arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 0809.2906cond-mat.mes-hall
收藏

单分子量子点中的量子相变

Quantum phase transition in a single-molecule quantum dot

Nicolas Roch, Serge Florens, Vincent Bouchiat, Wolfgang Wernsdorfer, Franck Balestro

摘要:

量子临界性是由量子力学定律提供的一种有趣的可能性,当一个多粒子物理系统的波函数被迫在两个不同的、相互竞争的基态之间不断演化时。这种现象通常与零温磁相变有关,可以在几种强相关的材料中观察到,如重费米子化合物或可能的高温超导体,并且被认为支配着它们许多迷人的,但仍然无法解释的性质。与这些具有非常复杂的电子结构的块状材料相比,人工纳米器件可以为理解量子相变提供一个新的和更简单的前景。我们在富勒烯分子结中的工作证明了这种长期寻求的可能性,其中门电压在零磁场下诱导单重态和三重态自旋态的交叉。从金属接触到$\rm{C_{60}}$量子点的电子隧穿在这里提供了必要的多体相关性,以观察真正的量子临界行为。

英文摘要:

Quantum criticality is the intriguing possibility offered by the laws of quantum mechanics when the wave function of a many-particle physical system is forced to evolve continuously between two distinct, competing ground states. This phenomenon, often related to a zero-temperature magnetic phase transition, can be observed in several strongly correlated materials such as heavy fermion compounds or possibly high-temperature superconductors, and is believed to govern many of their fascinating, yet still unexplained properties. In contrast to these bulk materials with very complex electronic structure, artificial nanoscale devices could offer a new and simpler vista to the comprehension of quantum phase transitions. This long-sought possibility is demonstrated by our work in a fullerene molecular junction, where gate voltage induces a crossing of singlet and triplet spin states at zero magnetic field. Electronic tunneling from metallic contacts into the $\rm{C_{60}}$ quantum dot provides here the necessary many-body correlations to observe a true quantum critical behavior.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑