Autor: Czart, W. R. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Superconducting Characteristics of the Penson-Kolb Model
Autorzy:: Czart, W. R.
Robaszkiewicz, S.
Powiązania:: https://bibliotekanauki.pl/articles/2012898.pdf
Data publikacji:: 2000-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.20.-z
71.28.+d
74.25.Ha
Opis:: We study superconducting properties of the Penson-Kolb model, i.e. the tight-binding model with the pair-hopping (intersite charge exchange) interaction J. The evolution of the critical fields, the coherence length, the Ginzburg ratio, and the London penetration depth with particle concentration n and pairing strength are determined. The results are compared with those found earlier for the attractive Hubbard model.
Źródło:: Acta Physica Polonica A; 2000, 97, 1; 217-220
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Influence of Coulomb Interactions on the Properties of Induced Pairing Model
Autorzy:: Czart, W. R.
Robaszkiewicz, St.
Powiązania:: https://bibliotekanauki.pl/articles/2027440.pdf
Data publikacji:: 2001-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.20.-z
74.20.Mn
71.28.+d
74.25.Ha
Opis:: We study the superconducting properties of a model of coexisting itinerant carriers and local pairs with finite binding energy, taking into account the effects of Coulomb (density-density) and direct pair hopping interactions. The evolution of the phase diagrams and superfluid characteristics with electron concentration, interaction parameters and the relative position of the bands is examined. The model is found to exhibit several kinds of superconducting behaviors ranging from the BCS-like to the local-pair-like. The relevance of the obtained results to the interpretation of experimental data for the doped bismuthates (Ba$\text{}_{1-x}$K$\text{}_{x}$BiO$\text{}_{3}$ and BaPb$\text{}_{1-x}$BiO$\text{}_{3}$) is pointed out.
Źródło:: Acta Physica Polonica A; 2001, 100, 1; 75-88
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Superconducting Properties of theη-Pairing State in the Penson-Kolb-Hubbard Model
Autorzy:: Czart, W. R.
Robaszkiewicz, S.
Powiązania:: https://bibliotekanauki.pl/articles/2041460.pdf
Data publikacji:: 2004-11
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.20.-z
71.28.+d
74.25.Ha
Opis:: The Penson-Kolb-Hubbard model, i.e. the Hubbard model with the pair-hopping interaction J is studied. We focus on the properties of the superconducting state with the Cooper-pair center-of-mass momentum q= Q (η-phase). The transition into theη-phase, which is favorized by the repulsive J (J<0) is found to occur only above some critical value |J$\text{}_{c}$|, dependent on band filling, on-site interaction U and band structure, and the system never exhibits standard BCS-like features. This is in obvious contrast with the properties of the isotropic s-wave state, stabilized by the attractive J and attractive U, which exhibit at T=0 a smooth crossover from the BCS-like limit to that of tightly bound pairs with increasing pairing strength.
Źródło:: Acta Physica Polonica A; 2004, 106, 5; 709-713
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Superconductivity of the Two-Dimensional Penson-Kolb Model
Autorzy:: Czart, W. R.
Robaszkiewicz, S.
Powiązania:: https://bibliotekanauki.pl/articles/2029270.pdf
Data publikacji:: 2001-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.20.-z
71.28.+d
74.25.Ha
Opis:: Two-dimensional (d=2) Penson-Kolb model, i.e. the tight-binding model with the pair-hopping (intersite charge exchange) interaction, is considered and the effects of phase fluctuations on the s-wave superconductivity of this system are discussed within the Kosterlitz-Thouless scenario. The London penetration depth λ at T=0, the Kosterlitz-Thouless critical temperature T$\text{}_{c}$, and the Hartree-Fock approximation critical temperature T$\text{}_{p}$ are determined as a function of particle concentration and interaction. The Uemura type plots (T$\text{}_{c}$ vs.λ$\text{}^{-2}$(0)) are derived. Beyond weak coupling and for low concentrations they show the existence of universal scaling: T$\text{}_{c}$ ~1/λ$\text{}^{2}$(0), as it was previously found for the attractive Hubbard model and for the models with intersite electron pairing.
Źródło:: Acta Physica Polonica A; 2001, 100, 6; 885-895
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Electron Orderings of Half-Filled Extended Hubbard Models with Spin- and Charge-Exchange Interaction
Autorzy:: Czart, W. R.
Robaszkiewicz, S.
Powiązania:: https://bibliotekanauki.pl/articles/2046752.pdf
Data publikacji:: 2006-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.10.Fd
75.10.-b
75.30.Gw
71.45.Lr
74.20.-z
Opis:: The electron orderings of the half-filled extended Hubbard models (i) with anisotropic spin-exchange interactions (the t-U-J$\text{}_{ǁ}$-J$\text{}_{⊥}$ model) and (ii) with charge-exchange interaction (the t-U-I model) are discussed. In particular, we present new results concerning the phase diagrams of the model (i) in the case of uniaxial spin exchange (J$\text{}_{ǁ}$≢0) for d-dimensional hypercubic lattices (1≤d≤∞) and conclude about the basic effects of the particular spin- and charge-exchange interaction terms (J$\text{}_{ǁ}$, J$\text{}_{⊥}$, and I) in both models.
Źródło:: Acta Physica Polonica A; 2006, 109, 4-5; 577-582
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 6.

Tytuł:: Superfluid Characteristics of Induced-Pairing Model
Autorzy:: Czart, W. R.
Szkudlarek, M.
Robaszkiewicz, S.
Powiązania:: https://bibliotekanauki.pl/articles/1955834.pdf
Data publikacji:: 1997-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.28.+d
74.25.Ha
74.20.-z
Opis:: We study the electromagnetic and thermodynamic properties of a model of coexisting local electron pairs and itinerant carriers coupled via the intersubsystem charge exchange. The calculations of the London penetration depth, the energy gap, the magnetic critical fields and the coherence length in the superconducting phase are performed. The effects of reduced binding energy of local pairs are discussed.
Źródło:: Acta Physica Polonica A; 1997, 91, 2; 415-418
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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