Ultrafast Optical Control of Magnetic Order and Fermi Surface Topology at a Quantum Critical Point

TL;DR

This paper theoretically explores how ultrafast light pulses can dynamically control magnetic order and Fermi surface topology in a Kondo system near quantum criticality, enabling phase transitions and electronic state manipulation.

Contribution

It introduces a theoretical framework showing light can induce magnetic order and topological Fermi surface changes in a quantum critical Kondo system, revealing new pathways for material control.

Findings

Light pulses can dehybridize Kondo screening.

Induction of magnetic order from paramagnetic state.

Observation of a dynamic Lifshitz transition changing Fermi surface topology.

Abstract

Designing material properties on demand has important implications to potential future technological applications. While theoretically it is always possible to tune various intrinsic energy scales, there are fundamental limitations to this approach in experiment. In recent years, ultrafast spectroscopy has evolved as a promising tool to use light to dynamically induce non-trivial electronic states of matter. Here we theoretically investigate light pulse driven dynamics in a Kondo system close to quantum criticality. We show, that light can dehybridize the local Kondo screening and induce magnetic order out of a previously paramagnetic state. We demonstrate that, depending on the laser pulse field parameters, it is possible to deconfine the Kondo singlet and thereby induce second order phase transition to a dynamically ordered state, as well as a dynamic Lifshitz transition that changes the Fermi surface topology from hole- to electron-like.