Geometry and speed of evolution for a spin-s system with long-range zz-type Ising interaction

TL;DR

This paper investigates the geometric properties and evolution speed of a spin-s system with long-range zz-type Ising interaction, analyzing the quantum state manifold, its curvature, and effects of external magnetic fields, with implications for experiments.

Contribution

It provides a detailed geometric analysis of the quantum state manifold for a long-range Ising spin system, including curvature and evolution speed, and explores effects of external magnetic fields.

Findings

The state manifold topology is a sphere.

The curvature relates to the evolution speed.

Conditions for minimal and maximal evolution speed are identified.

Abstract

We study the evolution of a spin-s system described by the long-range zz-type Ising interaction. The Fubini-Study metric of the quantum state manifold defined by this evolution is obtained. We explore the topology of this manifold and show that it corresponds to a sphere. Exploration of the Riemannian curvature allows us to determine the manifold geometry. Also we calculate the speed of evolution of the system and represent the curvature by means of this speed. This is important for an experimental measurement of the curvature. The conditions for achieving the minimal and maximal values of the speed of evolution are obtained. Also we examine the geometry of state manifold and speed of evolution of spin system in the thermodynamic limit. We propose the physical system of methane molecule for application of our considerations. Finally, we study the influence of an external magnetic field on the metric of state manifold and on the speed of evolution. In this case we obtain the conditions for achieving the minimal possible speed of evolution. For some predefined initial states the orientations of magnetic fields to reach the minimal and maximal values of the speed are found.