Nonequilibrium Magnetic Oscillation with Cylindrical Vector Beams

TL;DR

This paper proposes a novel optical method using cylindrical vector beams to measure magnetic oscillations in materials without disturbing their magnetic order, enabling new insights into electronic structures under various conditions.

Contribution

It introduces a theoretical approach utilizing azimuthal cylindrical vector beams to measure magnetic oscillations in a way that preserves magnetic order, unlike traditional static magnetic field methods.

Findings

The method leverages the unique focusing property of CV beams to generate a pure longitudinal magnetic field.

It exploits the different relaxation timescales of conduction electrons and magnetic moments.

Applicable to metals under ultra-high pressure conditions in diamond anvil cells.

Abstract

Magnetic oscillation is a generic property of electronic conductors under magnetic fields and widely appreciated as a useful probe of their electronic band structure, i.e., the Fermi surface geometry. However, the usage of the strong static magnetic field makes the measurement insensitive to the magnetic order of the target material. That is, the magnetic order is anyhow turned into a forced ferromagnetic one. Here we theoretically propose an experimental method of measuring the magnetic oscillation in a magnetic-order-resolved way by using the azimuthal cylindrical vector (CV) beam, an example of topological lightwaves. The azimuthal CV beam is unique in that when focused tightly, it develops a pure longitudinal magnetic field. We argue that this characteristic focusing property and the discrepancy in the relaxation timescale between conduction electrons and localized magnetic moments allow us to develop the nonequilibrium analog of the magnetic oscillation measurement. Our optical method would be also applicable to metals the under ultra-high pressure of diamond anvil cells.