Scholarlink

<p>The recent discovery of high-<i>T</i><sub><i>c</i></sub> superconductivity in Ruddlesden-Popper (RP) nickelates has motivated extensive efforts to explore higher-<i>T</i><sub><i>c</i></sub> superconductors. Here, we systematically investigate Nd-doped La<sub>3</sub>Ni<sub>2</sub>O<sub>7</sub> using density functional theory (DFT) and renormalized mean-field theory (RMFT). DFT calculations reveal that both the lattice constants and interlayer spacing decrease upon Nd substitution, similar to the effect of physical pressure. However, the in-plane Ni-O-Ni bond angle evolves non-monotonically with doping, increasing to a maximum at 70% (∼2/3) Nd doping level and then falling sharply at 80%, which leads to a reduction in orbital overlap. Moreover, Nd doping has a more pronounced effect on the Ni-<InlineEquation ID="IEq1"> <EquationSource Format="TEX">\(d_{z^{2}}\)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <msub> <mi>d</mi> <mrow> <msup> <mi>z</mi> <mrow> <mn>2</mn> </mrow> </msup> </mrow> </msub> </math></EquationSource> </InlineEquation> orbital, demonstrating an orbital-dependent effect of rare-earth substitution. Through the bilayer two-orbital <i>t-J</i> model, RMFT analysis further shows an <i>s</i><sub>±</sub>-wave pairing symmetry, with <i>T</i><sub><i>c</i></sub> rising to a maximum at about 70% Nd substitution before declining, in agreement with the transport measurements. The variation in <i>T</i><sub><i>c</i></sub> can be traced to the competition between continuously enhanced interlayer <InlineEquation ID="IEq2"> <EquationSource Format="TEX">\(d_{z^{2}}\)</EquationSource> <EquationSource Format="MATHML"><math display="block"> <msub> <mi>d</mi> <mrow> <msup> <mi>z</mi> <mrow> <mn>2</mn> </mrow> </msup> </mrow> </msub> </math></EquationSource> </InlineEquation> orbital hopping and a gradual decrease in electron density. These results highlight the delicate interplay among structural tuning, orbital hybridization, and superconductivity, providing important clues to design higher-<i>T</i><sub><i>c</i></sub> RP nickelate superconductors.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Electronic structures and superconductivity in Nd-doped La3Ni2O7

  • 期刊论文

  • 发表日期：

    2026年1月4日

查看全文
  • Cui-Qun Chen,
  • Wenyuan Qiu,
  • Zhihui Luo,
  • Meng Wang,
  • Dao-Xin Yao

摘要

The recent discovery of high-Tc superconductivity in Ruddlesden-Popper (RP) nickelates has motivated extensive efforts to explore higher-Tc superconductors. Here, we systematically investigate Nd-doped La3Ni2O7 using density functional theory (DFT) and renormalized mean-field theory (RMFT). DFT calculations reveal that both the lattice constants and interlayer spacing decrease upon Nd substitution, similar to the effect of physical pressure. However, the in-plane Ni-O-Ni bond angle evolves non-monotonically with doping, increasing to a maximum at 70% (∼2/3) Nd doping level and then falling sharply at 80%, which leads to a reduction in orbital overlap. Moreover, Nd doping has a more pronounced effect on the Ni- \(d_{z^{2}}\) d z 2 orbital, demonstrating an orbital-dependent effect of rare-earth substitution. Through the bilayer two-orbital t-J model, RMFT analysis further shows an s±-wave pairing symmetry, with Tc rising to a maximum at about 70% Nd substitution before declining, in agreement with the transport measurements. The variation in Tc can be traced to the competition between continuously enhanced interlayer \(d_{z^{2}}\) d z 2 orbital hopping and a gradual decrease in electron density. These results highlight the delicate interplay among structural tuning, orbital hybridization, and superconductivity, providing important clues to design higher-Tc RP nickelate superconductors.