Discovery of Superconductivity in a Strongly Correlated Chromium-Based Kagome Metal under High Pressure

核心概念

A chromium-based kagome metal, CsCr3Sb5, exhibits strong electron correlations, frustrated magnetism, and characteristic flat bands near the Fermi level. Under high pressure, the material's density-wave-like orders are suppressed, leading to the emergence of a superconducting dome with a maximum transition temperature of 6.4 K, suggesting the potential for unconventional superconductivity in correlated kagome systems.

摘要

The article reports the discovery of a chromium-based kagome metal, CsCr3Sb5, which exhibits strong electron correlations, frustrated magnetism, and flat bands near the Fermi level. Under ambient pressure, the material undergoes a concurrent structural and magnetic phase transition at 55 K, with a stripe-like 4a0 structural modulation.

At high pressure, the phase transition evolves into two transitions, possibly associated with charge-density-wave and antiferromagnetic spin-density-wave orderings. These density-wave-like orders are gradually suppressed with increasing pressure, and remarkably, a superconducting dome emerges at 3.65-8.0 GPa. The maximum superconducting transition temperature, Tcmax = 6.4 K, is observed when the density-wave-like orders are completely suppressed at 4.2 GPa, and the normal state exhibits a non-Fermi-liquid behavior, reminiscent of unconventional superconductivity and quantum criticality in iron-based superconductors.

The authors suggest that this chromium-based kagome metal offers an unprecedented platform for investigating superconductivity in correlated kagome systems, which has been theoretically proposed but experimentally challenging to achieve.

统计

The material undergoes a concurrent structural and magnetic phase transition at 55 K under ambient pressure.
The superconducting dome emerges at 3.65-8.0 GPa, with a maximum transition temperature of Tcmax = 6.4 K at 4.2 GPa.

引用

"Superconductivity in a highly correlated kagome system has been theoretically proposed for years (refs. 1,2,3,4,5), yet the experimental realization is hard to achieve6,7."
"Our work offers an unprecedented platform for investigating superconductivity in correlated kagome systems."

从中提取的关键见解

Superconductivity under pressure in a chromium-based kagome metal - Nature

by Yi Liu,Zi-Yi... 在 www.nature.com 08-28-2024

https://www.nature.com/articles/s41586-024-07761-x

更深入的查询

What are the specific mechanisms driving the emergence of superconductivity in this strongly correlated chromium-based kagome metal under high pressure?

The emergence of superconductivity in the strongly correlated chromium-based kagome metal, CsCr3Sb5, under high pressure can be attributed to the suppression of density-wave-like orders. As pressure is increased, the density-wave-like orders gradually diminish, leading to the formation of a superconducting dome between 3.65–8.0 GPa. At around 4.2 GPa, when these density-wave-like orders are completely suppressed, the material exhibits a maximum superconducting transition temperature, Tcmax = 6.4 K. This suggests that the superconductivity in this system is closely linked to the suppression of competing electronic orders, allowing for the emergence of the superconducting state.

How do the electronic and magnetic properties of this material evolve as the density-wave-like orders are suppressed, and what insights can this provide into the nature of the superconducting state?

As the density-wave-like orders are suppressed in the chromium-based kagome metal, CsCr3Sb5, under high pressure, the electronic and magnetic properties of the material undergo significant changes. The material transitions from a state characterized by strong electron correlations, frustrated magnetism, and density-wave-like orders to a superconducting state with a non-Fermi-liquid behavior in the normal state. This evolution suggests a close connection between the suppression of competing electronic orders and the onset of superconductivity. The emergence of unconventional superconductivity and quantum criticality in the material at high pressure indicates that the superconducting state may be intertwined with the underlying electronic and magnetic properties, offering insights into the nature of superconductivity in correlated kagome systems.

Given the potential for unconventional superconductivity in correlated kagome systems, what other materials in this class could be explored, and what experimental techniques or theoretical approaches might be most fruitful for further investigations?

In light of the potential for unconventional superconductivity in correlated kagome systems demonstrated by CsCr3Sb5, other materials in this class that exhibit strong electron correlations, frustrated magnetism, and flat bands near the Fermi level could be promising candidates for exploration. Materials with similar kagome lattice structures but different transition metal elements could be investigated to understand the role of electronic correlations and magnetic interactions in driving superconductivity. Experimental techniques such as high-pressure studies, angle-resolved photoemission spectroscopy (ARPES), neutron scattering, and transport measurements could provide valuable insights into the electronic and magnetic properties of these materials. Theoretical approaches, including computational modeling based on strong correlation physics and symmetry analysis, could also help elucidate the mechanisms underlying unconventional superconductivity in correlated kagome systems.