Autor: Kujawa, A - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: The BCS-BEC Crossover and Superconductivity in a Lattice Fermion Model with Hard Core Repulsion
Autorzy:: Kujawa, A.
Powiązania:: https://bibliotekanauki.pl/articles/2047337.pdf
Data publikacji:: 2007-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.10.Fd
74.20.Rp
71.27.+a
71.10.Hf
Opis:: We considered the BCS-BEC crossover at T=0 in the framework of a lattice fermion model (the extended Hubbard model). We analyzed the case of on-site hard core repulsion (U=∞) and intersite attraction (W<0) in a 3D system with extended s-wave pairing symmetry. The mechanisms of density-driven and attraction-strength-driven crossover were analyzed. We obtained the ground state phase diagram. The analyzed quantities are: chemical potential, order parameter, coherence length, and fraction of condensed particles.
Źródło:: Acta Physica Polonica A; 2007, 111, 5; 745-752
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: On the Phase Diagram of Spin-Polarized Attractive Hubbard Model: Weak Coupling Limit
Autorzy:: Kujawa, A.
Micnas, R.
Powiązania:: https://bibliotekanauki.pl/articles/1812269.pdf
Data publikacji:: 2008-07
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.10.Fd
74.20.Rp
71.27.+a
71.10.Hf
Opis:: The superfluid properties of the attractive Hubbard model in a Zeeman magnetic field, and in the weak coupling regime were investigated. The temperature and magnetic field dependences of the order parameter were analyzed. Furthermore, the temperature vs. magnetic field and temperature vs. spin polarization phase diagrams for the 2D and 3D lattices were obtained. For some parameters a reentrant transition was found.
Źródło:: Acta Physica Polonica A; 2008, 114, 1; 43-50
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Some Properties of the Spin-Polarized Attractive Hubbard Model
Autorzy:: Kujawa, A.
Micnas, R.
Powiązania:: https://bibliotekanauki.pl/articles/1810407.pdf
Data publikacji:: 2009-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.10.Fd
74.20.Rp
71.27.+a
71.10.Hf
Opis:: The influence of a Zeeman magnetic field on the superconducting characteristics of the attractive Hubbard model was investigated. The ground state and temperature phase diagrams were obtained for a fixed number of particles. Two critical magnetic fields were found for the first order phase transition from the superconducting to the normal state for n ≠ 1. For some range of parameters a reentrant transition was found and gapless superconductivity was obtained. The significance of the Hartree term was also analyzed.
Źródło:: Acta Physica Polonica A; 2009, 115, 1; 138-140
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: On the BCS-BEC Crossover in the Spin-Polarized Attractive Hubbard Model at T=0
Autorzy:: Kujawa-Cichy, A.
Powiązania:: https://bibliotekanauki.pl/articles/1537284.pdf
Data publikacji:: 2010-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.10.Fd
74.20.Rp
71.27.+a
71.10.Hf
Opis:: The influence of the Zeeman magnetic field (h) on the ground state evolution of superfluid properties from the weak coupling (BCS-like) to the strong coupling limit of tightly bound local pairs with increasing attraction has been studied. The analysis was carried out within the spin-polarized attractive Hubbard model, for a fixed number of particles and a d = 3 simple cubic lattice. The broken symmetry Hartree approximation was used. For strong attraction and in the dilute limit, the homogeneous magnetized superconducting phase $(SC_{M})$ was found in the h-|U| and P-|U| diagrams.
Źródło:: Acta Physica Polonica A; 2010, 118, 2; 423-425
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: On the BCS-BEC Crossover in the 2D Asymmetric Attractive Hubbard Model
Autorzy:: Kujawa-Cichy, A.
Powiązania:: https://bibliotekanauki.pl/articles/1426931.pdf
Data publikacji:: 2012-05
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.10.Fd
74.20.Rp
71.27.+a
71.10.Hf
Opis:: We analyze the evolution from the weak coupling (BCS-like limit) to the strong coupling limit of tightly bound local pairs in the 2D asymmetric attractive Hubbard model, in the presence of the Zeeman magnetic field (h). The broken symmetry Hartree approximation is used. We also apply the Kosterlitz-Thouless scenario to determine the phase coherence temperatures. We obtain that for the spin dependent hopping integrals $(t^{↑} ≠ t^{↓})$ the homogeneous polarized superfluid $(SC_{M})$ phase in the ground state for the strong attraction and lower filling can be stabilized. We find a topological quantum phase transition (the Lifshitz type) from the unpolarized superfluid phase $(SC_0)$ to $SC_{M}$ and tricritical point in the (h - μ) and spin polarization (P) vs. attraction (U < 0) ground state phase diagrams. The finite temperatures phase diagrams for $t^{↑} ≠ t^{↓}$ are constructed.
Źródło:: Acta Physica Polonica A; 2012, 121, 5-6; 1066-1069
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 6.

Tytuł:: On the Imbalanced d-Wave Superfluids Within the Spin Polarized Extended Hubbard Model: Weak Coupling Limit
Autorzy:: Kujawa-Cichy, A.
Powiązania:: https://bibliotekanauki.pl/articles/1431324.pdf
Data publikacji:: 2012-04
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 71.10.Fd
74.20.Rp
71.27.+a
71.10.Hf
Opis:: We investigate the superfluid properties of d-wave pairing symmetry within the Extended Hubbard Model (EHM) in a magnetic field. We analyze the temperature and magnetic field dependencies of the order parameter. We find that in the two-dimensional case, the spatially homogeneous spin polarized superfluidity (SC(P≠0)) is stable in the weak coupling limit, at T=0, as opposed to the s-wave pairing symmetry case in 2D. We construct the ground state phase diagrams both for fixed chemical potential and electron concentration. Furthermore, we obtain the temperature vs. magnetic field and temperature vs. spin polarization phase diagrams.
Źródło:: Acta Physica Polonica A; 2012, 121, 4; 824-827
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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