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arXiv 2208.03230cond-mat.str-el
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有机导体中带宽控制的Mott跃迁附近的相干重载流子

Coherent heavy charge carriers in an organic conductor near the bandwidth-controlled Mott transition

Sebastian Oberbauer, Shamil Erkenov, Werner Biberacher, Natalia D. Kushch, Rudolf Gross, Mark V. Kartsovnik

摘要:

在过去的几十年里,莫特金属-绝缘体转变(MIT)的物理学引起了人们的极大兴趣。然而,尽管做出了广泛的努力,一些关键的理论预测仍然缺乏实验证实。特别是,目前还不清楚是否大的相干费米面生存在紧邻带宽控制的一阶MIT。通过多体相互作用重整化的准粒子有效质量的预测行为的定量实验验证也不见了。在这里,我们通过采用有机$κ$型盐作为示例性准二维带宽控制的莫特绝缘体并通过磁量子振荡获得对其载流子性质的直接访问来解决这些问题。我们跟踪的有效回旋质量的演变,通过精确控制的外部压力的传导带宽调谐非常接近MIT。我们发现,质量重整化的带宽的微小变化的敏感性是显着强于理论预测,甚至进一步增强后进入过渡区的金属和绝缘相共存。另一方面,即使在其稳定性的边缘,金属基态也保持了大的相干费米表面,而没有显著的散射增强。

英文摘要:

The physics of the Mott metal-insulator transition (MIT) has attracted huge interest in the last decades. However, despite broad efforts, some key theoretical predictions are still lacking experimental confirmation. In particular, it is not clear whether the large coherent Fermi surface survives in immediate proximity to the bandwidth-controlled first-order MIT. A quantitative experimental verification of the predicted behavior of the quasiparticle effective mass, renormalized by many-body interactions, is also missing. Here we address these issues by employing organic $κ$-type salts as exemplary quasi-two-dimensional bandwidth-controlled Mott insulators and gaining direct access to their charge carrier properties via magnetic quantum oscillations. We trace the evolution of the effective cyclotron mass as the conduction bandwidth is tuned very close to the MIT by means of precisely controlled external pressure. We find that the sensitivity of the mass renormalization to tiny changes of the bandwidth is significantly stronger than theoretically predicted and is even further enhanced upon entering the transition region where the metallic and insulating phases coexist. On the other hand, even at its very edge of stability the metallic ground state preserves a large coherent Fermi surface with no significant enhancement of scattering.

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。

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