41 citations · 632 across the 55 of their papers we have counts for
56 papers
Charge order on a triangular lattice with Mott physics and arbitrary charge density
Aleksey Alekseev, Agnieszka Cichy, Konrad Jerzy Kapcia
Triangular-lattice systems attract a lot of attention due to various frustration-induced and strongly correlated effects. Here, we focus on the charge-ordering phenomenon by means…
Phase structure of the one-dimensional lattice gauge theory with second nearest-neighbor interactions
Yeimer Zambrano, Aleksey Alekseev, Konrad J. Kapcia +2
We investigate the ground-state phase diagram of a one-dimensional lattice gauge theory (LGT) model with hard-core bosons at half-filling, extending previous studies…
Charge-Ordered States and the Phase Diagram of the Extended Hubbard Model on the Bethe lattice
Aleksey Alekseev, Konrad Jerzy Kapcia
We study the extended Hubbard model (EHM) with both onsite Hubbard interaction and the intersite density-density interaction between nearest-neighbors using the standard Hartree me…
Particle-Hole Asymmetry and Pinball Liquid in a Triangular-Lattice Extended Hubbard Model within Mean-Field Approximation
Aleksey Alekseev, Agnieszka Cichy, Konrad Jerzy Kapcia
Recently, triangular lattice models have received a lot of attention since they can describe a number of strongly-correlated materials that exhibit superconductivity and various ma…
Localized fermions on the triangular lattice with Ising-like interactions
Lubomíra Regeciová, Konrad Jerzy Kapcia
The model of localized fermions on the triangular lattice is analyzed in means of the Monte Carlo simulations in the grand canonical ensemble. The Hamiltonian of the system has a f…
Electronic properties and surface states of CeRhAs
Konrad Jerzy Kapcia, Andrzej Ptok
Locally noncentrosymmetric CeRhAs exhibits characteristic two-phase unconventional -- superconducting phase diagram. The transition from even- to odd-parity super…
Interplay of thermal and non-thermal effects in x-ray-induced ultrafast melting
Ichiro Inoue, Victor Tkachenko, Yuya Kubota +15
X-ray laser-induced structural changes in silicon undergoing femtosecond melting have been investigated by using an x-ray pump-x-ray probe technique. The experimental results for d…
Spin-polarized superconducting phase in semiconducting system with next-nearest-neighbor hopping on the honeycomb lattice
Agnieszka Cichy, Konrad J. Kapcia, Andrzej Ptok
The particles in the honeycomb lattice with on-site -wave pairing exhibit many interesting behaviors, which can be described in the framework of the Hubbard model. Among others,…
Magnetic and charge orders on the triangular lattice: Extended Hubbard model with intersite Ising-like magnetic interactions in the atomic limit
Konrad Jerzy Kapcia, Jan Barański
In the work, we investigated a generalized model of the fermionic lattice gas in the form of the extended Hubbard model with intersite Ising-like interactions (both antiferromagnet…
Continuous unitary transformation approach to the Kondo-Majorana interplay
Jan Baranski, Magdalena Baranska, Tomasz Zienkiewicz +2
We analyze a setup composed of a correlated quantum dot (QD) coupled to one metallic lead and one end of topological chain hosting a Majorana zero mode (MZM). In such a hybrid stru…
Electrical polarization switching in bulk single crystal GaFeO
Maria Biernacka, Paweł Butkiewicz, Konrad J. Kapcia +5
The electrical polarization switching on stoichiometric GaFeO single crystal was measured, and a new model of atomic displacements responsible for the polarization reverse wa…
Ultrafast demagnetization in bulk nickel induced by X-ray photons tuned to Ni and absorption edges
Konrad J. Kapcia, Victor Tkachenko, Flavio Capotondi +4
Studies of light-induced demagnetization started with the experiment performed by Beaupaire et al. on nickel. Here, we present theoretical predictions for X-ray induced demagnetiza…
Femtosecond reduction of atomic scattering factors triggered by intense x-ray pulse
Ichiro Inoue, Jumpei Yamada, Konrad J. Kapcia +12
X-ray diffraction of silicon irradiated with tightly focused femtosecond x-ray pulses (photon energy: 11.5 keV, pulse duration: 6 fs) was measured at various x-ray intensities up t…
Stress-Tuned Optical Transitions in Layered 1T-MX2 (M= Hf, Zr, Sn; X= S, Se) Crystals
Miłosz Rybak, Tomasz Woźniak, Magdalena Birowska +5
Optical measurements under externally applied stresses allow us to study the materials' electronic structure by comparing the pressure evolution of optical peaks obtained from expe…
Quench dynamics of Fano-like resonances in the presence of the on-dot superconducting pairing
Jan Baranski, Magdalena Baranska, Tomasz Zienkiewicz +1
We explore the electron dynamics of a system composed of double quantum dot embedded between metallic and superconducting leads in a T-shape geometry. In nanoscopic systems, where…
Electronic processes occurring during ultrafast demagnetization of cobalt triggered by X-ray photons tuned to Co L resonance
Konrad J. Kapcia, Victor Tkachenko, Flavio Capotondi +6
Magnetization dynamics triggered with ultrashort laser pulses has been attracting significant attention, with strong focus on the dynamics excited by VIS/NIR pulses. Only recently,…
Chiral phonons in binary compounds Bi ( = K, Rb, Cs) with P2/c structure
Jakub Skórka, Konrad J. Kapcia, Paweł T. Jochym +1
Binary compounds Bi ( = K, Rb, Cs) crystallize in P2/c structure containing both clockwise and anticlockwise chiral chains of Bi atoms. Electronic band structure exhibits…
Modeling of ultrafast X-ray induced magnetization dynamics in magnetic multilayer systems
K. J. Kapcia, V. Tkachenko, F. Capotondi +6
In this work, we report on modelling results obtained with our recently developed simulation tool enabling nanoscopic description of electronic processes in X-ray irradiated ferrom…
Connection between the semiconductor--superconductor transition and the spin-polarized superconducting phase in the honeycomb lattice
Agnieszka Cichy, Konrad Jerzy Kapcia, Andrzej Ptok
The band structure of noninteracting fermions in the honeycomb lattice exhibits the Dirac cones at the corners of the Brillouin zone. As a consequence, fermions in this lattice man…
Delayed onset and directionality of x-ray-induced atomic displacements observed on subatomic length scales
Ichiro Inoue, Victor Tkachenko, Konrad J. Kapcia +6
Transient structural changes of AlO on subatomic length scales following irradiation with an intense x-ray laser pulse (photon energy: 8.70 keV; pulse duration: 6 fs; fluen…
Charge-order on the triangular lattice: Effects of next-nearest-neighbor attraction in finite temperatures
Konrad Jerzy Kapcia
The extended Hubbard model in the atomic limit, which is equivalent to lattice fermionic gas, is considered on the triangular lattice. The model includes onsite Hubbard …
Thermodynamic and electromagnetic properties of the eta-pairing superconductivity in the Penson-Kolb model
Wojciech R. Czart, Konrad J. Kapcia, Roman Micnas +1
In the paper, we study the thermodynamic and electromagnetic properties of the Penson-Kolb (PK) model, i.e., the tight-binding model for fermionic particles with the pair-hopping i…
Charge-Order on the Triangular Lattice: A Mean-Field Study for the Lattice Fermionic Gas
Konrad Jerzy Kapcia
The adsorbed atoms exhibit tendency to occupy a triangular lattice formed by periodic potential of the underlying crystal surface. Such a lattice is formed by, e.g., a single layer…
Electronic and dynamical properties of CeRhAs: Role of RhAs layers and expected hidden orbital order
Andrzej Ptok, Konrad J. Kapcia, Paweł T. Jochym +3
Recently discovered heavy fermion CeRhAs compound crystallizes in the nonsymmorphic symmetry, which enables the occurrence of topological protection. Experimen…