Phonon-assisted formation of an itinerant electronic density wave

Electronic instabilities drive ordering transitions in condensed matter. Despite many advances in the microscopic understanding of the ordered states, a more nuanced and profound question often remains unanswered: how do the collective excitations influence the electronic order formation? Here, we e...

Full description

Saved in:
Bibliographic Details
Published in:arXiv.org 2020-12
Main Authors: Li, Jiaruo, Oleg Yu Gorobtsov, Patel, Sheena K K, Nelson, Hua, Gregory, Benjamin, Shabalin, Anatoly G, Hrkac, Stjepan, Wingert, James, Cela, Devin, Glownia, James M, Chollet, Matthieu, Zhu, Diling, Rajasekhar Medapalli, Fullerton, Eric E, Shpyrko, Oleg G, Singer, Andrej
Format: Article
Language:English
Subjects:
Condensed matter physics
Femtosecond pulses
High temperature
Low temperature
Order parameters
Phonons
Spin density waves
Temperature dependence
Thin films
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Electronic instabilities drive ordering transitions in condensed matter. Despite many advances in the microscopic understanding of the ordered states, a more nuanced and profound question often remains unanswered: how do the collective excitations influence the electronic order formation? Here, we experimentally show that a phonon affects the spin density wave (SDW) formation after an SDW-quench by femtosecond laser pulses. In a thin film, the temperature-dependent SDW period is quantized, allowing us to track the out-of-equilibrium formation path of the SDW precisely. By exploiting its persistent coupling to the lattice, we probe the SDW through the transient lattice distortion, measured by femtosecond X-ray diffraction. We find that within 500 femtoseconds after a complete quench, the SDW forms with the low-temperature period, directly bypassing a thermal state with the high-temperature period. We argue that a momentum-matched phonon launched by the quench changes the formation path of the SDW through the dynamic pinning of the order parameter.
ISSN:2331-8422