Strain-Tuning of 2D and 3D Charge-Density Waves in High-Temperature Superconducting YBa$_{2}$Cu$_{3}$O$_{\rm{y}}$

Abstract

Uniaxial pressure experiments in underdoped YBa$_{2}$Cu$_{3}$O$_{\rm{y}}$ provide an efficient approach to the control of the competition between charge-density waves (CDWs) and superconductivity. It can enhance the correlation volume of ubiquitous short-range CDW correlations and above a critical value, even induce a long-range CDW order otherwise only accessible through the suppression of superconductivity by large magnetic fields. Here we use x-ray diffraction with access to large areas of reciprocal space to study the evolution of long- and short-range CDWs with in-plane strains and as a function of doping. This further allows us to precisely monitor in-situ the structural changes induced by uniaxial pressurization of the crystals for a precise strain estimation in measurements up to $-0.85 \%$ compression. Interestingly, we uncover direct evidence for a competition between long- and short-range CDWs and show that the long-range CDW modulation remains incommensurate at all investigated strains and temperatures, showing neither signs of discommensurations nor a pair-density wave component at $\lambda_{\rm{PDW}} = 2\lambda_{\rm{CDW}}$ below $T_c$. We discuss the impact of structural disorder and the relationship of our findings to previous reports on nematicity in high-temperature superconducting cuprates. More generally, our results underscore the potential of strain tuning as a powerful tool for probing and manipulating competing orders in quantum materials.Comment: I. Vinograd and S. M. Souliou contributed equally to this wor