Designing the stripe-ordered cuprate phase diagram through uniaxial-stress

Area of Science:

• Condensed Matter Physics
• Materials Science
• Superconductivity Research

Background:

• Controlling charge and spin in cuprate high-temperature superconductors is vital for fundamental science and technology.
• The stripe phase in cuprates, like La[Formula: see text]Ba[Formula: see text]CuO[Formula: see text], exhibits complex interplay between magnetism, superconductivity, and crystal structure.
• The 1/8-anomaly in cuprates presents a significant challenge in understanding their superconducting mechanisms.

Purpose of the Study:

• To investigate the tunability of magnetism, superconductivity, and crystal structure in the stripe phase of La[Formula: see text]Ba[Formula: see text]CuO[Formula: see text] under uniaxial stress.
• To explore the impact of compressive uniaxial stress on the 3D superconducting critical temperature ([Formula: see text]) and phase coherence.
• To examine the relationship between spin-stripe order and superconductivity, and to probe the common physical mechanisms potentially underlying both.

Main Methods:

• Utilized temperature-dependent muon-spin rotation and AC susceptibility experiments (down to 400 mK).
• Employed X-ray scattering experiments under compressive uniaxial stress applied in the CuO[Formula: see text] plane.
• Studied two samples of La[Formula: see text]Ba[Formula: see text]CuO[Formula: see text] with [Formula: see text] = 0.115 and 0.135.

Main Results:

• A sixfold increase in the 3D superconducting critical temperature ([Formula: see text]) and full recovery of 3D phase coherence were observed with minimal uniaxial stress (~0.1 GPa).
• The application of stress effectively removed the 1/8-anomaly in the cuprates.
• Spin-stripe order temperature and magnetic fraction showed only a modest decrease under stress, with onset temperatures for 3D superconductivity and spin-stripe order becoming similar at high stress. Strain induced inhomogeneous suppression of spin-stripe order and a full suppression of the low-temperature tetragonal structure.

Conclusions:

• Uniaxial stress demonstrates a powerful method for enhancing superconductivity and overcoming anomalies in cuprates.
• The results reveal a strong cooperation between long-range spin-stripe order, crystalline order, and 3D coherent superconductivity.
• The findings strongly suggest that stripe order and superconducting order may share a common underlying physical mechanism.