Pektas, Yigit ErtacArtun, E. CanBerker, A. Nihat2024-06-232024-06-23202310960-07791873-2887https://doi.org/10.1016/j.chaos.2023.114159https://hdl.handle.net/20.500.12469/5796Artun, Erbil Can/0000-0002-9624-3124; Berker, A/0000-0002-5172-2172A spin-glass system with a smooth or fractal outer surface is studied by renormalization-group theory, in bulk spatial dimension d = 3. Independently varying the surface and bulk random-interaction strengths, phase diagrams are calculated. The smooth surface does not have spin-glass ordering in the absence of bulk spin-glass ordering and always has spin-glass ordering when the bulk is spin-glass ordered. With fractal (d > 2) surfaces, a sponge is obtained and has surface spin-glass ordering also in the absence of bulk spin-glass ordering. The phase diagram has the only-surface-spin-glass ordered phase, the bulk and surface spin-glass ordered phase, and the disordered phase, and a special multicritical point where these three phases meet. All spin-glass phases have distinct chaotic renormalization-group trajectories, with distinct Lyapunov and runaway exponents which we have calculated.eninfo:eu-repo/semantics/openAccessSpin-glass chaosSurface chaosSpontaneous and driven chaosChaos on fractalsLyapunov ExponentsChaos multicritical pointArticle176WOS:00109945190000110.1016/j.chaos.2023.1141592-s2.0-85173276871Q1Q1