Laser-driven Ultrafast Dynamics of a Fractional Quantum Hall System

Fuente: arXiv
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Main Authors: Kirmani, Ammar, Fauseweh, Benedikt, Zhu, Jian-Xin
Format: Preprint
Published: 2025
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author Kirmani, Ammar
Fauseweh, Benedikt
Zhu, Jian-Xin
author_facet Kirmani, Ammar
Fauseweh, Benedikt
Zhu, Jian-Xin
contents Fractional quantum Hall (FQH) systems are strongly interacting electron systems with topological order. These systems are characterized by novel ground states, fractionally charged and neutral excitations. The neutral excitations are dominated by a low-energy collective magnetoroton mode. Here we derive and use a quasi-one-dimensional model to investigate the ultrafast nonequilibrium dynamics of a laser-driven FQH system within a two-Landau-level approximation. As opposed to the traditional and synthetic bilayers, our model accounts for interactions where electrons can scatter from one Landau-level to another. By performing exact time evolution of the system, we create an out-of-equilibrium state following the laser pulse that shows rich physics. Our calculations show the presence of non-trivial excited modes. One of these modes is electromagnetically active and represent density oscillations of \emph{magnetoplasmon} mode. Another mode is identified by evaluating the overlap of the initial state and the out-of-equilibrium state following the laser pulse with a quadrupole operator. This mode is analogous to the chiral-graviton mode for FQH systems recently measured in experiments [Nature {\bf 628}, 78 (2024)]. Our results show that a linearly-polarized pulse field can excite the graviton mode when inter-Landau level scattering occurs.
format Preprint
id arxiv_https___arxiv_org_abs_2502_04622
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Laser-driven Ultrafast Dynamics of a Fractional Quantum Hall System
Kirmani, Ammar
Fauseweh, Benedikt
Zhu, Jian-Xin
Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
Fractional quantum Hall (FQH) systems are strongly interacting electron systems with topological order. These systems are characterized by novel ground states, fractionally charged and neutral excitations. The neutral excitations are dominated by a low-energy collective magnetoroton mode. Here we derive and use a quasi-one-dimensional model to investigate the ultrafast nonequilibrium dynamics of a laser-driven FQH system within a two-Landau-level approximation. As opposed to the traditional and synthetic bilayers, our model accounts for interactions where electrons can scatter from one Landau-level to another. By performing exact time evolution of the system, we create an out-of-equilibrium state following the laser pulse that shows rich physics. Our calculations show the presence of non-trivial excited modes. One of these modes is electromagnetically active and represent density oscillations of \emph{magnetoplasmon} mode. Another mode is identified by evaluating the overlap of the initial state and the out-of-equilibrium state following the laser pulse with a quadrupole operator. This mode is analogous to the chiral-graviton mode for FQH systems recently measured in experiments [Nature {\bf 628}, 78 (2024)]. Our results show that a linearly-polarized pulse field can excite the graviton mode when inter-Landau level scattering occurs.
title Laser-driven Ultrafast Dynamics of a Fractional Quantum Hall System
topic Mesoscale and Nanoscale Physics
Strongly Correlated Electrons
url https://arxiv.org/abs/2502.04622