Superconductivity in pressurized trilayer La₄Ni₃O_10-δ single crystals

Area of Science:

• Condensed Matter Physics
• Materials Science
• Solid-State Chemistry

Background:

• The search for high-temperature superconductors beyond traditional copper-based materials is crucial for advancing scientific understanding and technological applications.
• Understanding the mechanisms of superconductivity requires exploring novel material systems and their electronic properties.

Purpose of the Study:

• To investigate the emergence of superconductivity in trilayer nickelate La₄Ni₃O₁₀-δ single crystals under pressure.
• To explore the relationship between spin-charge order, strange metal behavior, and superconductivity in nickelates.
• To elucidate the unique interlayer coupling mechanisms in nickelate superconductors.

Main Methods:

• Single crystal growth of La₄Ni₃O₁₀-δ.
• Application of high pressure (up to 69.0 GPa).
• Measurement of electrical resistance and d.c. magnetic susceptibility.

Main Results:

• Superconductivity emerged in La₄Ni₃O₁₀-δ at a maximum critical temperature (T_c) of ~30 K under 69.0 GPa.
• Pressure suppressed spin-charge order, facilitating superconductivity.
• Bulk superconductivity with >80% volume fraction was confirmed by diamagnetic response.
• The normal state exhibited strange metal behavior with linear temperature-dependent resistance up to 300 K.
• Layer-dependent superconductivity indicated unique interlayer coupling in nickelates.

Conclusions:

• High pressure is an effective tool to induce and tune superconductivity in trilayer nickelates.
• La₄Ni₃O₁₀-δ presents a new platform for studying the interplay of spin-charge order, flat bands, interlayer coupling, and strange metal behavior in the context of high-temperature superconductivity.
• Nickelate superconductors exhibit distinct properties compared to cuprates, particularly regarding interlayer coupling mechanisms.