受近期关于 La$_3$Ni$_2$O$_7$ 在压力下呈现高 $T_c$ 超导性报道的启发,我们从理论上分析了该化合物在正常态和超导态中的磁激发,这些激发可通过非弹性中子散射或 RIXS 测量。我们表明,自旋响应的双层结构能够以非常高效的方式阐明层间相互作用的作用以及 Cooper 配对的本质。特别是,我们通过比较自旋极化率在偶数和奇数通道中的相应响应,证明了近期提出的潜在 $s_\pm$ 能隙与 $d$ 波能隙之间的关键差异。我们表明,主要由层间驱动的成键-反键 $s_\pm$ Cooper 配对仅在 $X$ 点附近的奇数通道中产生单个大的自旋共振峰,而在 $d$ 波情形下,则预测奇数和偶数通道中均存在自旋共振。
英文摘要:
Motivated by the recent reports of high-$T_c$ superconductivity in La$_3$Ni$_2$O$_7$ under pressure, we analyzed theoretically the magnetic excitations in the normal and the superconducting state in this compound, which can be measured by inelastic neutron scattering or RIXS. We show that the bilayer structure of the spin response allows to elucidate the role of the interlayer interaction and the nature of the Cooper-pairing in a very efficient way. In particular, we demonstrate the key difference between the potential $s_\pm$ and $d$-wave gaps, proposed recently, by comparing the corresponding response in the even and odd channels of the spin susceptibility. We show that the mostly interlayer driven bonding-antibonding $s_\pm$ Cooper-pairing produces a single large spin resonance peak in the odd channel only near the $X$ point whereas spin resonances in both the odd and the even channel are predicted for the $d$-wave scenario.
Emergent flat-band physics in $d^{9-δ}$ multilayer nickelates
最近的实验表明,形式为RE $_{p+1}$ Ni $_p$ O $_{2p+2}$的还原多层稀土(RE)镍氧化物可能属于超导镧系镍酸盐的新家族。本文采用改进的真实多体框架研究了Pr $_{4}$ Ni $_3$ O $_{8}$和Nd $_{6}$ Ni $_5$ O $_{12}$的相关电子结构。结果表明,Ni- $d_{x^2-y^2}$和Ni- $d_{z^2}$自由度的相互作用决定了这两个体系的低能物理性质.虽然Ni- $d_{x^2-y^2}$轨道总是在(轨道选择性)Mott绝缘区域附近高度相关,但Ni- $d_{z^2}$轨道产生有趣的非色散特征。在低温下,Pr化合物在费米能级上仍表现出类似量子点的Ni- $d_{x^2-y^2}$衍生态,但Nd化合物的相互作用费米能级被Ni- $d_{z^2}$控制的平带所掩盖.这些发现很好地转化为以前的表征掺杂的无限层镍酸盐,因此进一步使一种非常规的超导机制的情况下,这是从一个不同的高- $T_{\rm c}$铜酸盐。
Magnetic configurations and excitations in high-$T_{c}$ multilayer nickelates
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所,凝聚态物理北京国家实验室);School of Physical Sciences, University of Chinese Academy of Sciences(中国科学院大学物理科学学院);Institute of Theoretical Physics, Chinese Academy of Sciences(中国科学院理论物理研究所);New Cornerstone Science Laboratory, Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所,新基石科学实验室)
Itinerant Nature of Spin-Density-Wave Order in Ruddlesden-Popper Nickelates
Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所);School of Physical Sciences, University of Chinese Academy of Sciences(中国科学院大学物理科学学院)
Heterostructuring as Gateway to Electron Doping of Nickelate Superconductors
Northwest University(西北大学);University of Hyogo(兵库大学);Kyushu Institute of Technology(九州工业大学);Soochow University(苏州大学);Universität Würzburg(维尔茨堡大学);Southeast University(东南大学);University of Science and Technology of China(中国科学技术大学);TU Wien(维也纳工业大学)
Electronic structures across superconductor-insulator transition in Ruddlesden-Popper bilayer nickelate films
University of Science and Technology of China(中国科学技术大学);Hefei National Laboratory, University of Science and Technology of China(合肥国家实验室,中国科学技术大学);Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China(微观尺度物理科学合肥国家研究中心,中国科学技术大学);Southern University of Science and Technology(南方科技大学);Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(粤港澳大湾区量子科学中心);Nanjing University(南京大学);Shanghai Jiao Tong University(上海交通大学);Tsinghua University(清华大学)
Superconductor-insulator transitions in infinite-layer nickelates controlled via ${operando}$ monitored reduction
Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(粤港澳大湾区量子科学中心);State Key Laboratory of Quantum Functional Materials, Department of Physics, and Guangdong Basic Research Center of Excellence for Quantum Science, Southern University of Science and Technology(南方科技大学);National Laboratory of Solid-State Microstructures, College of Engineering and Applied Sciences, Nanjing University(南京大学);Department of Physics, City University of Hong Kong(香港城市大学);Shenzhen Research Institute of City University of Hong Kong(香港城市大学(深圳)研究院);Department of Physics, Tsinghua University(清华大学)
Bosonic phases across the superconductor-insulator transition in infinite-layer samarium nickelate
Beijing Academy of Quantum Information Sciences(北京量子信息科学研究院);Quantum Science Center of Guangdong-Hong Kong-Macao Greater Bay Area(粤港澳大湾区量子科学中心);Southern University of Science and Technology(南方科技大学);City University of Hong Kong(香港城市大学);Shenzhen Research Institute of City University of Hong Kong(香港城市大学深圳研究院);Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所);University of Chinese Academy of Sciences(中国科学院大学);Hefei National Laboratory(合肥国家实验室);Peking University(北京大学);Tsinghua University(清华大学)
Emergent quantum phenomena via phase-coherence engineering in infinite-layer nickelate superconductors
Peking University(北京大学);University of Electronic Science and Technology of China(电子科技大学);Renmin University of China(中国人民大学);ShanghaiTech University(上海科技大学);Tsinghua University(清华大学);Institute of Physics Chinese Academy of Sciences(中国科学院物理研究所);University of Chinese Academy of Sciences(中国科学院大学);Songshan Lake Materials Laboratory(松山湖材料实验室);Beijing Normal University(北京师范大学);Fudan University(复旦大学);Hefei National Laboratory(合肥国家实验室)
Electronic structure and correlations in planar trilayer nickelate Pr4Ni3O8
最近发现的空穴掺杂平面镍酸盐R1-xSrNiO 2(R=Pr,Nd)的超导电性提出了一个基本的问题,这些Ni 1+化合物的电子结构和电子相关性如何比较的Cu 2+铜酸盐超导体。在这里,我们提出了一个角度分辨光电子能谱(ARPES)研究的三层镍酸盐Pr 4 Ni 3 O 8,揭示了电子结构和费米表面非常相似的空穴掺杂的铜酸盐,但有一些关键的差异。具体地说,费米表面的主要部分与双层铜氧化物的费米表面非常相似,但有一个额外的部分可以容纳额外的空穴掺杂。我们发现,电子的相关性是镍酸盐的两倍强,几乎是k-独立的,这表明它们起源于一个本地的效果可能的莫特相互作用,而铜酸盐的相互作用是有点不那么本地。尽管如此,镍酸盐仍然表现出近似线性的能量和线性的温度散射率。理解这两个相关的强关联新型超导体家族之间的相似性和差异是一个重要的挑战。
Multiorbital character of the density wave in trilayer nickelate superconductors
Max-Planck-Institute for Solid State Research(马克斯·普朗克固体研究所);Facultad de Ciencias Exactas, Ingeniería y Agrimensura and Instituto de Física Rosario (UNR-CONICET)(罗萨里奥大学精确科学、工程与测量学院及罗萨里奥物理研究所(UNR-CONICET));RIKEN Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS)(理化学研究所跨学科理论与数学科学中心 (iTHEMS))
Controlling the Band Filling and the Band Width in Nickelate Superconductors
RIKEN Center for Emergent Matter Science (CEMS)(理化学研究所 emergent matter science 中心);RIKEN Pioneering Research Institute(理化学研究所 先锋研究院);The University of Tokyo(东京大学);Department of Applied Physics, The University of Tokyo(东京大学 应用物理系);Institute of Engineering Innovation, The University of Tokyo(东京大学 工程创新研究所);Nanostructures Research Laboratory, Japan Fine Ceramics Center(日本精细陶瓷中心 纳米结构研究实验室)
$d$-wave superconductivity in quintuple-layer bulk superconductor La$_6$Ni$_5$O$_{12}$
Beijing National Laboratory for Condensed Matter Physics(北京凝聚态物理国家研究中心);Institute of Physics, Chinese Academy of Sciences(中国科学院物理研究所);Kavli Institute for Theoretical Sciences, University of Chinese Academy of Sciences(中国科学院大学卡尔丹理论科学研究所);School of Physical Science and Technology, ShanghaiTech University(上海科技大学理学院);School of Physical Sciences, University of Chinese Academy of Sciences(中国科学院大学物理科学学院);New Cornerstone Science Laboratory(新Cornerstone科学实验室)