Attosecond nanoscopy of electron dynamics instrongly correlated materials

Introduction

In 1929, one year after the formulation of his world-famous equation, Paul Dirac wrote that "the fundamental laws (…) of a large part of physics and the whole of chemistry are thus completely known, (…) but lead to equations that are too complex to be solved". While Dirac was referring to analytical solutions to his equation, numerical approaches have made tremendous progress over the past century. Nonetheless, the so-called strongly correlated materials continue to defy a common experimental and computational access to some of their intriguing exotic properties in solids.

Project Overview

In this proposal, I will investigate correlated transition-metal oxides, which undergo a phase transition upon external perturbation, such as temperature, pressure, strain, or laser excitation.

Experimental Development

I will develop a unique table-top ultrafast soft-X-ray absorption and holographic imaging experiment. The measurements will follow the attosecond to picosecond dynamic switching between metallic and insulating phases after laser excitation of transition metal oxides with element-specific absorption measurements.

Spatial Resolution

Simultaneously, the experiment will spatially resolve the ultrafast emerging nanometer texture of the phase transition. The unprecedented measurement of attosecond nanoscale dynamics will enable us to unambiguously identify the mechanism and ultimate speed of phase transitions.

Hypothesis Testing

I will use the fundamental insight from attosecond nanoscopy to test the hypothesis that structural and electronic insulator-metal transitions (IMTs) coexist and can be steered through both sample engineering and attosecond light-field control. This will pave the way towards PHz oxide electronics.

Future Applications

Controlling the currently absent spatial uniformity of phase transitions on the nanoscale and the concomitant order-of-magnitude resistivity changes are key ingredients to guide transition-metal oxides towards their long-heralded usage in future oxide electronics as thin-film transistors. This advancement will finally enable ReRAM memory to enter high-volume manufacturing.