Charge and spin density wave gaps in La₄Ni₃O₁₀ measured by point contact spectroscopy

The metallic tri-layer nickelate La₄Ni₃O₁₀ develops CDW and SDW orders at temperatures below ~150 K. The two orders are seen to be coupled where the magnitude of the propagation vector corresponding to CDW is twice that corresponding to SDW. We have performed temperature and magnetic field dependent point-contact spectroscopy experiments on a single crystal of La₄Ni₃O₁₀ and observed evidence of spectral gaps corresponding to the two orders. The gap corresponding to the SDW order, identified through its strong magnetic field dependence, is larger in amplitude and displays a temperature dependence that is different from the CDW order. The results can be understood within a layer-selective picture where the SDW and CDW orders develop in different layers of the tri-layer system.