Superconducting Condensation Energy of the Two-Chain Hubbard Model in the Bulk Limit
Superconducting Condensation Energy of the Two-Chain Hubbard Model in the Bulk Limit
复制标题
体积极限下双链哈伯德模型的超导凝聚能
DOI：
10.1143/jpsj.69.2199
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发表时间：
2000
影响因子：
1.7
通讯作者：
T. Yanagisawa
中科院分区：
文献类型：
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作者：
S. Koike;K. Yamaji;T. Yanagisawa
我们利用变分蒙特卡罗方法改变链间转移能量t d ，研究了双链哈伯德模型中超导的可能性。相对于正常状态能量（只不过是超导凝聚能量），计算了变分 BCS 状态下每个位点的能量增益 Δ E。我们通过幂律函数将 Δ E 拟合为晶格尺寸倒数的函数，并发现在体积极限下 Δ E 在 t d 的某个狭窄范围内保持有限。计算的动量分布函数表明，当k空间中的电子分布处于单能带状态且处于向双能带过渡的边缘时，超导性最稳定。还检查了 SDW 型试验波函数，但我们没有在上述超导区域中获得任何能量增益。
We have studied on the possibility of superconductivity in the two-chain Hubbard model by using the variational Monte Carlo method changing the interchain transfer energy t d . The energy gain per site Δ E in the variational BCS state in reference to the normal state energy, which is nothing but the superconducting condensation energy, was computed. We have fitted Δ E as a function of the inverse of the lattice size by a power-law function and found that in the bulk limit Δ E remains finite in a certain narrow range of t d . Calculated momentum distribution functions reveal that the superconductivity is most stable in the case where the electron distribution in k -space is in a one-band-like situation, on the brink of transition to a two-band-like one. The SDW-type trial wave function was also examined but we did not obtain any energy gain with it in the above-mentioned superconducting region.
DOI：
10.1007/bf01303701
发表时间：
1986-01-01
期刊：
ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER
影响因子：
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作者：
BEDNORZ, JG;MULLER, KA
通讯作者：
MULLER, KA
影响因子：
1.7
作者：
H. Yokoyama;H. Shiba
通讯作者：
H. Yokoyama;H. Shiba
N.Kawakami：“一维量子液体的共形场论方法”Prog.Theor.Phys.Suppl.(1992)
DOI：
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