Энергетический спектр и спектр оптического поглощения эндоэдральных фуллеренов Lu-=SUB=-3-=/SUB=-N@C-=SUB=-80-=/SUB=- и Y-=SUB=-3-=/SUB=-N@C-=SUB=-80-=/SUB=- в модели Хаббарда

Anticommutator Green’s functions and energy spectra of fullerene C80, endohedral fullerenes Lu3N@С80 and Y3N@С80 with the Ih symmetry groups have been obtained in an analytical form within the Hubbard model and static fluctuation approximation. The energy states have been classified using the methods of group theory, and the allowed transitions in the energy spectra of molecules C80, Lu3N@С80 and Y3N@С80have been determined. On the basis of these spectra, an interpretation of experimentally observed optical absorption bands endohedral fullerenes Lu3N@С80 and Y3N@С80.

Thermodynamic properties of spin-imbalance harmonically trapped one-dimensional attractive 6Li atomic gas

The thermodynamic properties of 6Li atomic gas system, with imbalanced spin populations trapped in one-dimension, were systematically investigated using the Static Fluctuation Approximation. The two-body interaction used is an attractive contact potential. The effects of gas parameter [Formula: see text] and spin polarization [Formula: see text], on the thermodynamic properties and effective magnetic field were investigated. We observed a decrease in [Formula: see text] and an enhancement in [Formula: see text] and [Formula: see text] with increasing [Formula: see text]. At strong interaction and at [Formula: see text], the behavior of entropy with [Formula: see text] indicated two different phases. At small spin polarization [Formula: see text], the system could be in Fulde–Ferrell–Larkin Ovchinnikov (FFLO) state, while above [Formula: see text], the system might be in normal state. In addition, we found a clear decrease in both [Formula: see text] and [Formula: see text] and an enhancement in [Formula: see text] with the increase of the interaction strength. Our results are consistent with the reported results obtained by the mean-field Bogoliubov–de Gennes method, the Bardeen–Cooper–Schrieffer (BCS) approximation and Nozieres–Schmitt–Rink (NSR) theory.

Энергетический спектр и спектр оптического поглощения фуллерена C-=SUB=-26-=/SUB=- в модели Хаббарда

Anticommutator Green’s functions and energy spectra of fullerene C26 and endohedral fullerene U@C26 with the D3h symmetry groups have been obtained in an analytical form within the Hubbard model and static fluctuation ap-proximation. The energy states have been classified using the methods of group theory, and the allowed transitions in the energy spectra of molecules C26 and U@C26 with the D3h symmetry groups have been determined.

Энергетический спектр и спектр оптического поглощения фуллерена С-=SUB=-28-=/SUB=- в модели Хаббарда

Anticommutator Green’s functions and energy spectra of fullerene C28 and endofullerene Zr@C28 with the Td symmetry groups have been obtained in an analytical form within the Hubbard model and static fluctuation approxima-tion. The energy states have been classified using the methods of group theory, and the allowed transitions in the energy spectra of fullerene C28 and endofull-erene Zr@C28 with the Td symmetry groups have been determined.

Энергетический спектр и спектр оптического поглощения фуллерена C-=SUB=-24-=/SUB=- в модели Хаббарда

Anticommutator Green’s functions and energy spectra of fullerene C24 with the D6, D6d, and Oh symmetry groups have been obtained in an analytical form within the Hubbard model and static fluctuation approximation. The energy states have been classified using the methods of group theory, and the allowed transitions in the energy spectra of fullerene C24 with the D6, D6d, and Oh symmetry groups have been determined.

Влияние деформации на энергетический спектр и спектр оптического поглощения фуллерена C-=SUB=-20-=/SUB=- в модели Хаббарда

—Anticommutator Green’s functions and energy spectra of fullerene C_20 with the I _ h , D _5 d , and D _3 d symmetry groups have been obtained in an analytical form within the Hubbard model and static fluctuation approximation. The energy states have been classified using the methods of group theory, and the allowed transitions in the energy spectra of fullerene C_20 with the I _ h , D _5 d , and D _3 d symmetry groups have been determined. It is also shown how the energy levels of fullerene C_20 with the I _ h symmetry group are split with the symmetry reduction.

A microscopic study of neon and argon gases within the static fluctuation approximation (SFA)

The thermodynamic properties of neon and argon gases are studied within the static fluctuation approximation (SFA). These properties include the total internal energy, pressure, entropy, compressibility and specific heat. The results are compared with those recently obtained within the Galitskii–Migdal–Feynman (GMF) formalism. The overall agreement is very good. An exception, however, is the specific-heat results for neon. While SFA gives results rather similar to those of the ideal gas, the corresponding GMF results are quite different. It is argued that the discrepancy seems to have arisen from quantum effects in conformity with very recent Monte Carlo computations. Whenever possible, our SFA results are compared to experimental data.