The Quantum Geometric Tensor in a Parameter Dependent Curved Space

TL;DR

This paper develops a quantum geometric tensor framework in a parameter-dependent curved space, unifying the quantum metric and Berry curvature, with applications to various anharmonic oscillator models.

Contribution

It introduces a novel quantum geometric tensor in curved space with parameter dependence, extending the concepts of quantum metric and Berry curvature.

Findings

Derived the quantum metric tensor using two methods.

Modified the Berry connection to transform as a proper connection.

Provided explicit examples with anharmonic oscillators in curved space.

Abstract

We introduce a quantum geometric tensor in a curved space with a parameter-dependent metric, which contains the quantum metric tensor as the symmetric part and the Berry curvature corresponding to the antisymmetric part. This parameter-dependent metric modifies the usual inner product, which induces modifications in the quantum metric tensor and Berry curvature by adding terms proportional to the derivatives with respect to the parameters of the determinant of the metric. The quantum metric tensor is obtained in two ways: By using the definition of the infinitesimal distance between two states in the parameter-dependent curved space and via the fidelity susceptibility approach. The usual Berry connection acquires an additional term with which the curved inner product converts the Berry connection into an object that transforms as a connection and density of weight one. Finally, we provide three examples in one dimension with a nontrivial metric: an anharmonic oscillator, a Morse-like potential, and a generalized anharmonic oscillator; and one in two dimensions: the coupled anharmonic oscillator in a curved space.