[Paper Review] Superconductivity in pressurized trilayer La$_4$Ni$_3$O$_{10-δ}$ single crystals

Yinghao Zhu, Di Peng+28 more|arXiv (Cornell University)|Nov 13, 2023

Rare-earth and actinide compounds48 references8 citations

TL;DR

The study shows that applying high pressure to trilayer La4Ni3O10-δ induces bulk superconductivity with Tc ≈ 30 K at 69.0 GPa, accompanied by strange metal behavior and layer-dependent coupling.

ABSTRACT

The pursuit of discovering new high-temperature superconductors that diverge from the copper-based paradigm1-3 carries profound implications for elucidating mechanisms behind superconductivity and may also enable new applications4-8. Here, our investigation reveals that application of pressure effectively suppresses the spin and charge order in trilayer nickelate La4Ni3O10-δ single crystals, leading to the emergence of superconductivity with a maximum critical temperature (Tc) of around 30 K at 69.0 GPa. The DC susceptibility measurements confirm a substantial diamagnetic response below Tc, indicating the presence of bulk superconductivity with a volume fraction exceeding 80%. In the normal state, we observe a "strange metal" behavior, characterized by a linear temperature-dependent resistance extending up to 300 K. Furthermore, the layer-dependent superconductivity observed hints at a unique interlayer coupling mechanism specific to nickelates, setting them apart from cuprates in this regard. Our findings provide crucial insights into the fundamental mechanisms underpinning superconductivity, while also introducing a new material platform to explore the intricate interplay between the spin/charge order, flat band structures, interlayer coupling, strange metal behavior and high-temperature superconductivity.

Motivation & Objective

• Motivate exploration of nickelate superconductivity beyond copper-based paradigms.
• Demonstrate pressure as a tool to suppress spin/charge order and reveal superconductivity in La4Ni3O10-δ.
• Characterize the superconducting state and its bulk nature under high pressure.

Proposed method

• Synthesize trilayer La4Ni3O10-δ single crystals.
• Apply high pressure up to 69.0 GPa to induce superconductivity.
• Measure DC magnetic susceptibility to assess diamagnetic response and bulk superconductivity (>80% volume fraction).
• Probe normal-state transport to identify strange metal behavior with linear-T resistivity up to 300 K.
• Analyze layer-dependent superconductivity to infer interlayer coupling mechanisms.

Experimental results

Research questions

• RQ1 Can pressure suppress spin and charge order in La4Ni3O10-δ to reveal superconductivity?
• RQ2 What is the maximum Tc achievable under pressure and at what pressure does it occur?
• RQ3 Does the superconducting state show bulk characteristics and how does interlayer coupling manifest?
• RQ4 What normal-state transport behavior accompanies the superconducting phase?
• RQ5 How does layer dependence inform the mechanism of superconductivity in nickelates?

Key findings

• Superconductivity emerges under pressure with a maximum Tc around 30 K at 69.0 GPa.
• DC susceptibility shows a substantial diamagnetic response indicating bulk superconductivity with volume fraction >80%.
• Normal-state transport exhibits strange metal behavior with linear temperature dependence of resistance up to 300 K.
• Layer-dependent superconductivity suggests a unique interlayer coupling mechanism in nickelates not typical of cuprates.