1,819 research outputs found
Vortex bound states in dimerized π-flux optical lattices: Characterization, state preparation, and current measurement
No full textLattice models display bound states for repulsive interactions that smoothly connect to high-energy twoparticle states of doubly occupied sites, namely doublons, for strong on-site interactions. In this work, we show that a distinct type of repulsively bound states, namely vortex bound states of two bosons, appear in dimerized square lattices pierced by a uniform pi flux for moderate interactions. By focusing on a ladder geometry as an illustrative example, we characterize their properties, including chirality-changing decay channels induced by flux detuning, and we develop protocols to perform state preparation in optical lattices via adiabatic sequences or recently developed current imprinting methods. Finally, we show how to measure currents and thus chirality by quenching the system onto isolated pairs of nearest-neighbor sites and then sampling the corresponding dynamics. These results can also provide an experimentally realistic strategy for state preparation and probing of chiral gapped many-body phases in optical lattices
A New 4-DOF fully parallel robot with decoupled rotation for five-axis micromachining applications
No full textWe present a novel 4-DOF (degrees of freedom) parallel robot designed for five-axis micromachining applications. Two of its five telescoping legs operate simultaneously, thus acting as an extensible parallelogram linkage, and in conjunction with two other legs control the position of the tooltip. The fifth leg controls the tilt of the end-effector (a spindle), while a turntable fixed at the base of the robot controls the swivel of the workpiece. The robot is capable of tilting its end-effector up to 90 deg, for any tooltip position. In this paper, we study the mobility of the new parallel kinematic machine (PKM), describe its inverse and direct kinematic models, then study its singularities, and analyze its workspace. Finally, we propose a potential mechanical design for this PKM utilizing telescopic actuators as well as the procedure for optimizing it. In addition, we discuss the possibility of using constant-length legs and base-mounted linear actuators in order to increase the volume of the workspace
Life-imprisonment penalty in the European Court of Human Rights case-law: Ukraine perspective
No full textStepanenko A. S. Life-imprisonment penalty in the European Court of Human Rights case-law: Ukraine perspective / A. S. Stepanenko // ECHR’s Jurisprudence in Digital Era : proceedings of the Int. sci. conf. (Odesa, May 31 – June 1, 2019) / MES of Ukraine, Nat. Univ. “Odes. Acad. of Law”, SRC NALSU ; exec. eds. H. A. Ulianova, V. A. Tuliakov. – Odesa : Publishing house “Helvetika”, 2019. – P. 202-205
Reconciliation of the Parties as a Way to Solve the Criminal-Legal Conflict
No full textStepanenko O. Reconciliation of the Parties as a Way to Solve the Criminal-Legal Conflict / O. Stepanenko, A. Stepanenko, A. Israielian // Amazonia Investiga. – Vol. 9. - Issue 28. – Editorial Primmate S. A. S., 2020. – P. 288-295.The article explores the problem of resolving a criminal-legal conflict (which involves a person who has committed a socially dangerous act) through reconciliation. The relevance of the research topic is due to the fact that the legal conflict requires a binding solution, as it affects the most important social values. The purpose of this article is to disclose the nature and importance of reconciliation as a way of resolving a criminal-legal conflict. The authors used an analysis method, a synthesis method, a logical method, a historical method, and a formal legal method to write this article. According to the results of the study, the authors concluded that the application of criminal liability for reconciliation of the perpetrator with the victim is effective for all parties to the criminal-legal conflict. Moreover, for the state as a party to the criminal-legal conflict, such a way of resolving, is also effective because of the fact that the achievement of the tasks of criminal responsibility with the minimum cost of resources is the restoration of the rights of the victim.Стаття досліджує проблему вирішення кримінально-правового конфлікту (в який вступає людина, що вчинила суспільно небезпечне діяння) шляхом примирення. Актуальність теми дослідження обумовлена тим, що кримінально-правовий конфлікт, потребує обов’язкового вирішення, оскільки зачіпає найбільш значущі суспільні цінності. Метою даної статті є розкриття сутності та значення примирення як способу вирішення кримінально-правового конфлікту. Автори використали метод аналізу, метод синтезу, логічний метод, історичний метод та формально-юридичний метод для написання даної статті. За результатами приведеного дослідження автори дійшли висновку, що застосування звільнення від кримінальної відповідальності у зв’язку з примирення винного з потерпілим є ефективним для всіх учасників кримінально-правового конфлікту. Більш того, для держави, як учасника кримінально-правого конфлікту, такий шлях його розв’язання є також ефективних в силу того, що відбувається досягнення завдань кримінальної відповідальності з мінімальними затратами ресурсів, відбувається відновлення прав потерпілого
Topological States of Interacting Photon Pairs Emulated in a Topolectrical Circuit
No full textIn the present work, we study the formation of topological edge states of bound photon pairs, doublons. We consider a one-dimensional array of optical microresonators with tunneling nearest-neighbor couplings, with two photons traveling along the array. Considering the interaction between photons that share the same resonator and taking into account two-photon tunneling processes, we construct a system that supports topological edge states of doublons and does not support any edge states in the single-photon regime. Thus, we provide an example of interaction-induced topological states of quantum light. To illustrate our findings, we perform an analog emulation of the proposed system applying topolectrical circuit platform. We demonstrate that the eigenstates of the Hamiltonian describing initial two-particle quantum problem can be exactly mapped to the eigenmodes of a two-dimensional classical electric circuit composed of inductors and capacitors. We realize such a circuit working at kHz frequencies and study it experimentally. After obtaining the signatures of the two-photon edge state in the resonance spectrum of the circuit, we perform a reconstruction of the corresponding eigenmode and thus provide the direct evidence of the edge state formation. To demonstrate the topological origin of this doublon edge state, we extract the associated topological invariant directly from the experimental data. Obtained experimental results fully support our theoretical predictions and provide valuable insights into topological protection in interacting quantum systems and its emulation with classical setups
Topological edge states of interacting photon pairs emulated in a topolectrical circuit
No full textTopological physics opens up a plethora of exciting phenomena allowing to engineer disorder-robust unidirectional flows of light. Recent advances in topological protection of electromagnetic waves suggest that even richer functionalities can be achieved by realizing topological states of quantum light. This area, however, remains largely uncharted due to the number of experimental challenges. Here, we take an alternative route and design a classical structure based on topolectrical circuits which serves as a simulator of a quantum-optical one-dimensional system featuring the topological state of two photons induced by the effective photon-photon interaction. Employing the correspondence between the eigenstates of the original problem and circuit modes, we use the designed simulator to extract the frequencies of bulk and edge two-photon bound states and evaluate the topological invariant directly from the measurements. Furthermore, we perform a reconstruction of the two-photon probability distribution for the topological state associated with one of the circuit eigenmodes
Epistolary achievement as a source for biographic articles in EMU (Survey of some historiographic publications by Mykola Stepanenko)
No full textThe survey is devoted to two publications: Stepanenko, M. (Ed.). (2016). Lysty Yuriia Shevelova do Oleksy Izarskoho. Poltava; Stepanenko, M. (Ed.). (2016). Lysty do Olesia Honchara (vol. 1-2). Kyiv.Огляд присвячено двом виданням: Листи Юрія Шевельова до Олекси Ізарського / Упоряд. М. Степаненко. Полтава, 2014; Листи до Олеся Гончара: У 2 кн. /
Упоряд. М. Степаненко. Київ, 2016
Solving Guarded Domain Equations in Presheaves over Ordinals and Mechanizing It
No full textConstructing solutions to recursive domain equations is a well-known, important problem in the study of programs and programming languages. Mathematically speaking, the problem is finding a fixed point (up to isomorphism) of a suitable functor over a suitable category. A particularly useful instance, inspired by the step-indexing technique, is where the functor is over (a subcategory of) the category of presheaves over the ordinal ω and the functors are locally-contractive, also known as guarded functors. This corresponds to step-indexing over natural numbers. However, for certain problems, e.g., when dealing with infinite non-determinism, one needs to employ trans-finite step-indexing, i.e., consider presheaf categories over higher ordinals. Prior work on trans-finite step-indexing either only considers a very narrow class of functors over a particularly restricted subcategory of presheaves over higher ordinals, or treats the problem very generally working with sheaves over an arbitrary complete Heyting algebra with a well-founded basis.
In this paper we present a solution to the guarded domain equations problem over all guarded functors over the category of presheaves over ordinal numbers, as well as its mechanization in the Rocq Prover. As the categories of sheaves and presheaves over ordinals are equivalent, our main contribution is simplifying prior work from the setting of the category of sheaves to the setting of the category of presheaves and mechanizing it - presheaves are more amenable to mechanization in a proof assistant
Gustavo Leyva, Álvaro Peláez y Pedro Stepanenko (comp.) : Los Rostros de la Razón: Immanuel Kant desde Hispanoamérica, México, Ed. UAM-Cuajimalpa/Anthropos, 2018
No full textLos rostros de la razón: Immanuel Kant desde Hispanoamérica. 3 Volúmenes. Editado por Gustavo Leyva, Álvaro Peláez y Pedro Stepanenko. México, Ed. UAM-Cuajimalpa/Anthropos, 2018, 727 pp
- …
