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

The ability to efficiently control charge and spin in the cuprate high-temperature superconductors is crucial for fundamental research and underpins technological development. Here, we explore the tunability of magnetism, superconductivity, and crystal structure in the stripe phase of the cuprate La2-xBaxCuO4, with x = 0.115 and 0.135, by employing temperature-dependent (down to 400 mK) muon-spin rotation and AC susceptibility, as well as X-ray scattering experiments under compressive uniaxial stress in the CuO2 plane. A sixfold increase of the three-dimensional (3D) superconducting critical temperature Tc and a full recovery of the 3D phase coherence is observed in both samples with the application of extremely low uniaxial stress of similar to 0.1 GPa. This finding demonstrates the removal of the well-known 1/8-anomaly of cuprates by uniaxial stress. On the other hand, the spin-stripe order temperature as well as the magnetic fraction at 400 mK show only a modest decrease under stress. Moreover, the onset temperatures of 3D superconductivity and spin-stripe order are very similar in the large stress regime. However, strain produces an inhomogeneous suppression of the spin-stripe order at elevated temperatures. Namely, a substantial decrease of the magnetic volume fraction and a full suppression of the low-temperature tetragonal structure is found under stress, which is a necessary condition for the development of the 3D superconducting phase with optimal Tc. Our results evidence a remarkable cooperation between the long-range static spin-stripe order and the underlying crystalline order with the three-dimensional fully coherent superconductivity. Overall, these results suggest that the stripe-and the SC order may have a common physical mechanism. Significance Understanding the degree to which charge-stripe, spin-stripe, and superconducting orders compete/coexist is paramount for elucidating the microscopic pairing mechanism in the cuprate high-temperature superconductors. We explore the tunability of magnetism, superconductivity, and crystal structure in the stripe phase of the cuprate La2-xBaxCuO4, by employing complementary techniques under compressive uniaxial stress in the CuO2 plane. Our results show a sixfold increase of the three-dimensional (3D) superconducting critical temperature Tc with the application of extremely low uniaxial stress of <^>0.1 GPa and evidence a remarkable cooperation between the static spin-stripe order and the underlying crystalline order with the 3D superconductivity. Our results suggest that the underlying pairing mechanisms are essentially the same in the alternative superconducting states with and without spin-stripe order.