Intertwined nematic and d-wave superconductive orders in optimally doped La_1.84Sr_0.16CuO₄ thin films

The anisotropy of the superconducting state and superconducting fluctuations in the CuO₂ plane is directly related to the superconducting mechanism of copper oxide superconductors and is therefore pivotal for understanding high-temperature superconductivity. Here, we integrated the high-precision angle-resolved resistivity measurement with a rotatable in-plane magnetic field to systematically study the angular dependence of superconducting fluctuations in optimally doped La_1.84Sr_0.16CuO₄ (LSCO) thin films. By independently controlling the directions of the current and the magnetic field, we are able to isolate the magneto-resistivity contributed by the superconducting vortex motion and distinguish excitations from nematic superconductivity and d-wave superconductive order based on their respective C ₂ and C ₄ symmetries. Signatures of two intertwined superconductive orders are also evident in the measured angular dependence of the critical current. A T-B phase diagram of different types of superconducting fluctuations is determined. These findings are closely related to other intriguing phenomena, such as pair density wave, charge density wave, and local pairing.