Atomic-scale imaging of emergent order at a magnetic-field-induced Lifshitz transition

TL;DR

This study uses atomic-scale imaging to reveal how a magnetic field induces a Lifshitz transition and charge order in Sr$_3$Ru$_2$O$_7$, providing microscopic insights into quantum phase transitions.

Contribution

It offers the first detailed microscopic imaging of electronic structure changes during a magnetic-field-induced Lifshitz transition in a correlated material.

Findings

Electronic structure is strongly $C_2$ symmetric at zero field.

Magnetic field induces a Lifshitz transition and charge-stripe order.

Changes in electronic structure are tracked via quasi-particle interference imaging.

Abstract

The phenomenology and radical changes seen in materials properties traversing a quantum phase transition has captivated condensed matter research over past decades. Strong electronic correlations lead to novel electronic ground states, including magnetic order, nematicity and unconventional superconductivity. Providing a microscopic model for these requires detailed knowledge of the electronic structure in the vicinity of the Fermi energy, promising a complete understanding of the physics of the quantum critical point. Here, we demonstrate such a measurement at the surface of Sr$_3$Ru$_2$O$_7$. Our results show that, even in zero field, the electronic structure is strongly $C_2$ symmetric and that a magnetic-field drives both a Lifshitz transition and induces a charge-stripe order. We track the changes of the electronic structure as a function of field via quasi-particle interference imaging at ultralow temperatures. Our results provide a complete microscopic picture of the field-induced changes of the electronic structure across the Lifshitz transition.