Spontaneous symmetry breaking by charge stripes in the high-pressure phase of superconducting La(1.875)Ba(0.125)CuO(4)

TL;DR

This study demonstrates that charge stripe order in cuprate superconductors can spontaneously break lattice symmetry even when the crystal structure is symmetrized by high pressure, indicating an electronically-driven origin.

Contribution

It shows that charge stripe order persists under conditions where lattice symmetry is restored, highlighting the electronic nature of stripe formation in cuprates.

Findings

Charge stripe order exists despite restored four-fold symmetry.

Electronic stripe order can spontaneously break lattice symmetry.

High pressure does not suppress charge stripe order.

Abstract

In those cases where charge stripe order has been observed in cuprates, the crystal structure is such that the average rotational symmetry of the CuO2 planes is reduced from four-fold to two-fold. As a result, one could argue that the reduced lattice symmetry is essential to the existence of stripe order. We use pressure to restore the average four-fold symmetry in a single crystal of La(1.875)Ba(0.125)CuO(4), and show by x-ray diffraction that charge stripe order still occurs. Thus, electronically-driven stripe order can spontaneously break the lattice symmetry.