Probing (sub)nanoscale ferrons in an electron microscope

Abstract

Ferrons are collective excitations of polarization fluctuations that can enable terahertz communications and quantum transduction due to long propagation lengths. Although ferrons have been experimentally demonstrated in van der Waals ferroelectrics and relaxor ferroelectrics, there is no direct (sub)nanoscale experimental evidence of ferrons in three-dimensional ferroelectrics. Here, we detect two types of ferrons, Higgs and pseudo-Goldstone, at the (sub)nanoscale in lead titanate by measuring vibrational signals due to polarization fluctuations. By harnessing momentum transfer in electron energy loss spectroscopy (EELS), we directly distinguish between soft-phonons and ferrons. We observe that the Higgs mode originates from the soft optical phonon parallel to the polar axis, whereas the pseudo-Goldstone mode originates from the soft optical phonon perpendicular to the polarization axis. Together with Landau theory, Raman spectroscopy measurements, and EELS, we observe that Higgs group velocities, in the bulk limit, are eight times greater than those of out-of-plane soft phonons and the pseudo-Goldstone ferrons have group velocities six times greater than in-plane soft phonons due to long-range dipole interactions. We further show that the domain size confinement effects lead to doubling of the respective bulk ferron group velocities, reaching up to approximately 15 km per second (almost 15 times higher than the out-of-plane soft phonon modes). Overall, this study opens a pathway to the detection of ferrons in three-dimensional ferroelectrics with domain engineering as a promising avenue for terahertz communication and transduction.

AutoRASOR: Autonomous Rapid Scanning Electron Microscope Operator
Kevin Zhang, Mohammad Taha, Rafael Espinosa Castañeda +7
arXiv18 Sep 2026PreprintarXiv licenceFull textCondensed matterarXiv
Model-constrained nanoscale 3D cathodoluminescence reconstruction of InGaN LEDs via coupled electron–photon transport
Sentong Wang, Lihong Zhu, Peixin Li +4
Optics Express22 Oct 2026Peer-reviewedPublisher termsCondensed matterCrossref
Probing the wave-vector gap in nanoscale magnonics
Ondřej Wojewoda, Samer Kurdi, Toeno van der Sar +3
arXiv11 Oct 2026PreprintCC BY 4.0Full textCondensed matterarXiv
Electron Wavefronts Capture Nanoscale Movies of Hypersound at Surfaces
Johannes Otto, Leon Brauns, Benjamin Schroeder +1
arXiv23 Oct 2026PreprintarXiv licenceFull textApplied physics & instrumentation Condensed matterarXiv
Nanoscale chemical engineering of Ti3C2Tx MXene multilayers through in situ electron beam irradiation in a TEM
Ayoub Benmoumen, Marie-Laure David, Noé Condé +7
arXiv19 Oct 2026PreprintCC BY-NC-SA 4.0Full textCondensed matterarXiv

Cite

BibTeX RIS

BibTeX

@misc{manna2026probing,
  title = {{Probing (sub)nanoscale ferrons in an electron microscope}},
  author = {Mahir Manna and Fei Yang and Shayantan Chaudhuri and Sourav Shenoy and Guo-Dong Zhao and Mohit Tanwani and Surya Prakash Reddy and Patrick J. Hays and Sriram Sankar and Cauê de Souza Coutinho Nogueira and Srilekshmi Muraleedharan and Xin Xu and Sujit Das and Katherine Inzani and Long-Qing Chen and Sandhya Susarla},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.13625},
  eprint = {2609.13625},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.13625},
  note = {CC BY 4.0},
}

RIS

TY  - UNPB
TI  - Probing (sub)nanoscale ferrons in an electron microscope
AU  - Mahir Manna
AU  - Fei Yang
AU  - Shayantan Chaudhuri
AU  - Sourav Shenoy
AU  - Guo-Dong Zhao
AU  - Mohit Tanwani
AU  - Surya Prakash Reddy
AU  - Patrick J. Hays
AU  - Sriram Sankar
AU  - Cauê de Souza Coutinho Nogueira
AU  - Srilekshmi Muraleedharan
AU  - Xin Xu
AU  - Sujit Das
AU  - Katherine Inzani
AU  - Long-Qing Chen
AU  - Sandhya Susarla
PY  - 2026
DA  - 2026/09/12
PB  - arXiv
DO  - 10.48550/arxiv.2609.13625
UR  - https://arxiv.org/abs/2609.13625
AB  - Ferrons are collective excitations of polarization fluctuations that can enable terahertz communications and quantum transduction due to long propagation lengths. Although ferrons have been experimentally demonstrated in van der Waals ferroelectrics and relaxor ferroelectrics, there is no direct (sub)nanoscale experimental evidence of ferrons in three-dimensional ferroelectrics. Here, we detect two types of ferrons, Higgs and pseudo-Goldstone, at the (sub)nanoscale in lead titanate by measuring vibrational signals due to polarization fluctuations. By harnessing momentum transfer in electron energy loss spectroscopy (EELS), we directly distinguish between soft-phonons and ferrons. We observe that the Higgs mode originates from the soft optical phonon parallel to the polar axis, whereas the pseudo-Goldstone mode originates from the soft optical phonon perpendicular to the polarization axis. Together with Landau theory, Raman spectroscopy measurements, and EELS, we observe that Higgs group velocities, in the bulk limit, are eight times greater than those of out-of-plane soft phonons and the pseudo-Goldstone ferrons have group velocities six times greater than in-plane soft phonons due to long-range dipole interactions. We further show that the domain size confinement effects lead to doubling of the respective bulk ferron group velocities, reaching up to approximately 15 km per second (almost 15 times higher than the out-of-plane soft phonon modes). Overall, this study opens a pathway to the detection of ferrons in three-dimensional ferroelectrics with domain engineering as a promising avenue for terahertz communication and transduction.
ER  -

Abstract

Related

Cite