arXiv subjects

Krzysztof Pomorski

Publications and source records attributed to Krzysztof Pomorski.

At least 19 recordsLinked to original sources

arXiv2025

CMOS-Compatible Electrostatic SWAP Gate in Silicon Quantum Dots: Justification of Tight-Binding Model and Going Beyond

We present a generalized electrostatic SWAP gate realized in a chain of two double quantum dots operated in the single-electron regime. Using a minimalist tight-binding model, we derive analytical results and corroborate them with numerical simulations. We exploit the charge anticorrelation arising from Coulomb repulsion and quantify the resulting entanglement generation. We contrast classical and quantum descriptions and show how device geometry and coupling strengths govern entanglement dynamics and gate performance. The results are relevant to cryogenic, CMOS-compatible quantum technologies and suggest a route toward large-scale semiconductor implementations of quantum logic. Finally, we outline a systematic procedure for translating classical electrostatic logic gates into single-electron quantum gates.

cond-mat.mes-hall↗

arXiv2025

Methodology of signal spectral analysis in various Kron model geometries

This work presents experimental and theoretical comparison in the modelling of the quantum wave function of single-electron in semiconductor nanowire via classical analog electronics based hardware emulator with the use of Kron concept. Thus we are able to express the semiconductor single-electron devices of linear or closed circle topology as present in position-based qubits that can be mapped essentially to one dimensional Kron model implemented experimentally. We have also represented a two dimensional single-electron wave function in Krons model and point out future experiments to be conducted.

cond-mat.mes-hall↗

arXiv2025

Collectivity of rotational motion in $^{220}$Rn and $^{226}$Ra

Calculations to reconstruct rotational level patterns in the $^{220}$Rn and $^{226}$Ra nuclei have been performed using a collective quadrupole+octupole approach with microscopic mass tensor and moments of inertia dependent on deformation and pairing degrees of freedom. The main objective is to quantitatively confirm the known experimental observations that the Rn nucleus passes from octupole vibrational to octupole deformed with increasing rotation frequency, while the Ra nucleus is relatively weakly affected by collective rotation, being octupole deformed from the beginning. The collective potential in a nine-dimensional collective space is determined using the macroscopic-microscopic method with Strutinsky and the BCS with an approximate particle number projection microscopic corrections. The corresponding Hamiltonian is diagonalized based on the projected solutions of the harmonic oscillators coupled with Wigner functions. Such an orthogonalized basis is additionally symmetrized with respect to the so-called intrinsic symmetrization group, specifically dedicated to the collective space used, to ensure the uniqueness of the Hamiltonian eigen-solutions in the laboratory frame. The response of the pairing and deformation degrees of freedom to external rotation is discussed in the variational approach, where the total energy is minimized by the deformation and pairing variables. Consequently, the corresponding microscopic moments of inertia increase with collective spin (Coriolis {\it antiparing} effect), resulting in effectively lower rotational energy levels I$^π$ with respect to pure classical-rotor pattern I(I+1). The obtained comparison of experimental and theoretical rotational energy level schemes, dipole, quadrupole and octupole transition probabilities of B(E$λ$) in $^{220}$Rn and $^{226}$Ra is satisfactory.

nucl-th↗

arXiv2025

Quaternionic description of semiconductor position-based qubits

The quaternionic description of semiconductor single-electron devices is given in the single-electron regime. The conversion scheme of complex value Hamiltonian into a quaternion is formulated for the case of single-electron semiconductor qubit and many electrostatically interacting qubits. In particular, the quantum evolution operator is presented in quaternion form for the case of one and many electrostatically interacting quantum bodies.

cond-mat.mes-hall↗

arXiv2025

Iso-scalar liquid drop model

New liquid drop model with the isospin-square dependence of the volume and surface energy terms is applied to reproduce experimentally known masses of nuclei with number of protons and neutrons larger or equal to twenty. The ground-state microscopic energy corrections are taken into account. In spite of the fact that the model contains only six adjustable parameters, the quality of mass reproduction is good, and it is comparable with other contemporary mass models. Also, the fission barrier heights of actinide nuclei evaluated using the topographical theorem of Myers and Swiatecki are close to the data.

nucl-th↗

arXiv2025

Demystifying the fusion mechanism in heavy-ion collisions: A six-dimensional Langevin dissipative dynamics approach

We present an in-depth investigation of heavy-ion fusion dynamics using a six-dimensional Langevin framework that enables unrestricted motion of the asymmetry parameter. The stochastic formalism naturally incorporates friction effects and energy fluctuations, providing a detailed understanding of the fusion process. The dynamics transition into the overdamped regime, facilitating rapid neck stabilization while effectively capturing the interplay between shape and rotational degrees of freedom. This approach achieves excellent agreement with experimental spin distributions and fusion cross-sections, establishing a robust foundation for forthcoming studies on the synthesis of superheavy elements and the exploration of the enigmatic fusion hindrance mechanism.

nucl-th↗

arXiv2023

Revisit to the yield ratio of triton and $^3$He as an indicator of neutron-rich neck emission

The neutron rich neck zone created in heavy ion reaction is experimentally probed by the production of the $A=3$ isobars. The energy spectra and angular distributions of triton and $^3$He are measured with the CSHINE detector in $^{86}$Kr +$^{208}$Pb reactions at 25 MeV/u. While the energy spectrum of $^{3}$He is harder than that of triton, known as "$^{3}$He-puzzle", the yield ratio $R({\rm t/^3He})$ presents a robust rising trend with the polar angle in laboratory. Using the fission fragments to reconstruct the fission plane, the enhancement of out-plane $R({\rm t/^3He})$ is confirmed in comparison to the in-plane ratios. Transport model simulations reproduce qualitatively the experimental trends, but the quantitative agreement is not achieved. The results demonstrate that a neutron rich neck zone is formed in the reactions. Further studies are called for to understand the clustering and the isospin dynamics related to neck formation.

nucl-ex↗

arXiv2023

Towards construction of analog solver of Schroedinger and Ginzburg-Landau equation based on Long Line

The analog electronic computers are a type of circuitry used to calculate specific problems using the physical relationships between the voltages and currents following classical laws of physics. One specific class of these circuits are computers based on the interactions between passive circuit elements. Models presented by G.Kron in 1945 are the example of using such passive elements to construct a solver for the problem of free quantum particles confined by rectangular potential. Numerical validation of Kron second model is conducted for different shapes of particle confining potential. Model introduced by Kron is generalized by introduction of non-linear resistive elements what implies deformation of Schrödinger equation solution into Ginzburg-Landau form.

cond-mat.mes-hall↗

arXiv2023

Bogomolny approach in description of superconducting structures

Bogomolny approach in the context of strong necessary conditions is formulated for the case of various superconducting and semiconductor structures. Certain results were obtained for a constant magnetic field, which experimentally corresponds to spiral-like superconducting cable placed inside solenoid.

cond-mat.supr-con↗

arXiv2023

Towards quantization Conway Game of Life

Classical stochastic Conway Game of Life is expressed by the dissipative Schrödinger equation and dissipative tight-binding model. This is conducted at the prize of usage of time dependent anomalous non-Hermitian Hamiltonians as with occurrence of complex value potential that do not preserve the normalization of wave-function and thus allows for mimicking creationism or annihilationism of cellular automaton. Simply saying time-dependent complex value eigenenergies are similar to complex values of resonant frequencies in electromagnetic resonant cavities reflecting presence of dissipation that reflects energy leaving the system or being pumped into the system. At the same time various aspects of thermodynamics were observed in cellular automata that can be later reformulated by quantum mechanical pictures. The usage of Shannon entropy and mass equivalence to energy points definition of cellular automata temperature. Contrary to intuitive statement the system dynamical equilibrium is always reflected by negative temperatures. Diffusion of mass, energy and temperature as well as phase of proposed wave function is reported and can be directly linked with second thermodynamics law approximately valid for the system, where neither mass nor energy is conserved. The concept of complex-valued mass mimics wave-function behavior. Equivalence an anomalous second Fick law and dissipative Schrödinger equation is given. Dissipative Conway Game of Life tight-binding Hamiltonian is given using phenomenological justification.

cond-mat.dis-nn↗

arXiv2023

Hybrid Schroedinger-Ginzburg-Landau (Sch-GL) approach in study of superconducting integrated structures

Various superconducting lattices were simulated and can be treated as lattices of superconducting atoms with preimposed symmetry in 1, 2 and 3 dimensions. Hybrid Schroedinger-Ginzburg-Landau approach is based on the fact of the mathematical similarity of Ginzburg-Landau (GL) and Schroedinger formalisms. Starting from Schroedinger approach by change of term V(x)-E with term $α(x)+β(x)|ψ(x)|^2$ we arrived at the Ginzburg-Landau equation. In the presented relaxation algorithm we use one and two dimensional ground energy solutions of Schroedinger equation and placed them as starting trial solution for GL relaxation method. In consecutive steps we increase the nonlinear term in the GL equation which results in achieving a stable approach of solution of GL equation. The obtained numerical results and used methodology form simulation platform bases for study of superconducting integrated structures that can model various superconducting devices. In general, one can model time-dependent geometry of superconducting structures.

cond-mat.mes-hall↗

arXiv2023

Thermodynamics in Stochastic Conway Game of Life

Cellular automata can simulate many complex physical phenomena using the power of simple rules. The presented methodological platform expresses the concept of programmable matter in which Newtons laws of motion are one of examples. Energy has been introduced as the equivalent of the Game of Life mass, which can be treated as first level of approximation. The temperature presence and propagation was calculated for various lattice topology and boundary conditions by using the Shannon entropy measure. The conducted study provides strong evidence that despite not fulfillment the principle of mass and energy conservation, the entropy, mass distribution and temperatures approaches thermodynamic equilibrium. In addition, the described cellular automata system transits from positive to a negative temperatures that stabilizes and can be treated as a signature of system dynamical equilibrium. Furthermore the system dynamics was presented in case of few species of cellular automata competing for maximum presence on given lattice with different boundary conditions.

nlin.CG↗

arXiv2022

Fission Fragments Mass Yields of Actinide Nuclei

A new, rapidly convergent Fourier over spheroid parametrization is developed to describe the shape of a fissioning nucleus: its elongation, non-axiality and left-right asymmetry and neck formation. The 4D Potential Energy Surfaces (PES) of even-even actinide nuclei are evaluated within the macro-micro model. The Langevin trajectories generated on such PESs allow for obtaining the fission fragments' mass and kinetic energy yields. The charge equilibration at the scission configuration and the post-scission neutron emission are also discussed.

nucl-th↗

arXiv2022

Observing the Ping-pong Modality of Isospin Degree of Freedom in Cluster Emission from Heavy Ion Reactions

Two-body correlations of the isotope-resolved light and heavy clusters are measured in $^{86}$Kr+$^{\rm 208}$Pb reactions at 25 MeV/u. The yield and kinetic variables of the $A=3$ isobars, triton and $^3$He, are analyzed in coincidence with the heavy clusters of $7\le A \le 14$ emitted at the earlier chance. While the velocity spectra of both triton and $^3$He exhibit scaling behavior over the type of the heavy clusters, the yield ratios of ${\rm t/^3He}$ correlate reversely to the neutron-to-proton ratio $N/Z$ of the latter, showing the ping-pong modality of the $N/Z$ of emitted clusters. The commonality that the $N/Z$ of the residues keeps the initial system value is extended to the cluster emission in heavy ion reactions. The comparison of transport model calculations to the data is discussed.

nucl-ex↗

arXiv2022

Equivalence between finite state stochastic machine, non-dissipative and dissipative tight-binding and Schroedinger model

The mathematical equivalence between finite state stochastic machine and non-dissipative and dissipative quantum tight-binding and Schroedinger model is derived. Stochastic Finite state machine is also expressed by classical epidemic model and can reproduce the quantum entanglement emerging in the case of electrostatically coupled qubits described by von-Neumann entropy both in non-dissipative and dissipative case. The obtained results shows that quantum mechanical phenomena might be simulated by classical statistical model as represented by finite state stochastic machine. It includes the quantum like entanglement and superposition of states. Therefore coupled epidemic models expressed by classical systems in terms of classical physics can be the base for possible incorporation of quantum technologies and in particular for quantum like computation and quantum like communication. The classical density matrix is derived and described by the equation of motion in terms of anticommutator. Existence of Rabi like oscillations is pointed in classical epidemic model. Furthermore the existence of Aharonov-Bohm effect in quantum systems can also be reproduced by the classical epidemic model or in broader sense by finite state stochastic machine. Every quantum system made from quantum dots and described by simplistic tight-binding model by use of position-based qubits can be effectively described by classical statistical model encoded in finite stochastic state machine with very specific structure of S matrix that has twice bigger size as it is the case of quantum matrix Hamiltonian. Furthermore the description of linear and non-linear stochastic finite state machine is mapped to tight-binding and Schroedinger model. The concept of N dimensional complex time is incorporated into tight-binding model, so the description of dissipation in most general case is possible.

quant-ph↗

arXiv2022

On the Stability of Superheavy Nuclei

Potential energy surfaces of even-even superheavy nuclei are evaluated within the macroscopic-microscopic approximation. A very rapidly converging analytical Fourier-type shape parametrization is used to describe nuclear shapes throughout the periodic table, including those of fissioning nuclei. The Lublin Strasbourg Drop and another effective liquid-drop type mass formula are used to determine the macroscopic part of nuclear energy. The Yukawa-folded single-particle potential, the Strutinsky shell-correction method, and the BCS approximation for including pairing correlations are used to obtain microscopic energy corrections. The evaluated nuclear binding energies, fission-barrier heights, and Q-alpha energies show a relatively good agreement with the experimental data. A simple one-dimensional WKB model a la Swiatecki is used to estimate spontaneous fission lifetimes, while alpha-decay probabilities are obtained within a Gamow-type model.

nucl-th↗

arXiv2022

Reconstruction of Fission Events in Heavy Ion Reactions with CSHINE

We report the reconstruction method of the fast fission events in 25 MeV/u $^{86}$Kr +$^{208}$Pb reactions at the Compact Spectrometer for Heavy IoN Experiment (CSHINE). The fission fragments are measured by three large-area parallel plate avalanche counters, which can deliver the position and the arrival timing information of the fragments. The start timing information is given by the radio frequency of the cyclotron. Using the velocities of the two fission fragments, the fission events are reconstructed. The broadening of both the velocity distribution and the azimuthal difference of the fission fragments decrease with the folding angle, in accordance with the picture that fast fission occurs. The anisotropic angular distribution of the fission axis also reveals consistently the dynamic feature the fission events.

nucl-ex↗

arXiv2021

Electrostatically interacting Wannier qubits in curved space

Derivation of tight-binding model from Schroedinger formalism for various topologies of position-based semiconductor qubits is presented in this work in case of static and time-dependent electric fields. Simplistic tight-binding model allows for description of single-electron devices at large integration scale. The case of two electrostatically Wannier qubits (that are also known as position based qubits) in Schroedinger model is presented with omission spin degrees of freedom. The concept of programmable quantum matter can be implemented in the chain of coupled semiconductor quantum dots. Indeed highly integrated and developed cryogenic CMOS nanostructures can be mapped to coupled quantum dots, whose connectivity can be controlled by voltage applied across transistor gates as well as external magnetic field. Using anti-correlation principle arising from Coulomb repulsion interaction between electrons one can implement classical and quantum inverter (Classical/Quantum Swap gate) and many other logical gates. This anti-correlation will be weaken due to the fact of quantumness of physical process is bringing coexistence of correlation and anti-correlation at the same time. One of the central results presented in this work relies on the emergence of dissipation processes during smooth bending of semiconductor nanowires both in the case of classical and quantum picture. We observe strong localization of wave-packet due to nanowire bending. The obtained results can be mapped to problem of electron in curved space, so they can be expressed by programmable position-dependent metric embedded in Schroedinger equation. Indeed semiconductor quantum dot system is capable of mimicking the curved space what provides bridge between fundamental and applied science present in implementation of single-electron devices.

cond-mat.mes-hall↗