate it, we applied quantum-chemical and quantum decoherence approaches to conformational transitions. Ou...

Solution to the problem of asymptotic completeness in many-body scattering
theory offers a specific view of the quantum unitary dynamics. It allows
straightforward introduction of local time for every many-body system with the
virtually arbitrary interactions within the system. While every single system
sustains quantum coherence through unitary dy...

We offer a systematic account of decomposition of quantum systems into parts.
Different decompositions (structures) are mutually linked via the proper linear
canonical transformations. Different kinds of structures, as well as their
relations, are considered. Emphasis is placed on mutually global and
irreducible structures. Is there a privileged st...

It is shown that a choice of degrees of freedom of a bipartite continuous variable system determines the amount of non-classical correlations (quantified by discord) in the system’s state. Non-classical correlations (that include entanglement as a special kind of correlations) are ubiquitous for such systems. For a quantum state, if there are not n...

The composite systems can be non-uniquely decomposed into parts (subsystems). Not all decompositions (structures) of a composite system are equally physically relevant. In this paper we answer on theoretical ground why it may be so. We consider a pair of mutually un-coupled modes in the phase space representation that are subjected to the independe...

There is current interest in dynamical description of dif- ferent
decompositions of a quantum system into subsystems. We investi- gate usefulness
of the Nakajima-Zwanzig projection method in this context. Particularly, we are
interested in simultaneous description of dynamics of open systems pertaining
to dierent system-environment splits (decompo-...

We present the foundations of a new emerging interpretation of quantum theory bearing wide-range implications. Physical basis of the interpretation is non-questionable yet relatively new - it relies on the different structures (decompositions into parts, subsystems) of the quantum Universe. We compare the mutually irreducible structures of the Univ...

Modern quantum theory introduces quantum structures (decompositions into
subsystems) as a new discourse that is not fully comparable with the
classical-physics counterpart. To this end, so-called Entanglement Relativity
appears as a corollary of the universally valid quantum mechanics that can
provide for a deeper and more elaborate description of...

Recent observation that almost all quantum states bear non-classical
correlations [A. Ferraro et al, Phys. Rev. A 81, 052328 (2010)] may seem to
imply that the Markovian bipartite systems are practically deprived of zero
discord states. Nevertheless, complementary to the result of Ferraro et al, we
construct a model of a Markovian bipartite system...

Modern quantum information theory provides new tools for investigating the
decoherence-induced "classicality" of open quantum systems. Recent observation
that almost all quantum states bear non-classical correlations [A. Ferraro {\it
et al}, Phys. Rev. A {\bf 81}, 052318 (2010)] distinguishes the zero-discord
classicality essentially as a pathology...

Quantum information resources quantified by non-zero discord are ubiquitous
for the continuous-variables bipartite systems. Complementary to this, we
formally construct a model characterized by zero two-way discord for
arbitrarily long time interval. The model is classical in the sense it does not
support quantum information processing. We point ou...

It is shown that a choice of degrees of freedom of a bipartite continuous variable system determines amount of non-classical correlations (quantified by discord) in the system's state. Non-classical correlations (that include entanglement as a special kind of correlations) are ubiquitous for such systems. For a quantum state, if there are not non-c...

We observe a Quantum Brownian Motion (QBM) Model Universe in conjunction with
recently established Entanglement Relativity and Parallel Occurrence of
Decoherence. The Parallel Occurrence of Decoherence establishes the
simultaneous occurrence of decoherence for two mutually irreducible structures
(decomposition into subsystems) of the total QBM mode...

We present the foundations of a new emerging interpretation of quantum theory
bearing wide-range implications. Physical basis of the interpretation is
non-questionable yet relatively new--it relies on the different structures
(decompositions into parts, subsystems) of the quantum Universe. We compare the
mutually irreducible structures of the Unive...

Our objective is to demonstrate an inconsistency with both the original and
modern Everettian Many Worlds Interpretations. We do this by examining two
important corollaries of the universally valid quantum mechanics in the context
of the Quantum Brownian Motion (QBM) model: "Entanglement Relativity" and the
"parallel occurrence of decoherence." We...

For the standard quantum Brownian motion (QBM) model, we point out the occurrence of simultaneous (parallel), mutually irreducible and autonomous decoherence processes. Besides the standard Brownian particle, we show that there is at least another system undergoing the dynamics described by the QBM model. We do this by selecting the two mutually ir...

Recently, we pointed out the possible inconsistency in the very foundations of the Everett MWI (or a Multiverse) theory. Here, we place some emphasis on the very basic notions underlying our conclusion yet motivated by certain, recently raised clever observations in this regard. Comment: $ pages, no fuigures. Comments welcome

Two unresolved issues of the (semi)classically addressed problems in molecular biophysics are unreasonably long time necessary for change of biopolymer conformati-ons and long-range directedness of selective biomolecular recognition processes – implying their essential quantum origin. In this paper, several possible quantum approaches to biomole-cu...

The complex (composite) systems such as the Universe allow the different decompositions into subsystems. The Everett's Many Times Interpretation (MWI) heavily relies on the occurrence of decohernce that should provide the classical reality for the Worlds. However, applying the occurrence of decoherence as the sufficient condition for the classical...

Two unresolved issues of the (semi)classically addressed problems in mole-cular biophysics are unreasonably long time necessary for change of biopolymer conformati-ons and long-range directedness of selective biomolecular recognition processes – implying their essential quantum origin. In this paper, several possible quantum approaches to biomole-c...

We point out certain inconsistency in the foundations of the standard
adiabatic method in quantum theory of molecules. As an alternative, we
develop a particular approach that overcomes the appointed
inconsistency. Based on this new approach, some interesting physical
results come to the scope. First, we point out that the adiabatic method
is subst...

We discuss the quantum locality (non-transfer of information) for a pair of mutually interacting systems, and point out the relaxed locality. The models fulfilling the relaxed locality condition can serve as a guide for quantum engineers in designing quantum-information hardware.

The large-molecules conformational transitions problem (the 'protein
folding problem') is an open issue of vivid current science research
work of fundamental importance for a number of modern science
disciplines as well as for nanotechnology. Here, we elaborate the
recently proposed quantum-decoherence-based approach to the issue.
First, we emphasi...

The large molecules lie in the “border territory" between the “quantum" and the “classical". To which extent one should employ
the classical or quantum-mechanical methods in describing their behavior is an open issue. To this end, the problem of the
large-molecules conformational stability and transitions is typical. While the small or medium-size...

The Stern-Gerlach experiment is a paradigm of the quantum measurement of spin. Its physical interpretation is in intimate relation with the physical basis of the current research in the atomic (molecular) nanofabrication procedures. Nevertheless, interpretation of the experiment is an open issue yet. Here, we give the arguments for the physical non...

The standard interpretation of the Stern-Gerlach experiment assumes that the atomic center-of-mass plays the role of "quantum apparatus" for the atomic spin. Following a recent, decoherence-based, model fitting with this interpretation, we investigate whether or not such model can be constructed. Our conclusions are somewhat surprising: only if the...

The problem of “what is ‘system’?” is in the very foundations of modern quantum mechanics. Here, we point out the interest
in this topic in the information-theoretic context. E.g., we point out the possibility to manipulate a pair of mutually non-interacting,
non-entangled systems to employ entanglement of the newly defined “(sub)systems” consistin...

Decomposition of a composite system C into different subsystems, A + B or D + E, may help in avoiding decoherence. For example, the environment-induced decoherence for an A+B system need not destroy entanglement present in the D + E system (A + B = C = D + E). This new approach opens some questions also in the foundations of the quantum computation...

The complex behavior of microparticles in a solution calls for different theoretical backgrounds. Here, we follow the line of two, recently developed theories on individuality, on the one hand, and conformational transitions of macromolecules in a solution, on the other. Given as separate theories, the two models may raise certain controversy in re...

We discuss the possibility of making the initial definitions of mutually
different (possibly interacting, or even entangled) systems in the
context of decoherence theory. We point out relativity of the concept of
elementary physical system as well as point out complementarity of the
different possible divisions of a composite system into
“subsystem...

New concepts in nuclear reactor technology require precise neutron reaction data in the intermediate and high energy range. At present, experimental and evaluated nuclear data, particularly for (n, xn) reactions, are very scarce. Moreover, real discrepancies exist between different databases. The lack of experimental data is essentially due to the...

A composite quantum system can be decomposed into subsystems in the different
ways. For some relevant models of the decoherence theory, we investigate the
occurrence of decoherence for the different decompositions of a composite
system "system plus environment". The decompositions are mutually related by
the proper linear canonical transformations...

1 Elektrotehnički fakultet, Beograd, Srbija 2 Prirodnomatematički fakultet, Kragujevac, Srbija 3 Prirodnomatematički fakultet, Niš, Srbija 4 Tehnološko-metalurški fakultet, Beograd, Srbija 5 Biološki institut, Beograd, Srbija 6 Institut Vinča, Beograd, Srbija 7 School of Electrical and Computer Engineering, RMIT, Melbourne, Australia 8 Kriminalisti...

Typically, free will is a philosophical and theological an issue. Modern cosmology also tempts to say its word in this regard. In this paper we point out that "free will" is of interest for interpretation of quantum mechanics as a universally valid physical (nonrelativistic) theory. Our aim is not to quantify free will – this is an issue of modern...

## Projects

Project (1)