کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5492412 | 1525682 | 2017 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
The role of local repulsion in superconductivity in the Hubbard-Holstein model
ترجمه فارسی عنوان
نقش انفجار موضعی در ابررسانایی در مدل هابارد-هولشتاین
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کلمات کلیدی
ابررسانایی، اصطلاح هابارد، پلارون،
موضوعات مرتبط
مهندسی و علوم پایه
فیزیک و نجوم
فیزیک ماده چگال
چکیده انگلیسی
We examine the superconducting solution in the Hubbard-Holstein model using Dynamical Mean Field Theory. The Holstein term introduces the site-independent Boson fields coupling to local electron density, and has two competing influences on superconductivity: The Boson field mediates the effective electron-electron attraction, which is essential for the S-wave electron pairing; the same coupling to the Boson fields also induces the polaron effect, which makes the system less metallic and thus suppresses superconductivity. The Hubbard term introduces an energy penalty U when two electrons occupy the same site, which is expected to suppress superconductivity. By solving the Hubbard-Holstein model using Dynamical Mean Field theory, we find that the Hubbard U can be beneficial to superconductivity under some circumstances. In particular, we demonstrate that when the Boson energy Ω is small, a weak local repulsion actually stabilizes
the S-wave superconducting state. This behavior can be understood as an interplay between superconductivity, the polaron effect, and the on-site repulsion: As the polaron effect is strong and suppresses superconductivity in the small Ω regime, the weak on-site repulsion reduces the polaron effect and effectively enhances superconductivity. Our calculation elucidates the role of local repulsion in the conventional S-wave superconductors.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Physica C: Superconductivity and its Applications - Volume 532, 15 January 2017, Pages 27-32
Journal: Physica C: Superconductivity and its Applications - Volume 532, 15 January 2017, Pages 27-32
نویسندگان
Chungwei Lin, Bingnan Wang, Koon Hoo Teo,