Zlatko Papic " Weak ergodicity breaking, scars and superdiffusive energy transport in the PXP model" скачать в хорошем качестве

Zlatko Papic " Weak ergodicity breaking, scars and superdiffusive energy transport in the PXP model"

Universal nonequilibrium properties of isolated quantum systems are typically probed by studying transport of conserved quantities, such as charge or spin, while transport of energy has received considerably less attention. I will present results of our recent study [arXiv:2210.01146] of infinite-temperature energy transport in the kinetically-constrained PXP model describing Rydberg atom quantum simulators. The numerics in large systems reveal the existence of two distinct transport regimes. At moderate times, the energy-energy correlation function displays periodic oscillations due to families of eigenstates forming different representations of su(2) algebra, hidden within the spectrum. These families of eigenstates generalise the quantum many-body scarred states found in previous works and leave an imprint on the infinite-temperature energy transport. At later times, we observe a broad superdiffusive transport regime that we attribute to the proximity of a nearby integrable point. Intriguingly, strong deformations of the PXP model by the chemical potential do not restore diffusion, but instead lead to a stable superdiffusive exponent close to the Kardar-Parisi-Zhang value.