TY - JOUR
T1 - Stripe formation in fermionic atoms on 2-D optical lattice
T2 - DMRG studies for n-leg repulsive hubbard ladder
AU - Machida, M.
AU - Okumura, M.
AU - Yamada, S.
AU - Ohashi, Y.
AU - Matsumoto, H.
N1 - Funding Information:
Acknowledgements Three of the authors (M.M., M.O., S.Y.) acknowledge M. Kohno, T. Hotta, and H. Onishi for illuminating discussion about the DMRG techniques, and one of the authors (M.O.) would like to thank H. Aoki, T. Oka, and Y. Yanase for illuminating discussion. One of the authors (M.M.) was partially supported by the Priority Area “Physics of new quantum phases in superclean materials” (Grant No. 18043022) from the Ministry of Education, Culture, Sports, Science and Technology of Japan, a JAEA internal project represented by M. Kato, and JSPS Core-to-Core Program-Strategic Research Networks, “Nanoscience and Engineering in Superconductivity (NES).”
PY - 2009/4
Y1 - 2009/4
N2 - In order to examine the ground state of the single-band Hubbard model from a slightly doped region to an overdoped one, we use the density renormalization group method extended directly to the ladder model and obtain hole profiles with changing the on-site repulsion and the doping ratio. The calculation results in a heavily underdoped region, in which one and two holes (up and down spins) are added, reveal that an attractive interaction works between holes which are confined inside a stripe shape pattern while strong disorders separate the two holes. When doping holes further within an underdoped range, the stripes formed by two holes merge and various stripe structures appear depending on U/t and the doping ratio. The remarkable finding in the underdoped region is a stripe formation composed of 4 holes analytically predicted by Chang and Affleck. On the other hand, in the overdoped range the stripe-like shape becomes very simple, i.e., only a small oscillating charge density profile emerges. These rich features in the underdoped range are relevant to electronic inhomogeneities experimentally observed in high-T c superconductors, while those are directly observable in atomic Fermi gases loaded on optical lattices.
AB - In order to examine the ground state of the single-band Hubbard model from a slightly doped region to an overdoped one, we use the density renormalization group method extended directly to the ladder model and obtain hole profiles with changing the on-site repulsion and the doping ratio. The calculation results in a heavily underdoped region, in which one and two holes (up and down spins) are added, reveal that an attractive interaction works between holes which are confined inside a stripe shape pattern while strong disorders separate the two holes. When doping holes further within an underdoped range, the stripes formed by two holes merge and various stripe structures appear depending on U/t and the doping ratio. The remarkable finding in the underdoped region is a stripe formation composed of 4 holes analytically predicted by Chang and Affleck. On the other hand, in the overdoped range the stripe-like shape becomes very simple, i.e., only a small oscillating charge density profile emerges. These rich features in the underdoped range are relevant to electronic inhomogeneities experimentally observed in high-T c superconductors, while those are directly observable in atomic Fermi gases loaded on optical lattices.
KW - Atomic Fermi gas
KW - Density-matrix renormalization group
KW - High-T superconductors
KW - Hubbard model
KW - Stripe
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U2 - 10.1007/s10948-008-0438-5
DO - 10.1007/s10948-008-0438-5
M3 - Article
AN - SCOPUS:67650886278
SN - 1557-1939
VL - 22
SP - 275
EP - 279
JO - Journal of Superconductivity and Novel Magnetism
JF - Journal of Superconductivity and Novel Magnetism
IS - 3
ER -