摘要
本文采用密度矩阵重正化群方法，研究了强链间耦合的三腿t-J梯子近1/3填充时的基态性质。在空穴掺杂进入1/3填充的自旋能隙态时，对关联函数呈幂律衰减，而自旋关联函数呈指数衰减；相反，电子掺杂并未显著增强对关联。进一步对比了三腿Hubbard模型，发现空穴掺杂态的对关联特性与t-J模型类似，但需足够大的自旋能隙。研究表明，空穴掺杂近1/3填充态有利于超导配对，这一非对称配对性质与弱耦合理论预测的相图不同，为理解三层镍酸盐超导体的电子特性提供了数值依据。
材料
- three-leg t-J ladder model
- three-leg Hubbard model
方法
关键词
- pairing correlation
- spin gap
- hole doping
- 1/3 filling
- luther emery liquid
亮点
- Asymmetric pairing nature across the 1/3 filling line in the t-J model differs from weak-coupling theory predictions.
- Provides numerical evidence for understanding electronic properties of trilayer nickelate superconductors.
结论
- Hole doping into the spin-gapped state at 1/3 filling leads to power-law decay of pair correlations and exponential decay of spin correlations, indicating a pairing favorable state.
- Electron doping does not significantly enhance pair correlations.
- The pairing properties of the hole-doped state in the Hubbard model require a sufficiently large spin gap.
主要论断
- When holes are doped into the spin-gapped state at 1/3 filling, pair correlations exhibit power-law decay while spin correlations decay exponentially.
- 证据: When holes are doped into the spin-gapped state at 1/3 filling, the pairing correlation function exhibits power-law decay while the spin correlation function decays exponentially
- Electron doping does not give rise to substantial pair correlations.
- 证据: in contrast, electron doping does not significantly enhance pairing correlations
- The hole-doped state near 1/3 filling is suitable for the emergence of superconductivity, and this asymmetric pairing nature differs from weak-coupling predictions.
- 证据: The study indicates that hole doping near 1/3 filling favors superconducting pairing, and this asymmetric pairing property differs from the phase diagram predicted by weak-coupling theory
研究流程
- model definition — At1/3 filling with strong interchain couplings, the system has a spin gap and short-range spin correlations.
- 材料: three-leg t-J ladder
- 方法: density matrix renormalization group (DMRG)
- 观察: spin-gapped state at 1/3 filling
- hole doping analysis — Hole doping near 1/3 filling induces superconducting pairing with power-law decay.
- 材料: three-leg t-J ladder with holes
- 方法: DMRG calculation of pair and spin correlation functions
- 观察: pair correlations show power-law decay; spin correlations decay exponentially
- electron doping analysis — Electron doping does not significantly enhance pairing correlations.
- 材料: three-leg t-J ladder with electrons
- 方法: DMRG
- 观察: pair correlations do not develop substantially; spin correlations become more long-ranged
- comparison with Hubbard model — The pairing properties in the Hubbard model require a sufficiently large spin gap to develop, similar to the t-J model.
- 材料: three-leg Hubbard ladder
- 方法: DMRG
- 观察: pair correlations in Hubbard model are comparable to t-J model only when spin gap is sufficiently large