Cooper instability in the occupation dependent hopping Hamiltonians
A generic Hamiltonian, which incorporates the effect of the orbital contraction on the hopping amplitude between nearest sites, is studied both analytically at the weak coupling limit and numerically at the intermediate and strong coupling regimes for a finite atomic cluster. The effect of the orbit...
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| Опубліковано в: : | Физика низких температур |
|---|---|
| Дата: | 1999 |
| Автори: | , |
| Формат: | Стаття |
| Мова: | English |
| Опубліковано: |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України
1999
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| Онлайн доступ: | https://nasplib.isofts.kiev.ua/handle/123456789/138988 |
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| Назва журналу: | Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| Цитувати: | Cooper instability in the occupation dependent hopping Hamiltonians / H. Boyaci, I.O. Kulik // Физика низких температур. — 1999. — Т. 25, № 8. — С. 838-849. — Бібліогр.: 31 назв. — англ. |
Репозитарії
Digital Library of Periodicals of National Academy of Sciences of Ukraine| id |
nasplib_isofts_kiev_ua-123456789-138988 |
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dspace |
| spelling |
Boyaci, H. Kulik, I.O. 2018-06-19T18:21:31Z 2018-06-19T18:21:31Z 1999 Cooper instability in the occupation dependent hopping Hamiltonians / H. Boyaci, I.O. Kulik // Физика низких температур. — 1999. — Т. 25, № 8. — С. 838-849. — Бібліогр.: 31 назв. — англ. 0132-6414 https://nasplib.isofts.kiev.ua/handle/123456789/138988 A generic Hamiltonian, which incorporates the effect of the orbital contraction on the hopping amplitude between nearest sites, is studied both analytically at the weak coupling limit and numerically at the intermediate and strong coupling regimes for a finite atomic cluster. The effect of the orbital contraction due to hole localization at atomic sites is specified with two coupling parameters V and W (multiplicative and additive contraction terms). The singularity of the vertex part of the two-particle Green`s function determines the critical temperature Tc and the relaxation rate Г(T) of the order parameter at temperature above Tc. Unlike the case in conventional BCS superconductors, Г has a non-zero imaginary part which may influence the fluctuation conductivity of the superconductor above Tc. We compute the ground state energy as a function of the particle number and magnetic flux through the cluster, and show the existence of the parity gap D appearing at the range of system parameters consistent with the appearance of the Cooper instability. Numeric calculation of the Hubbard model (with U > 0) at arbitrary occupation does not show any sign of superconductivity in a small cluster. This work was partially supported by the Scientific and Technical Research Council of Turkey (TUBITAK) through the BDP program. en Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України Физика низких температур Свеpхпpоводимость, в том числе высокотемпеpатуpная Cooper instability in the occupation dependent hopping Hamiltonians Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Cooper instability in the occupation dependent hopping Hamiltonians |
| spellingShingle |
Cooper instability in the occupation dependent hopping Hamiltonians Boyaci, H. Kulik, I.O. Свеpхпpоводимость, в том числе высокотемпеpатуpная |
| title_short |
Cooper instability in the occupation dependent hopping Hamiltonians |
| title_full |
Cooper instability in the occupation dependent hopping Hamiltonians |
| title_fullStr |
Cooper instability in the occupation dependent hopping Hamiltonians |
| title_full_unstemmed |
Cooper instability in the occupation dependent hopping Hamiltonians |
| title_sort |
cooper instability in the occupation dependent hopping hamiltonians |
| author |
Boyaci, H. Kulik, I.O. |
| author_facet |
Boyaci, H. Kulik, I.O. |
| topic |
Свеpхпpоводимость, в том числе высокотемпеpатуpная |
| topic_facet |
Свеpхпpоводимость, в том числе высокотемпеpатуpная |
| publishDate |
1999 |
| language |
English |
| container_title |
Физика низких температур |
| publisher |
Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України |
| format |
Article |
| description |
A generic Hamiltonian, which incorporates the effect of the orbital contraction on the hopping amplitude between nearest sites, is studied both analytically at the weak coupling limit and numerically at the intermediate and strong coupling regimes for a finite atomic cluster. The effect of the orbital contraction due to hole localization at atomic sites is specified with two coupling parameters V and W (multiplicative and additive contraction terms). The singularity of the vertex part of the two-particle Green`s function determines the critical temperature Tc and the relaxation rate Г(T) of the order parameter at temperature above Tc. Unlike the case in conventional BCS superconductors, Г has a non-zero imaginary part which may influence the fluctuation conductivity of the superconductor above Tc. We compute the ground state energy as a function of the particle number and magnetic flux through the cluster, and show the existence of the parity gap D appearing at the range of system parameters consistent with the appearance of the Cooper instability. Numeric calculation of the Hubbard model (with U > 0) at arbitrary occupation does not show any sign of superconductivity in a small cluster.
|
| issn |
0132-6414 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/138988 |
| citation_txt |
Cooper instability in the occupation dependent hopping Hamiltonians / H. Boyaci, I.O. Kulik // Физика низких температур. — 1999. — Т. 25, № 8. — С. 838-849. — Бібліогр.: 31 назв. — англ. |
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2025-12-07T16:23:56Z |
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2025-12-07T16:23:56Z |
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1850867330569994240 |