Isolated Stripes on 18-Leg Cylinders Advance Understanding of High-Temperature Superconductivity

Spin-charge stripes represent a key ordering phenomenon in high-temperature superconductors, yet remain difficult to study due to limitations in computational modelling. Tizian Blatz, Sebastian Paeckel, Ulrich Schollwöck, Fabian Grusdt, and Annabelle Bohrdt investigate the formation of these long, isolated stripes using a novel computational approach. The team employs the density-matrix renormalization group algorithm to model cylindrical strips significantly wider than previous simulations, allowing them to explore a broader range of electron and hole doping levels. This work demonstrates that the observed variation in stripe filling fractions likely arises from the fundamental physics of a single stripe, and reveals two distinct regimes governing stripe formation, each presenting unique challenges for experimental observation. By connecting the complex behaviour of the striped phase to its microscopic origins, this research provides new insights into the nature of high-temperature superconductivity.

The team employed the density-matrix renormalization group algorithm to model cylindrical strips significantly wider than previous simulations, allowing them to explore a broader range of electron and hole doping levels. This work demonstrates that observed variation in stripe filling fractions likely arises from the fundamental physics of a single stripe, and reveals two distinct regimes governing stripe formation, each presenting unique challenges for experimental observation. By connecting the complex behaviour of the striped phase to its microscopic origins, this research provides new insights into the nature of high-temperature superconductivity.,.

Stripes Formed and Studied in Cylindrical Geometry

Scientists investigated the formation of spin-charge stripes, a low-temperature phenomenon in high-temperature superconductors, by employing the density-matrix renormalization group algorithm to map out ground states. This work addresses the challenges posed by finite-size effects common in numerical studies of these complex materials, offering a complementary perspective to typical finite-doping phase diagrams. The team engineered an unconventional experimental setup using cylindrical strips with 18 legs, significantly wider than those used in previous investigations, to allow for the study of long, isolated stripes. This geometry enables accurate mapping of stripe formation without the proximity of other phases and minimizes finite-size effects. To facilitate ground-state searches in this unusual geometry, researchers developed a tailored matrix-product states mapping, inspired by one-dimensional systems with periodic boundary conditions. This innovative mapping shifts the computational complexity, enabling the study of systems comparable in effort to conventional simulations with lower aspect ratios.,.

Isolated Stripes Govern Superconductor Doping Regimes

Scientists have achieved a detailed understanding of stripe formation in high-temperature superconductors, focusing on the behaviour of these stripes independent of finite-size effects that typically complicate numerical studies. The research team employed the density-matrix renormalization group algorithm to investigate the ground states of cylindrical systems, specifically utilizing an 18-leg geometry significantly wider than previously explored, enabling the study of extended, isolated stripes. This approach accurately maps the range of possible stripe filling fractions for both electron and hole doping, confirming agreement with established results and suggesting that observed variations in filling are governed by the physics of a single stripe. The study reveals two distinct regimes governing stripe formation, a high-filling regime accurately described by a simplified squeezed-space model, and a low-filling regime characterized by the structure of individual dopant pairs. Measurements confirm that the pattern of partially filled stripes originates from the arrangement of these dopant pairs, representing the fundamental building blocks of both striped and superconducting phases.,.

Stripe Formation Regimes and Filling Fractions

This research delivers new insights into the behaviour of spin-charge stripes, a crucial low-temperature phenomenon observed in high-temperature superconductors. By employing the density-matrix renormalization group algorithm on a wider cylindrical geometry than previously used, scientists have mapped out the range of possible stripe filling fractions for both electron and hole-doped materials. The results confirm existing findings and demonstrate that observed variations in filling fractions likely stem from the fundamental physics governing a single stripe. Importantly, the team identified two distinct regimes in stripe formation, revealing that high-filling regimes can be understood using a simplified model, while low-filling regimes are characterized by the arrangement of individual dopant pairs. This microscopic understanding traces the complex behaviour of striped phases back to their basic constituents and highlights the challenges in observing these regimes experimentally.