Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "71.10.+w" wg kryterium: Temat


Tytuł:
Time-Reversal Invariant Topological Superconductivity in Quasi-One-Dimensional Structures
Autorzy:
Mammadova, S.
Nakhmedov, E.
Alekperov, O.
Powiązania:
https://bibliotekanauki.pl/articles/1398788.pdf
Data publikacji:
2016-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.78.-w
71.10.Pm
71.70.Ej
74.50.+r
Opis:
It is shown that a time-reversal invariant topological superconductivity can be realized in a quasi-one-dimensional structure, which is fabricated by filling the superconducting materials into the periodic channel of dielectric matrices like zeolite and asbestos under high pressure. The topological superconducting phase sets up in the presence of large spin-orbit interactions when s-wave intra-wire and d-wave inter-wire pairings take place. Kramers pairs of Majorana bound states emerge at the edges of each wire. The time-reversal topological superconductor belongs to DIII class of symmetry with a Z₂ invariant.
Źródło:
Acta Physica Polonica A; 2016, 129, 4; 800-802
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
DFT Estimation of Exchange Coupling Constant of Cr₈ Molecular Ring using the Hybrid Functional B3LYP
Autorzy:
Wojciechowski, M.
Brzostowski, B.
Kamieniarz, G.
Powiązania:
https://bibliotekanauki.pl/articles/1386209.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Xx
71.15.Mb
73.22.-f
75.30.Et
31.15.E-
71.10.-w
Opis:
A study of electronic and magnetic properties of an octametallic chromium-based homonuclear molecule Cr₈F₈(CO₂-C(CH₃)₃)₁₆ is presented, using density functional theory (DFT) approach and linearized augmented plane wave (LAPW) method with Perdew, Burke and Ernzerhof (PBE) and Becke 3-term correlation (B3LYP) functionals. The exchange coupling parameters between transition metals ions are extracted, taking into account two different (ferro- and antiferromagnetic) spin configurations. The value J=3.1 meV found for the hybrid B3LYP functional improves significantly the one obtained for the PBE functional and gives an evidence for the superiority of the former in simulation of molecular nanomgnets. Moreover, the hybrid functional yields excellent spin density localisation, an enhancement of the HOMO-LUMO gaps and the value 2.81 $μ_B$ of magnetic moment at the chromium centre in good agreement with experiment.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 407-409
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mapping of the DFT Spin Configuration Energies of Cr8Cd Molecular Ring onto the Energy Structure of Falicov-Kimball Model
Autorzy:
Wojciechowski, M.
Brzostowski, B.
Lemański, R.
Kamieniarz, G.
Powiązania:
https://bibliotekanauki.pl/articles/1386266.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.50.Xx
71.15.Mb
73.22.-f
75.30.Et
31.15.E-
71.10.-w
Opis:
A comprehensive study of electronic and magnetic properties of a recently synthesized nonametalic chromium-based heteronuclear molecule Cr₈CdF₉(O₂C-C(CH₃)₃)₁₈ is presented, using DFT and Falicov-Kimball (FK) model approach. The magnetic moments are calculated and the spin charge density map is discussed. The exchange coupling parameters between transition metals ions are extracted, taking into account all the nonequivalent spin configurations. It is demonstrated that the energies of the spin configurations can be reproduced by the FK model with a set of parameters consistent with that for the parent Cr8 molecule. For molecular ring considered, the ground state corresponds to the antiferromagnetic configuration and the ferromagnetic configuration yields the highest energy.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 410-412
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Exact Results for the Zero-Bandwidth Extended Hubbard Model with Intersite Charge and Magnetic Interactions
Autorzy:
Kapcia, K.
Kłobus, W.
Robaszkiewicz, S.
Powiązania:
https://bibliotekanauki.pl/articles/1385252.pdf
Data publikacji:
2015-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
71.10.-w
71.10.Hf
71.45.Lr
75.30.Fv
Opis:
The extended Hubbard model in the zero-bandwidth limit is studied. The effective Hamiltonian consists of (i) on-site U interaction, (ii) intersite density-density interaction W, and (iii) Ising-like magnetic exchange interaction J between the nearest-neighbors. We present rigorous (and analytical) results obtained within the transfer-matrix method for 1D chain in two particular cases: (a) W=0 and n=1; (b) U → +∞ and n=1/2 (W ≠ 0, J ≠ 0). We obtain the exact formulae for the partition functions which enables to calculate thermodynamic properties such as entropy, specific heat (c), and double occupancy per site. In both cases the system exhibits an interesting temperature dependence of c involving a characteristic two-peak structure. There are no phase transitions at finite temperatures and the only transitions occur in the ground state.
Źródło:
Acta Physica Polonica A; 2015, 127, 2; 284-286
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fundamental Gaps in $Cr_{8}$, $Cr_{7}Ni$ and $Cr_{7}Cd$ Molecules
Autorzy:
Brzostowski, B.
Wojciechowski, M.
Kamieniarz, G.
Powiązania:
https://bibliotekanauki.pl/articles/1368520.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.Mb
31.15.E-
71.10.-w
Opis:
In this paper we investigate fundamental gaps of three octametallic Cr-based molecular rings $Cr_{8}F_{8}(Piv)_{16}$, $Cr_{7}NiF_{8}(Piv)_{16}$ and $Cr_{7}CdF_{8}(Piv)_{16}$ using the SIESTA package. We find that for the ground-state antiferromagnetic configurations, the gap of the homometallic ring is significantly higher than those of the heterometallic rings. In addition, the HOMO and LUMO orbitals are plotted and discussed.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 234-235
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heavy Quasiparticles in Yb Compounds: The Renormalized Band Approach
Autorzy:
Zwicknagl, G.
Powiązania:
https://bibliotekanauki.pl/articles/1368787.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.+w
71.10.Hf
71.27.+a
75.30.Mb
Opis:
Results for the magnetic-field-induced changes of the heavy quasiparticles in $YbRh_{2}Si_{2}$ are presented. The bands are determined by means of the Renormalized Band method. The progressive de-renormalization of the quasiparticles in the magnetic field, as well as the many-body enhancement of the Zeeman splitting are accounted for, using field-dependent quasiparticle parameters deduced from Numerical Renormalization Group studies.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 286-287
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dark States and Transport through Quantum Dots
Autorzy:
Tooski, S.
Bułka, B.
Powiązania:
https://bibliotekanauki.pl/articles/1428598.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.-w
33.57.+c
73.23.-b
73.63.Kv
Opis:
We consider current through triple and quadruple quantum dot systems in an in-plane electric field and in the sequential tunneling regime. The electric field breaks symmetry of the system and can trap electron in a dark state in which current flow can completely be blocked. Consequently rotating the electric field, one can observe current oscillations and blockades due to dark state.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1231-1233
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Novel Excitation-Density Dependence in Strongly Spin-Charge Coupled System
Autorzy:
Ohara, J.
Kanamori, Y.
Ishihara, S.
Powiązania:
https://bibliotekanauki.pl/articles/1490003.pdf
Data publikacji:
2012-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.30.+h
71.10.-w
78.47.J-
78.20.Bh
Opis:
Photoinduced spin-charge dynamics in strongly correlated electron systems is studied based on an extended double-exchange model. Solving a time-dependent Schrödinger equation with the Lanczos method, we trace the process of photoinduced melting of an antiferromagnetic charge order and analyze the excitation-density dependence on that. In the case of low density photoexcitation, both charge and spin orders are melted by photocarrier doping. This is interpreted with a conventional double-exchange mechanism. In the case of high density photoexcitation, however, the charge order is melted. The antiferromagnetic spin order is transiently weakened but after turnoff of the photoirradiation it recovers. This phenomenon strikingly differs from the weak photoexcitation case.
Źródło:
Acta Physica Polonica A; 2012, 121, 2; 355-358
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Singlet-Triplet Switching Induced by Electric Field in Triple Quantum Dots
Autorzy:
Łuczak, J.
Bułka, B.
Powiązania:
https://bibliotekanauki.pl/articles/1427582.pdf
Data publikacji:
2012-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.-w
33.57.+c
73.23.-b
73.63.Kv
Opis:
We analyze influence of an external electric field on magnetic properties of a triple quantum dot system in a triangular and linear geometry. The system contains four electrons and is described by an extended Hubbard model which includes electron correlations and exchange processes. The electric field leads to splitting of energy levels (the Stark effect) and to transition between the singlet and triplet states.
Źródło:
Acta Physica Polonica A; 2012, 121, 5-6; 1195-1197
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some Properties of the Model of a~Superconductor with Pair Hopping and Magnetic Interactions at Half-Filling
Autorzy:
Kapcia, K.
Powiązania:
https://bibliotekanauki.pl/articles/1431185.pdf
Data publikacji:
2012-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
71.10.-w
74.20.-z
74.81.-g
75.30.Fv
Opis:
We present our preliminary studies of an effective model of a superconductor with short coherence length involving magnetic interactions. The Hamiltonian considered consists of (i) the effective on-site interaction U, (ii) the intersite magnetic exchange interactions ($J^z,$ $J^{xy}$) between nearest-neighbors and (iii) the intersite charge exchange term I, determining the hopping of electron pairs between nearest-neighbor sites. In the analysis of the phase diagrams and thermodynamic properties of this model for half-filling (n=1) we have adopted the variational approach, which treats the on-site interaction term exactly and the intersite interactions within the mean-field approximation. One finds that the system considered can exhibit very interesting multicritical behaviors (including tricritical, critical-end and bicritical points) caused by the competition between magnetism and superconductivity, even for n=1. Our investigations show that, depending on the values of interaction parameters, the system at half-filling can exhibit three homogeneous phases: superconducting (SS), (anti-)ferromagnetic (F) and nonordered (NO). The transitions between ordered phases (SS, F) and the NO phase can be first order as well as second order ones, whereas SS-F transition is first order one. Temperature dependencies of the order parameters and thermodynamic properties of the system at the sequence of transitions: SS→F→NO with increasing temperature for J/I=0.3, U/I_0 = 0.69 and n=1 are also presented.
Źródło:
Acta Physica Polonica A; 2012, 121, 4; 733-737
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Unitary Transformation and Spectrum of a Three-Electron Quantum Dot
Autorzy:
Hassanabadi, H.
Rahimov, H.
Ghasem, H.
Powiązania:
https://bibliotekanauki.pl/articles/1493664.pdf
Data publikacji:
2011-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.21.La
73.20.Qt
71.10.-w
Opis:
We consider the Hamiltonian of a three-electron quantum dot composed of parabolic confinement plus the Coulomb terms. Instead of using the Jacobi coordinates, we apply a unitary transformation to this system. To avoid the complexity, the Taylor expansion of the effective potential is introduced into the problem and thereby a solution is found for the eigenvalues of the corresponding three-body Schrödinger equation in terms of the Wigner parameter.
Źródło:
Acta Physica Polonica A; 2011, 120, 3; 521-524
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electron Spectral Functions in the Presence of the Antiferromagnetic Order in the Two-Dimensional Hubbard Model
Autorzy:
Zaleski, T.
Kopeć, T.
Powiązania:
https://bibliotekanauki.pl/articles/1536615.pdf
Data publikacji:
2010-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
71.10.-w
71.10.Pm
Opis:
We use a recently proposed quantum SU(2)×U(1) rotor approach for the Hubbard model to calculate electronic spectral functions in a presence of an antiferromagnetic state for any value of the Coulomb interaction. We isolate the collective variables for charge and spin in the form of the space-time fluctuating U(1) phase field and SU(2) rotating spin quantization axis, respectively. As a result, the fermion Green function in the space-time domain becomes a product of a $CP^1$ propagator resulting from the SU(2) gauge fields, U(1) phase propagator and the pseudo-fermion correlation function. In turn, the spectral lines are obtained by performing the convolution of spin, charge and pseudo-fermion Green's functions. We observe an emergence of a sharp peak in the electron spectral functions within the antiferromagnetic phase, whose spectral weight is equal to the antiferromagnetic order parameter.
Źródło:
Acta Physica Polonica A; 2010, 118, 2; 267-272
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetic Properties of the Hubbard Model on Kagome Stripes
Autorzy:
Derzhko, O.
Maksymenko, M.
Richter, J.
Honecker, A.
Moessner, R.
Powiązania:
https://bibliotekanauki.pl/articles/1506953.pdf
Data publikacji:
2010-11
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.-w
Opis:
We consider the one-orbital N-site repulsive Hubbard model on two kagome like chains, both of which yield a completely dispersionless (flat) one-electron band. Using exact many-electron ground states in the subspaces with n ≤ $n_\text{max}$ ($n_\text{max}$ ∝ N) electrons, we calculate the square of the total spin in the ground state to discuss magnetic properties of the models. We have found that although for n < n_{max} the ground states contain fully polarized states, there is no finite region of electron densities n/$\mathcal{N}$ < 1 ($\mathcal{N}$ = N/3 or $\mathcal {N}$ = N/5) where ground-state ferromagnetism survives for $\mathcal {N}$ → ∞.
Źródło:
Acta Physica Polonica A; 2010, 118, 5; 736-737
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anomalous Self-Energy Features in the 2D Hubbard Model
Autorzy:
Avella, A.
Mancini, F.
Powiązania:
https://bibliotekanauki.pl/articles/1813757.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.Fd
71.27.+a
71.10.-w
Opis:
The electronic self-energy of the two-dimensional Hubbard model, computed in the non-crossing approximation within the composite operator method, is studied as a function of frequency as well as temperature at the Fermi surface, for a value of doping at which the pseudogap is already well developed. For values of momentum belonging to the phantom arc of the Fermi surface, both dependences show anomalous power law behavior in contrast to that expected from the Fermi liquid theory.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 395-398
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entanglement Properties and Phase Diagram of the Two-Orbital Atomic Hubbard Model
Autorzy:
Avella, A.
Mancini, F.
Scelza, G.
Chaturvedi, S.
Powiązania:
https://bibliotekanauki.pl/articles/1813770.pdf
Data publikacji:
2008-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.10.-w
71.10.Fd
71.27.+a
Opis:
We study the two-orbital Hubbard model in the limit of vanishing kinetic energy. The phase diagram in the V-J plane, with V and J denoting the interorbital hybridization and exchange coupling respectively, at half filling is obtained. A singlet(dimer)-triplet transition is found for a critical value of the ratio V/J. The entropy of formation, both in the mode and in the particle pictures, presents a jump at the same critical line in conformity with the suggested relation between criticality and entanglement.
Źródło:
Acta Physica Polonica A; 2008, 113, 1; 417-420
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies