Control of Magnetic and Topological Orders with a DC Electric Field

TL;DR

This paper proposes a theoretical method to manipulate magnetic and topological phases in insulating magnets using DC electric fields, potentially enabling control over quantum states in various magnetic materials.

Contribution

It introduces a new approach to control magnetic and topological orders via electric fields, especially effective in weak Mott insulators and near quantum critical points.

Findings

Electric fields enhance magnetic exchange interactions along their direction.

Application of strong DC electric fields can induce quantum spin liquids and Haldane-gap states.

Strategy applicable to cold atomic systems and low-frequency AC electric fields.

Abstract

We theoretically propose a new route to control magnetic and topological orders in a broad class of insulating magnets with a DC electric field. We show from the strong-coupling expansion that magnetic exchange interactions along the electric-field direction are generally enhanced in Mott insulators. We demonstrate that several magnetic or topological ordered phases such as quantum spin liquids and Haldane-gap states can be derived if we apply a strong enough DC electric field to typical frustrated or low-dimensional magnets. Our proposal is effective especially for weak Mott insulators and magnets in the vicinity of quantum critical points, and would also be applicable for magnets under low-frequency AC electric fields such as terahertz laser pulses. A similar strategy of controlling exchange interactions can also be utilized in cold atomic systems.