annotation    project goals    publications: 2017, 2018, 2019, 2020, 2021


Project title: Exotic quantum states of low-dimensional spin and electron systems

Principal investigator: Jozef Strečka

Grant Agency: Slovak Research and Development Agency

Project ID:  APVV-16-0186

Time schedule: 2017-2021

Participating organizations and team members:

  • Faculty of Science of Pavol Jozef Šafárik University in Košice
    • Jozef Strečka
    • Michal Jaščur
    • Milan Žukovič
    • Andrej Bobák
    • Tomáš Lučivjanský
    • Katarína Karľová
    • Olesia Krupnitska
    • Marek Semjan
    • Michal Rončík
    • Azadeh Ghannadan
  • Institute of Physics of Slovak Academy of Sciences in Bratislava
    • Andrej Gendiar
    • Ladislav Šamaj
    • Roman Krčmár
  • Institute of Experimental Physics of Slovak Academy of Sciences in Košice
    • Hana Čenčariková
    • Natália Tomašovičová
  • Faculty of Manufacturing Technologies of Technical University of Košice in Prešov
    • Lucia Gálisová

Annotation:

The project is devoted to theoretical study of low-dimensional quantum spin and electron systems, which will be examined by the combination of advanced analytical and numerical methods including among other matters exact mapping transformations, transfer-matrix method, strong-coupling approach, classical and quantum Monte
Carlo simulations, exact diagonalization and density-matrix renormalization group method. The obtained theoretical outcomes will contribute to a deeper understanding of exotic quantum states of spin and electron systems such as being for instance different kinds of quantum spin liquids as well as quantum states with a subtle long-range order of topological character or with a character of valence-bond solid. The project will significantly contribute to a clarification of unconventional magnetic behavior of selected low-dimensional magnetic materials and thus, it will have significant impact on a current state-of-the-art in the field of condensed matter physics and material science. On the other hand, a detailed investigation of quantum entanglement will establish borders of applicability of the studied spin and electron systems for the sake of quantum computation and quantum information processing. Another important outcome of the project is to clarify nontrivial symmetries in tensor states of the strongly correlated spin and electron systems affected by either position dependent interactions or changes in lattice geometries, which induce phase transitions of many types.

Project goals:

The general goal of the project is to provide a comprehensive understanding of several exotic quantum states of low-dimensional spin and electron systems, which will either find their application by an interpretation of known and yet unresolved experimental data of real magnetic materials or will contribute to a theoretical prediction of the novel
quantum states of matter. The particular goals of the project are:

  1. To find an exact analytical solution for the spin-1/2 Ising-Heisenberg orthogonal-dimer chain, which conforms with a magnetic structure of the polymeric coordination compound [Dy(hfac)2(CH3OH)]2[Cu(dmg)(Hdmg)]2. To examine possible dimerized states of the quantum spin chain and provide a theoretical explanation of the available experimental data.
  2. To provide an microscopic explanation of the quantum spin liquid and intermediate one-third plateau, which were experimentally detected in a magnetization process of the spin-chain compounds Cu3(P2O6OH)2 and Cu3(P2O6OD)2. To explore the magnetization process of the corresponding theoretical model, the trimerized
    Heisenberg chain, by the many-body perturbation theory developed from the monomer-dimer limit and the exactly solved trimerized Ising-Heisenberg chain. To compare the analytical results with the state-of-the-art numerical calculations, which will be obtained by making use of the quantum Monte Carlo simulations and/or density-matrix renormalization group method.
  3. To investigate quantum phase transitions of the spin-1/2 Ising-Heisenberg ladder, which will be driven by the external electric field directed along the axis of a spin ladder. To describe the magnetoelectric effect microscopically stemming from the inverse Dzyaloshinsky-Moriya interaction within the framework of exact mapping methods (rotational transformation, unitary transformation, Jordan-Wigner fermionization). To clarify the magnetic behavior of quantum ordered and disordered phases in a vicinity of quantum critical points.
  4. To reveal and rigorously describe the topological Haldane-type quantum states in a magnetization process of the Heisenberg octahedral chain by establishing a precise mapping correspondence with the effective Hamiltonian, which will be subsequently solved by the density-matrix renormalization group method and exact numerical diagonalization. To describe by exact means the unconventional quantum states and their phase boundaries in the highly frustrated region by combining the variational arguments with the concept of localized magnons. To quantify the quantum entanglement of the novel quantum states.
  5. To find the exact analytical solution for the branched Ising-Heisenberg spin chains, which conform with a magnetic structure of the heterobimetallic coordination compounds (Tp)2Fe2(CN)6(OAc)(bdmap)Cu2(H2O) and (Tp)2Fe2(CN)6(OAc)(bap)Cu2(MeOH). To investigate possible dimerized quantum states and clarify the available experimental data for the magnetization and susceptibility. To compare the obtained analytical results with the most advanced numerical calculations, which will be obtained for analogous XXZ Heisenberg spin chains using quantum Monte Carlo and/or density-matrix renormalization group methods.
  6. To investigate dimerized and trimerized quantum states of the Ising-Heisenberg model on geometrically frustrated triangles-in-triangles lattices in a magnetic field using exact mapping techniques in combination with the method of exact recursive relations and classical Monte Carlo simulations. To provide a qualitative explanation of the possible quantum states of the polymeric coordination compounds Cu9X2(cpa)6.
  7. To analyze various types of phase transitions and their universality classification for quantum and classical spin models on non-Euclidean lattice geometries by means of tensor renormalization group methods. The objective is to clarify the essence of locality and non-divergence of a correlation length at a phase transition upon application to the spin models on hyperbolic and fractal lattices.
  8. To explain the effect of a mutual interplay of chiral degrees of freedom and quantum spin ordering on thermodynamic properties of 2D Ising-Heisenberg systems with the elementary unit cell of trigonal bipyramids by performing exact analytical calculations. To describe the influence of macroscopic degeneracy associated with chiral degrees of freedom close to the continuous phase transitions. To examine the magnetic behavior in non-zero magnetic field by combining analytical approaches with classical Monte Carlo simulations.
  9. To develop a method synthetizing analytic t-expansions and a numerical algorithm Tensor Product Variational Formulation, which results in an improvement of the ground-state energy of two-dimensional quantum spin models, in particular, the Heisenberg, XY, and transverse-field Ising models.
  10. To clarify the quantum origin of fractional magnetization plateaux experimentally observed in the magnetization process SrCu2(BO3)2 within the many-body perturbation theory developed from the exactly solved Ising-Heisenberg model. To compare the obtained results with the most accurate numerical calculations.
  11. To find an exact solution for the 2D version of the coupled spin-electron system with the elementary unit cell of trigonal bipyramids. To examine the effect of doping on phase transitions and critical phenomena by generalizing the procedure developed in our previous studies. To examine the magnetic behavior in non-zero magnetic field by combining the mapping method with the corner transfer-matrix method and/or classical Monte Carlo simulations.
  12. To localize precisely the emergence of Majorana fermions (followed by generalized parafermions) in one- and two-dimensional quantum systems, where a spin-orbital coupling of paired electrons, Zeeman interaction of spin fermions under magnetic field imposed, and presence of the Coulomb interaction play important role. The model is studied in GaAs wires coupled to a superconducting layer.
  13. To propose and exactly solve a simplified version of spin-pseudospin model, which would allow a microscopic description of the mutual coexistence of spin and charge ordering in low-dimensional cuprates. To perform an extensive numerical analysis of the generalized version of the spin-pseudospin model, which cannot be solved by analytical methods.


Publications:


2017:

  1. L. Gálisová, Magnetization plateau as a result of the uniform and gradual electron doping in a coupled spin-electron double-tetrahedral chain, Phys. Rev. E 96 (2017) 052110. doi: 10.1103/PhysRevE.96.052110
  2. H. Ueda, K. Okunishi, R. Krčmár, A. Gendiar, S. Yunoki, T. Nishino, Critical behavior of the two-dimensional icosahedron model, Phys. Rev. E 96 (2017) 062112. doi: 10.1103/PhysRevE.96.062112
  3. O. Rojas, M. Rojas, S.M. de Souza, J. Torrico, J. Strečka, M.L. Lyra, Thermal entanglement  in a spin-1/2 Ising-XYZ distorted diamond chain with the second-neighbor interaction between nodal Ising spins, Physica A 486 (2017) 367-377. doi: 10.1016/j.physa.2017.05.099
  4. J. Genzor, T. Nishino, A. Gendiar, Tensor networks, Phase transition phenomena on hyperbolic and fractal geometries, Acta Phys. Slov. 67 (2017) 85-206. doi:


2018:

  1. K. Karľová, J. Strečka, M.L. Lyra, Unconventional quantum antiferromagnetism with a fourfold symmetry breaking in a spin-1/2 Ising-Heisenberg pentagonal chain, Phys. Rev. B 97 (2018) 104407. doi: 10.1103/PhysRevB.97.104407
  2. J. Strečka, K. Karľová, V. Baliha, O. Derzhko, Ising versus Potts criticality in low-temperature magnetothermodynamics of a frustrated spin-1/2 Heisenberg triangular bilayer, Phys. Rev. B 98 (2018) 174426. doi: 10.1103/PhysRevB.98.174426
  3. A. Bobák, E. Jurčišinová, M. Jurčišin, M. Žukovič, Frustrated spin-1/2 Ising antiferromagnet on a square lattice in a transverse field, Phys. Rev. E 97 (2018) 022124. doi: 10.1103/PhysRevE.97.022124
  4. R. Krčmár, L. Šamaj, Original electric-vertex formulation of the symmetric eight-vertex model on the square lattice is fully nonuniversal, Phys. Rev. E 97 (2018) 012108. doi: 10.1103/PhysRevE.97.012108
  5. M. Žukovič, G. Kalagov, Magnetic quasi-long-range ordering in nematic systems due to competition between higher-order couplings, Phys. Rev. E 97 (2018) 052101. doi: 10.1103/PhysRevE.97.052101
  6. J. Honkonen, T. Lučivjanský, V. Škultéty, Influence of turbulent mixing on critical behavior of directed percolation process: Effect of compressibility, Phys. Rev. E 97 (2018) 022123. doi: 10.1103/PhysRevE.97.022123
  7. R. Krčmár, J. Genzor, Y. Lee, H. Čenčariková, T. Nishino, A. Gendiar, Tensor-network study of quantum phase transition on Sierpiński fractal, Phys. Rev. E 98 (2018) 062114. doi: 10.1103/PhysRevE.98.062114
  8. H. Čenčariková, J. Strečka, Enhanced magnetoelectric effect of the exactly solved spin-electron model on a doubly decorated square lattice in the vicinity of a continuous phase transition, Phys. Rev. E 98 (2018) 062129 (7 strán). doi: 10.1103/PhysRevE.98.062129
  9. H. Čenčariková, J. Strečka, A. Gendiar, Magnetization processes and existence of reentrant phase transitions in coupled spin-electron model on doubly decorated planar lattices, J. Magn. Magn. Mater. 452 (2018) 512-521. doi: 10.1016/j.jmmm.2017.10.056
  10. M. Žukovič, M. Semjan, Magnetization process and magnetocaloric effect in geometrically frustrated Ising antiferromagnet and spin ice models on a ‘Star of David’ nanocluster, J. Magn. Magn. Mater. 451 (2018) 311-318. doi: 10.1016/j.jmmm.2017.11.076
  11. L. Gálisová, D. Knežo, Macroscopic ground-state degeneracy and magnetocaloric effect in the exactly solvable spin-1/2 Ising-Heisenberg double-tetrahedral chain, Phys. Lett. A 382 (2018) 2839-2845 (7 strán). doi: 10.1016/j.physleta.2018.06.012
  12. M. Žukovič, M. Borovský, A. Bobák, Thermodynamic and critical properties of an antiferromagnetically stacked triangular Ising antiferromagnet in a field, Phys. Lett. A 382 (2018) 1305-1311. doi: 10.1016/j.physleta.2018.03.026
  13. M. Žukovič, Multiple phase transitions in the XYmodel with nematic-like couplings, Phys. Lett. A 382 (2018) 2618-2621. doi: 10.1016/j.physleta.2018.07.039
  14. L. Gálisová, J. Strečka, Magnetic and magnetocaloric properties of the exactly solvable mixed-spin Ising model on a decorated triangular lattice in a magnetic field, Physica E 99 (2018) 244-253. doi: 10.1016/j.physe.2018.01.017
  15. K. Karľová, J. Strečka, Continuous field-driven phase transition from the Ising universality class of a frustrated spin-1/2 Heisenberg FM/AF square bilayer, Solid State Commun. 281 (2018) 31-37. doi: 10.1016/j.ssc.2018.06.014
  16. H. Čenčariková, J. Strečka, A. Gendiar, N. Tomašovičová, The influence of further-neighbor spin-spin interaction on a ground state of 2D coupled spin-electron model in a magnetic field, Physica B 536 (2018) 432-438. doi: 10.1016/j.physb.2017.10.029
  17. M.Hnatič, G.Kalagov, T. Lučivjanský, Scaling behavior in interacting systems: joint effect of anisotropy and compressibility, Eur. Phys. J. B  91 (2018) 269 (12 strán). doi: 1140/epjb/e2018-90308-1
  18. J. Strečka, Strong- and Weak-Universal Critical Behaviour of a Mixed-Spin Ising Model with Triplet Interactions on the Union Jack (Centered Square) Lattice, Entropy 20 (2018) 91. doi: 10.3390/e20020091
  19. J. Strečka, K. Karľová, Magnetization curves and low-temperature thermodynamics of two spin-1/2 Heisenberg edge-shared tetrahedra, AIP Adv. 8 (2018) 101403. doi: 10.1063/1.5042029
  20. M. Daniška, A. Gendiar, Study of classical and quantum phase transitions on non-Euclidean geometries in higher dimensions, Acta Phys. Slov. 68 (2018) 187-286. doi:


2019:

  1. L.M. Veríssimo, M.S.S. Pereira, J. Strečka, M.L. Lyra, Kosterlitz-Thouless and Gaussian criticalities in a mixed spin-(1/2, 5/2, 1/2) Heisenberg branched chain with exchange anisotropy, Phys. Rev. B 99 (2019) 134408 (9 strán). doi: 10.1103/PhysRevB.99.134408
  2. F. Souza, M.L. Lyra, J. Strečka, M.S.S. Pereira, Magnetization processes and quantum entanglement in a spin-1/2 Ising-Heisenberg chain model of a heterotrimetallic Fe-Mn-Cu coordination polymer, J. Magn. Magn. Mater. 471 (2019) 423-431 (9 strán). doi: 10.1016/j.jmmm.2018.09.121
  3. K. Karľová, J. Strečka, T. Verkholyak, Cluster-based Haldane phases, bound magnon crystals and quantum spin liquids of a mixedspin-1 and spin-1/2 Heisenberg octahedral chain, Phys. Rev. B 100 (2019) 094405 (12 strán). doi: 10.1103/PhysRevB.100.094405
  4. K. Karľová, J. Strečka, M.L. Lyra, Breakdown of intermediate one-half magnetization plateau of spin-1/2 Ising-Heisenberg and Heisenberg branched chains at triple and Kosterlitz-Thouless critical points, Phys. Rev. E 100 (2019) 042127 (12 strán). doi: 10.1103/PhysRevE.100.042127
  5. L. Lederová, A. Orendáčová, R. Tarasenko, K. Karľová, J. Strečka, A. Gendiar, M. Orendáč, A. Feher, Interplay of magnetic field and interlayer coupling in the quasi-two-dimensional quantum magnet Cu(en)Cl2: Realization of the spin-1/2 rectangular/zigzag square Heisenberg lattice, Phys. Rev. B 100 (2019) 134416 (17 strán). doi: 10.1103/PhysRevB.100.134416
  6. H. Čenčariková, J. Strečka, Conventional and rotating magnetoelectric effect of a half-filled spin-electron model on a doubly decorated square lattice, Phys. Lett. A 383 (2019) 125957 (5 strán). doi: 10.1016/j.physleta.2019.125957
  7. L. Gálisová, Frustration phenomenon in the spin-1/2 Ising-Heisenberg planar model of inter-connected trigonal bipyramid structures, J. Phys.: Condens. Matter 31 (2019) 465801 (9 strán). doi: 10.1088/1361-648X/ab37e3
  8. M. Žukovič, XY model with antinematic interaction, Phys. Rev. E 99 (2019) 062112 (10 strán). doi: 10.1103/PhysRevE.99.062112
  9. A. Bobák, E. Jurčišinová, M. Jurčišin, M. Žukovič, T. Balcerzak, An investigation of the J1-J2-J3 transverse Ising antiferromagnet on the honeycomb lattice with frustration, Physica A 518 (2019) 13-21 (9 strán). doi: 10.1016/j.physa.2018.11.058
  10. L. Šamaj and E. Trizac, Electric double layers with surface charge modulations: Exact Poisson-Boltzmann solutions, Phys. Rev. E 100 (2019) 042611 (17 strán). doi: 10.1103/PhysRevE.100.042611
  11. L. Šamaj, Short-Distance Symmetry of Pair Correlations in Two-Dimensional Jellium, J. Stat. Phys. (2019) 1 (18 strán). doi: 10.1007/s10955-019-02430-0
  12. V. Antonov, N. M. Gulitskiy, M. M. Kostenko, T. Lučivjanský, Passive advection of a vector field by compressible turbulent flow: renormalizations group analysis near d = 4, Universe 5 (2019) 37 (12 strán). doi:10.3390/universe5010037
  13. V. Antonov, N. M. Gulitskiy, M. M. Kostenko, T. Lučivjanský, Renormalization group analysis of models of advection of a vector a vector admixture and a tracer field by a compressible turbulent flow, Theor. Math. Phys. 200 (2019) 1294-1312 (19 strán). doi: 10.1134/S0040577919090046
  14. M. Hnatič, J. Honkonen, T. Lučivjanský, Symmetry breaking in stochastic dynamics and turbulence, Symmetry 11 (2019) 1193 (52 strán). doi:10.3390/sym11101193


2020:

  1. F. Souza, L.M. Veríssimo, J. Strečka, M.L. Lyra, M.S.S. Pereira, Exact and density matrix renormalization group studies of two mixed spin-(1/2, 5/2, 1/2) branched-chain models developed for a heterotrimetallic Fe-Mn-Cu coordination polymer, Physical Review B 102 (2020) 064414 (13 strán). doi: 10.1103/PhysRevB.102.064414
  2. H. Čenčariková, J. Strečka, A. Gendiar, Influence of applied electric and magnetic fields on a thermally-induced reentrance of a coupled spin-electron model on a decorated square lattice, Physica E 115 (2020) 113717 (8 strán). doi: 10.1016/j.physe.2019.113717
  3. M. Jaščur, M. Rončík, T. Balcerzak, K. Szałowski, A novel critical behavior of the spin-1 Blume–Capel model with a distance dependent nearest-neighbor exchange interaction and magneto-elastic coupling, Journal of Physics: Condensed Matter 32 (2020) 335801 (11 strán). doi: 10.1088/1361-648X/ab85f5
  4. J. Strečka, L. Gálisová, T. Verkholyak, Enhanced magnetoelectric effect near a field-driven zero-temperature quantum phase transition of the spin-1/2 Heisenberg-Ising ladder, Physical Review E 101 (2020) 012103 (5 strán). doi: 10.1103/PhysRevE.101.012103
  5. J. Strečka, C. Ekiz, Nature of intermediate magnetization plateaus of a spin-1/2 Ising-Heisenberg model on a triangulated Husimi lattice resembling a triangulated kagome lattice, Physical Review E 102 (2020) 012132 (11 strán). doi: 10.1103/PhysRevE.102.012132
  6. H. Ueda, K. Okunishi, K. Harada, R. Krčmár, A. Gendiar, S. Yunoki, T. Nishino, Finite-m scaling analysis of Berezinskii-Kosterlitz-Thouless phase transitions and entanglement spectrum for the six-state clock model, Physical Review E 101 (2020) 062111 (7 strán). doi: 10.1103/PhysRevE.101.062111
  7. E. Pospíšilová, R. Krčmár, A. Gendiar, L. Šamaj, Full nonuniversality of the symmetric 16-vertex model on the square lattice. Physical Review E 102 (2020) 012125 (8 strán).doi: 10.1103/PhysRevE.102.012125
  8. L. Šamaj, M. Trulsson, E. Trizac, Strong-coupling theory of counterions with hard cores between symmetrically charged walls, Physical Review E 102 (2020) 042604 (16 strán). doi: 10.1103/PhysRevE.102.042604
  9. M. Dančo, M. Hnatič, T. Lučivjanský, L. Mižišin, Renormalization group study of superfluid phase transition: Effect of compressibility, Physical Review E 102 (2020) 022118 (18 strán). doi: 10.1103/PhysRevE.102.022118
  10. M. Semjan, M. Žukovič, Absence of long-range order in a general spin-S kagome lattice Ising antiferromagnet, Physics Letters A 384 (2020) 126615 (5 strán). doi: 10.1016/j.physleta.2020.126615
  11. L. Gálisová, Bipartite entanglement in the spin-1/2 Ising-Heisenberg planar lattice constituted of identical trigonal bipyramidal plaquettes, Physics Letters A 384 (2020) 126629 (6 strán). doi: 10.1016/j.physleta.2020.126629
  12. J. Strečka, O. Krupnitska, J. Richter, Investigation of bipartite entanglement across the magnetization process of a highly frustrated spin-1/2 Heisenberg octahedral chain as a new paradigm of the localized-magnon approach, EPL 132 (2020) 30004 (6 strán). doi: 10.1209/0295-5075/132/30004
  13. M. Mohylna, M. Žukovič, Effect of single-ion anisotropy on magnetocaloric properties of frustrated spin-s Ising nanoclusters, Magnetochemistry 6 (2020) 56 (16 strán). doi:10.3390/magnetochemistry6040056
  14. Y. Sasagawa, H. Ueda, J. Genzor, A. Gendiar, T. Nishino, Entanglement Entropy on the Boundary of the Square-Lattice ±J Ising Model, Journal of the Physical Society of Japan 89 (2020) 114005 (4 strany). doi: 10.7566/JPSJ.89.114005
  15. C. Chatelain, A. Gendiar, Absence of logarithmic divergence of the entanglement entropies at the phase transitions of a 2D classical hard rod model, European Physical Journal B 93 (2020) 134 (15 strán). doi: 10.1140/epjb/e2020-10059-8
  16. L. Šamaj, Short-Distance Symmetry of Pair Correlations in Two-Dimensional Jellium, Journal of Statistical Physics 178 (2020) 247-264 (18 strán). doi: 10.1007/s10955-019-02430-0
  17. L. Šamaj, Attraction of Like-Charged Walls with Counterions Only: Exact Results for the 2D Cylinder Geometry, Journal of Statistical Physics 181 (2020) 1699-1729 (31 strán). doi: 10.1007/s10955-020-02642-9
  18. J. Strečka, L. Gálisová, T. Verkholyak, Insights into nature of a magnetization plateau of 3d-4f coordination polymer [Dy2Cu2]n from a spin-1/2 Ising-Heisenberg orthogonal-dimer chain, Condensed Matter Physics 23 (2020) 43708 (11 strán). doi: 10.5488/CMP.23.43708
  19. K. Karľová, J. Strečka, Interplay of bipartite entanglement between two geometrically inequivalent spin pairs of a spin-1/2 Heisenberg distorted tetrahedron, Acta Physica Polonica A 137 (2020) 595-597 (3 strany). doi: 10.12693/APhysPolA.137.595
  20. A. Bobák, T. Lučivjanský, M. Žukovič, Magnetism of the diluted Ising antiferromagnet in a magnetic field on the kagome lattice: single-spin cluster approximation, Acta Physica Polonica A 137 (2020) 628-630 (3 strany). doi: 10.12693/APhysPolA.137.628
  21. M. Semjan, M. Žukovič, Magnetocaloric properties of an Ising antiferromagnet on a kagome lattice, Acta Physica Polonica A 137 (2020) 622-624 (3 strany). doi: 10.12693/APhysPolA.137.622
  22. L. Gálisová, Pairwise entanglement in double-tetrahedral chain with different Landé g-factors of the Ising and Heisenberg spins, Acta Physica Polonica A 137 (2020) 604 (3 strany). doi: 10.12693/APhysPolA.137.604
  23. H. Čenčariková, N. Tomašovičová, Comparative study of a critical behavior of a coupled spin-electron model on a doubly decorated square lattice in the canonical and grand-canonical ensemble, Acta Physica Polonica A 137 (2020) 607-609 (3 strany). doi: 10.12693/APhysPolA.137.607
  24. C. Ekiz, J. Strečka, Unsaturated bipartite entanglement of a spin-1/2 Ising–Heisenberg model on a triangulated Husimi lattice, Acta Physica Polonica A 137 (2020) 592-594 (3 strany). doi: 10.12693/APhysPolA.137.592
  25. A. Gendiar, Area-law study of quantum spin system on hyperbolic lattice geometries, Acta Physica Polonica A 137 (2020) 589-591 (3 strany). doi: 10.12693/APhysPolA.137.589
  26. R. Krčmár, A. Gendiar, T. Nishino, Entanglement-Entropy Study of Phase Transitions in Six-State Clock Model, Acta Physica Polonica A 137 (2020) 598-600 (3 strany). doi: 10.12693/APhysPolA.137.598


2021:

  1. L. Gálisová, J. Strečka, T. Verkholyak, S. Havadej, Magnetization plateaus and bipartite entanglement of an exactly solved spin-1/2 Ising-Heisenberg orthogonal-dimer chain, Physica E 125 (2021) 114089 (9 strán).
  2. H. Čenčariková, J. Strečka, Rotating magnetoelectric effect in a ground state of a coupled spin-electron model on a doubly decorated square lattice, Physica A 566 (2021) 125673 (8 strán).