| 查看: 38 | 回复: 0 | |||
yexuqing木虫之王 (文学泰斗)
太阳系系主任
|
[交流]
分子自旋链与超导体的宇称依赖耦合
|
|
Parity-dependent coupling of molecular spin chains to a superconductor 分子自旋链与超导体的宇称依赖耦合 ▲ 作者：Katerina Vaxevani, Jon Ortuzar, Stefano Trivini, Georg Monninger, Dongfei Wang, Manuel Vilas-Varela, Lucía Gómez-Rodrigo, Diego Pena & Jose Ignacio Pascual ▲链接： https://www.nature.com/articles/s41586-026-11117-y ▲摘要： 量子材料中的集体行为可以产生仅携带其组成单元部分量子数的激发。一个显著的例子出现在自旋为1的单元链中，其中拓扑能隙保护链的内部，而自旋为1/2的态——即构成链的单元自旋的一半——出现在末端。在短链中，这些分数化边缘自旋相互耦合，其拓扑保护使其对于混合自旋—超导器件具有吸引力。然而，这种分数化能否在超导凝聚体附近存活，仍是一个未决问题。 研究者在近邻化的Au（111）/Nb（110）衬底上生长了由反铁磁耦合的自旋为1三角烯单元构成的分子霍尔丹链，并通过扫描隧道光谱解析了其自旋为1/2边缘态与超导体的宇称依赖耦合。奇数长度链在超导能隙内承载尤—希巴—鲁西诺夫（YSR）束缚态，起源于全局S = 1基态；而偶数长度链形成S=0基态，与超导体解耦。 双格点模型将这种交替归因于边缘间相互作用的符号和强度，并由隧道谱中的额外能隙自旋激发独立证实。S=1链的多体自旋激发也被检测到，其因大得多的霍尔丹能隙而与超导体解耦。边缘自旋与超导体的长度可调耦合为基于π共轭碳架构的分子自旋量子比特开辟了一条途径。 ▲ Abstract： Collective behaviour in quantum materials can produce excitations carrying only a fraction of the quantum numbers of their constituents. A notable case occurs in chains of spin-1 units, in which a topological gap protects the interior of the chain, whereas spin-1/2 states, half the spin of the units that form it, emerge at the ends. In short chains, these fractional edge spins couple to each other and their topological protection makes them attractive for hybrid spin–superconductor devices. Whether such fractionalization survives the proximity of a superconducting condensate, however, remains an open question. Here we grow molecular Haldane chains of antiferromagnetically coupled spin-1 triangulene units on a proximitized Au(111)/Nb(110) surface and resolve a parity-dependent coupling of their spin-1/2 edge states to the superconductor by scanning tunnelling spectroscopy. Odd-length chains host Yu–Shiba–Rusinov (YSR) bound states inside the superconducting gap, originating from a global S = 1 ground state, whereas even-length chains form an S = 0 ground state decoupled from the superconductor. A two-site model attributes this alternation to the sign and strength of inter-edge interactions, independently confirmed by extra-gap spin excitations in tunnelling spectra. Many-body spin excitations of the S = 1 chain are also detected, decoupled from the superconductor by the much larger Haldane gap. The length-tunable coupling of the edge spins to superconductors opens a route towards molecular spin qubits based on π-conjugated carbon architectures. |
回复此楼» 猜你喜欢
郑州大学申博
已经有4人回复
-
40+中年人失业后，还能找到好工作吗？
已经有18人回复
-
人工智能虚构史料、伪造文献频现，多家期刊声明抵制
已经有5人回复
-
CsPbI2Br全无机钙钛矿SEM图像异常分析
已经有8人回复
-
申请科研项目纯靠实力能成功吗？
已经有12人回复
» 本主题相关商家推荐: (我也要在这里推广)
