Autor: Koper, A. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Simple Band Model of Doped Fullerene Crystal
Autorzy:: Koper, A.
Mucha, M.
Powiązania:: https://bibliotekanauki.pl/articles/2012907.pdf
Data publikacji:: 2000-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.20.Mn
74.25.Kc
74.25.Jb
Opis:: We use quantum billiard with many scattering centers to describe conducting electrons properties in A$\text{}_{n}$C$\text{}_{60}$ crystals, where A denotes alkali metal. We focus our attention on the A$\text{}_{3}$C$\text{}_{60}$ crystal, for which we calculate the band structure, density of states, and conductivity for normal electrons. Conductivity shows linear dependence on temperature in this model, which agrees well with experimental data. We also discuss consequences of our results for superconductivity mechanism in A$\text{}_{3}$C$\text{}_{60}$ and possibilities of analogous approach to describe electron properties in fused fullerenes and multiply connected carbon clusters.
Źródło:: Acta Physica Polonica A; 2000, 97, 1; 233-236
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Relation of Gutzwiller Variational State with Matrix Model
Autorzy:: Koper, A.
Mucha, M.
Powiązania:: https://bibliotekanauki.pl/articles/1955829.pdf
Data publikacji:: 1997-02
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 02.70.Lq
02.50.Ng
11.10.-z
71.27.+a
71.10.-w
Opis:: It is shown that mean values of electron operators in variational Gutzwiller state are equal to mean values of corresponding classical quantities calculated by means of a hermitian matrix model. In cases with small number of electrons in the system this property enables exact calculation of the mean values. In case of large number of electrons a simple and effective Monte Carlo method is formulated (within matrix model).
Źródło:: Acta Physica Polonica A; 1997, 91, 2; 391-394
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: On Electrons in Quantum Chaos State in Doped Fullerene Crystal
Autorzy:: Koper, A.
Mucha, M.
Powiązania:: https://bibliotekanauki.pl/articles/2012904.pdf
Data publikacji:: 2000-01
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.45.+b
61.48.+c
Opis:: We show that band electrons in A$\text{}_{n}$C$\text{}_{60}$ crystal (C$\text{}_{60}$ fullerene doped with alkali ions A) are in highly chaotic quantum state. We describe intensity of the chaos by means of the Shannon information entropy, which we calculate using single particle Bloch functions. The entropy provides a quantitative measure of scars as well as degree of electrons delocalization in gaps between C$\text{}_{60}$ molecules. Implications of our results for conductivity in A$\text{}_{3}$C$\text{}_{60}$ are discussed.
Źródło:: Acta Physica Polonica A; 2000, 97, 1; 229-232
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: On Stability of Frustrated Quantum Magnetic States in Fullerenes
Autorzy:: Koper, A.
Mucha, M.
Powiązania:: https://bibliotekanauki.pl/articles/1964713.pdf
Data publikacji:: 1997-08
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 74.70.Wz
61.46.+w
71.10.-w
71.27.+a
75.10.Jm
02.50.Ng
02.70.Lq
Opis:: Gutzwiller variational ground states |Φ$\text{}^{G}$⟩ of π electrons, described by single-band half-filling Hubbard model, were determined for the molecules C$\text{}_{60}$ and C$\text{}_{70}$ and their energies and magnetic properties investigated. To construct these states two types of trial functions were used: generalized spin-density wave |Φ$\text{}_{SD}$⟩ and tight-binding wave |Φ$\text{}_{ΤΒ}$⟩. Our results evidently show that the Gutzwiller state |Φ$\text{}_{TΒ}^{G}$⟩ determined by means of function |Φ$\text{}_{ΤΒ}$⟩ has lower energy than the other investigated variational states |Φ$\text{}_{SD}^{G}$⟩. Mean values of the operators in the Gutzwiller states were calculated using Monte Carlo method.
Źródło:: Acta Physica Polonica A; 1997, 92, 2; 395-398
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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