Charge-density-wave-driven electronic nematicity in a kagome superconductor.

Area of Science:

• Condensed Matter Physics
• Quantum Materials

Background:

• Electronic nematicity is a phenomenon where electronic degrees of freedom break rotational symmetry.
• It is observed in quantum fluids like high-temperature superconductors and quantum Hall systems.
• The interplay between electronic nematicity, superconductivity, and charge-density-wave (CDW) order in AV3Sb5 materials is not well understood.

Purpose of the Study:

• To investigate the presence and nature of electronic nematicity in CsV3Sb5.
• To understand the relationship between CDW order and potential nematicity in this material.
• To explore the implications of electronic nematicity for superconductivity mechanisms.

Main Methods:

• Elastoresistance measurements to detect changes in resistance due to strain.
• Nuclear Magnetic Resonance (NMR) spectroscopy to probe local magnetic and electronic environments.
• Scanning Tunnelling Microscopy/Spectroscopy (STM/S) for atomic-scale visualization of electronic structure and order.

Main Results:

• Evidence for electronic nematicity in CsV3Sb5 was found, distinct from a previously observed C2 structural distortion.
• Nematic fluctuations emerge below the CDW transition temperature (~94 K), with a distinct nematic transition occurring around 35 K.
• STM/S directly visualized long-range nematic order, suggesting a novel nematicity potentially described by a three-state Potts model.

Conclusions:

• CsV3Sb5 exhibits intrinsic electronic nematicity in its normal state.
• This finding establishes a new paradigm for understanding the role of electronic nematicity in unconventional superconductors.
• The interplay between CDW order, nematicity, and superconductivity in CsV3Sb5 warrants further investigation.