Structural origins of the infamous "Low Temperature Orthorhombic" to "Low Temperature Tetragonal" phase transition in high-Tc cuprates

Abstract

We undertake a detailed high-resolution diffraction study of a novel plain band insulator, La${}_2$MgO${}_4$, which may be viewed as a structural surrogate system of the undoped end-member of the high-T${}_c$ superconductors, La${}_{2-x-y}$A${}_x^{2+}$RE${}_y^{3+}$CuO${}_4$ (A = Ba, Sr, RE= Rare Earth). We find that La${}_2$MgO${}_4$ exhibits the infamous low-temperature orthorhombic (LTO) to low-temperature tetragonal (LTT) phase transition that has been linked to the suppression of superconductivity in a variety of underdoped cuprates, including the well known La${}_{2-x}$Ba${}_x$CuO${}_4$ ($x=0.125$). Furthermore, we find that the LTO-to-LTT phase transition in La${}_2$MgO${}_4$ occurs for an octahedral tilt angle in the 4 ${}^{\circ }$ to 5 ${}^{\circ }$ range, similar to that which has previously been identified as a critical tipping point for superconductivity in these systems. We show that this phase transition, occurring in a system lacking spin correlations and competing electronic states such as charge-density waves and superconductivity, can be understood by simply navigating the density-functional theory ground-state energy landscape as a function of the order parameter amplitude. This result calls for a careful re-investigation of the origins of the phase transitions in high-T${}_c$ superconductors based on the hole-doped, $n=1$ Ruddelsden-Popper lanthanum cuprates.

6 pages, 4 figures

References in corpus (14)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Striped superconductors: How the cuprates intertwine spin, charge and superconducting orders
• Dynamical layer decoupling in a stripe-ordered, high T_c superconductor
• Cuprate superconductors as viewed through a striped lens
• Crystal structure and high-field magnetism of La2CuO4
• High-temperature superconductors: underlying physics and applications
• Properties of charge density waves in La${}_{2-x}$Ba${}_x$CuO${}_4$
• Effect of the electronic charge gap on LO bond-stretching phonons in undoped La${}_2$CuO${}_4$ calculated using LDA+U
• Ubiquitous Charge Order Correlations in High-Temperature Superconducting Cuprates
• Superconductivity from charge order in cuprates
• Reinvestigation of crystal symmetry and fluctuations in La${}_2$CuO${}_4$

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