Probing quantum geometry with two-dimensional nonlinear optical spectroscopy

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Froese, Paul, Hirsbrunner, Mark R., Kim, Yong Baek
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911037870047232
author Froese, Paul
Hirsbrunner, Mark R.
Kim, Yong Baek
author_facet Froese, Paul
Hirsbrunner, Mark R.
Kim, Yong Baek
contents Recent studies have shown that the nonlinear optical response of crystalline systems is fundamentally a quantum geometric property. In this work, we propose two-dimensional coherent spectroscopy (2DCS), which measures the nonlinear conductivity as a function of two independent frequencies using two time-delayed light pulses, as a probe of quantum geometry. We show how the two-frequency second-order nonlinear conductivity, which is naturally measured by 2DCS, decomposes into distinct quantum geometric contributions. We identify a term arising from the multi-band quantum connection that does not appear in linear response, and show that it can be measured in isolation by considering specific polarizations and enforcing time-reversal symmetry. We explore this finding via model calculations for transition metal dichalcogenides and Sr$_2$RuO$_4$. Through these examples, we demonstrate how 2DCS enables study of the quantum connection, providing a way to compare the quantum geometry of different materials. We also show that one can gain rough momentum-resolved knowledge of the quantum geometry by varying the chemical potential.
format Preprint
id arxiv_https___arxiv_org_abs_2506_05462
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Probing quantum geometry with two-dimensional nonlinear optical spectroscopy
Froese, Paul
Hirsbrunner, Mark R.
Kim, Yong Baek
Mesoscale and Nanoscale Physics
Recent studies have shown that the nonlinear optical response of crystalline systems is fundamentally a quantum geometric property. In this work, we propose two-dimensional coherent spectroscopy (2DCS), which measures the nonlinear conductivity as a function of two independent frequencies using two time-delayed light pulses, as a probe of quantum geometry. We show how the two-frequency second-order nonlinear conductivity, which is naturally measured by 2DCS, decomposes into distinct quantum geometric contributions. We identify a term arising from the multi-band quantum connection that does not appear in linear response, and show that it can be measured in isolation by considering specific polarizations and enforcing time-reversal symmetry. We explore this finding via model calculations for transition metal dichalcogenides and Sr$_2$RuO$_4$. Through these examples, we demonstrate how 2DCS enables study of the quantum connection, providing a way to compare the quantum geometry of different materials. We also show that one can gain rough momentum-resolved knowledge of the quantum geometry by varying the chemical potential.
title Probing quantum geometry with two-dimensional nonlinear optical spectroscopy
topic Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2506.05462