کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6919944 | 863591 | 2015 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Organization of the Hilbert space for exact diagonalization of Hubbard model
ترجمه فارسی عنوان
سازمان فضای هیلبرت برای قطب نما دقیق مدل هابارد
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کلمات کلیدی
مدل هابارد، تعریف دقیق
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
چکیده انگلیسی
We present an alternative scheme to the widely used method of representing the basis of one-band Hubbard model through the relation I=Iâ+2MIâ given by Lin and Gubernatis (1993), where Iâ, Iâ and I are the integer equivalents of binary representations of occupation patterns of spin up, spin down and both spin up and spin down electrons respectively, with M being the number of sites. We compute and store only Iâ or Iâ at a time to generate the full Hamiltonian matrix. The non-diagonal part of the Hamiltonian matrix given as IââHââHââIâ is generated using a bottom-up approach by computing the small matrices Hâ (spin up hopping Hamiltonian) and Hâ (spin down hopping Hamiltonian) and then forming the tensor product with respective identity matrices Iâ and Iâ, thereby saving significant computation time and memory. We find that the total CPU time to generate the non-diagonal part of the Hamiltonian matrix using the new one spin configuration basis scheme is reduced by about an order of magnitude as compared to the two spin configuration basis scheme. The present scheme is shown to be inherently parallelizable. Its application to translationally invariant systems, computation of Green's functions and in impurity solver part of DMFT procedure is discussed and its extension to other models is also pointed out.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Computer Physics Communications - Volume 193, August 2015, Pages 19-29
Journal: Computer Physics Communications - Volume 193, August 2015, Pages 19-29
نویسندگان
Medha Sharma, M.A.H. Ahsan,