Phys.org September 16, 2024
Inhomogeneities crucially influence the properties of quantum materials, yet methods that can measure them remain limited and can access only a fraction of relevant observables. However, complementary techniques that can resolve higher-order correlations are needed to elucidate the nature of the inhomogeneities. And local tunnelling probes are often effective only far below the critical temperature. An international team of researchers (Germany, USA – Brookhaven, Harvard University, Cornell University, Stony Brook University, Switzerland, UK) developed a two-dimensional terahertz spectroscopy method to measure Josephson plasmon echoes from an interlayer superconducting tunnelling resonance in a near-optimally doped cuprate. The technique allowed them to study the multidimensional optical response of the interlayer Josephson coupling in the material and disentangle intrinsic lifetime broadening from extrinsic inhomogeneous broadening for interlayer superconducting tunnelling. They found that inhomogeneous broadening persisted up to a substantial fraction of the critical temperature, above which this was overcome by the thermally increased lifetime broadening… read more. Open Access TECHNICAL ARTICLEÂ
Phase-matching resolves individual plasmon nonlinearities. Credit: Nature Physics, 16 September 2024