Classical Analog of Quantum Light Cones in 1D and 2D Dipole Systems

Abstract

AbstractThe speed at which the magnetic perturbation or information propagates along a chain of classical dipoles is discussed. While in the quantum information counterpart for long‐range interacting spins, where the speed of propagation of the information plays a paramount role, it is not strictly clear whether a light cone exists or not, numerical evidence that interacting dipoles do posses a linear light cone shortly after a perturbation takes place in classical systems is provided. Specifically, a power‐law expansion occurs which is followed by a linear propagation of the associated perturbation. As opposed to the quantum case, and in analogy with the so‐called speed of gravity problem, it is found that the speed of propagation of information can be arbitrarily large in the classical context. While it is true that quantum information outperforms any classical treatment regarding many processes and properties, it is shown that for the case of spin buffers, classical chains of dipoles can indeed play a role as auxiliary tools in both quantum communications and processing.