Superconducting diode effect and interference patterns in kagome CsV₃Sb₅.

Area of Science:

• Condensed Matter Physics
• Quantum Materials
• Topological Matter

Background:

• Kagome systems, like AV3Sb5 (A = K, Rb, Cs), host complex quantum states due to frustrated lattice geometry, band topology, and electron correlations.
• AV3Sb5 compounds exhibit multiple symmetry-breaking transitions, including charge ordering, nematicity, and superconductivity, with the superconducting order's nature remaining unclear.

Purpose of the Study:

• To investigate the nature of superconductivity in intrinsic cesium vanadium antimonide (CsV3Sb5) flakes.
• To explore the potential for dynamic superconducting order and time-reversal symmetry breaking in this topological kagome system.

Main Methods:

• Experimental observation of magnetic field-free superconducting diode effect.
• Analysis of critical current behavior under external magnetic fields, including interference patterns.
• Investigation of thermal history and cycling effects on superconducting properties.

Main Results:

• Indication of dynamic superconducting domains with boundary supercurrents in CsV3Sb5.
• Observation of a magnetic field-free superconducting diode effect with polarity dependent on thermal history.
• Superconductivity interference patterns consistent with periodically modulated supercurrents along domain boundaries.

Conclusions:

• The findings imply a time-reversal symmetry-breaking superconducting order in CsV3Sb5.
• The observed phenomena suggest dynamic superconducting domains and boundary supercurrents.
• This system offers a platform for exploring exotic physics, such as Majorana zero modes, in topological kagome materials.