Snapshots of cooperative atomic motions in the optical suppression of charge density waves

Autoren

Maximilian Eichberger
Hanjo Schäfer
Marina Krumova
Markus Beyer
Jure Demsar
Helmuth Berger
Gustavo Moriena
Germán Sciaini
RJ Dwayne Miller

DOI

10.1038/nature09539

eISSN

1476-4687

ISSN

0028-0836

Ausgabe der Veröffentlichung

7325

Zeitschrift

Nature

Sprache

en

Online publication date

2010

Paginierung

799 - 802

Datum der Veröffentlichung

2010

Status

Published

Herausgeber

Springer Science and Business Media LLC

Herausgeber URL

http://dx.doi.org/10.1038/nature09539

Datum der Datenerfassung

2023

Titel

Snapshots of cooperative atomic motions in the optical suppression of charge density waves

Ausgabe der Zeitschrift

468

Datenquelle: Crossref

Abstract

Macroscopic quantum phenomena such as high-temperature superconductivity, colossal magnetoresistance, ferrimagnetism and ferromagnetism arise from a delicate balance of different interactions among electrons, phonons and spins on the nanoscale. The study of the interplay among these various degrees of freedom in strongly coupled electron-lattice systems is thus crucial to their understanding and for optimizing their properties. Charge-density-wave (CDW) materials, with their inherent modulation of the electron density and associated periodic lattice distortion, represent ideal model systems for the study of such highly cooperative phenomena. With femtosecond time-resolved techniques, it is possible to observe these interactions directly by abruptly perturbing the electronic distribution while keeping track of energy relaxation pathways and coupling strengths among the different subsystems. Numerous time-resolved experiments have been performed on CDWs, probing the dynamics of the electronic subsystem. However, the dynamics of the periodic lattice distortion have been only indirectly inferred. Here we provide direct atomic-level information on the structural dynamics by using femtosecond electron diffraction to study the quasi two-dimensional CDW system 1T-TaS(2). Effectively, we have directly observed the atomic motions that result from the optically induced change in the electronic spatial distribution. The periodic lattice distortion, which has an amplitude of ∼0.1 Å, is suppressed by about 20% on a timescale (∼250 femtoseconds) comparable to half the period of the corresponding collective mode. These highly cooperative, electronically driven atomic motions are accompanied by a rapid electron-phonon energy transfer (∼350 femtoseconds) and are followed by fast recovery of the CDW (∼4 picoseconds). The degree of cooperativity in the observed structural dynamics is remarkable and illustrates the importance of obtaining atomic-level perspectives of the processes directing the physics of strongly correlated systems.

Addresses

Physics Department and Center of Applied Photonics and Zukunftskolleg, University of Konstanz, D-78457 Konstanz, Germany.

Autoren

Maximilian Eichberger
Hanjo Schäfer
Marina Krumova
Markus Beyer
Jure Demsar
Helmuth Berger
Gustavo Moriena
Germán Sciaini
RJ Dwayne Miller

DOI

10.1038/nature09539

eISSN

1476-4687

Externe Identifier

PubMed Identifier: 21107321

Open access

false

ISSN

0028-0836

Ausgabe der Veröffentlichung

7325

Zeitschrift

Nature

Sprache

eng

Medium

Print-Electronic

Online publication date

2010

Paginierung

799 - 802

Datum der Veröffentlichung

2010

Status

Published

Datum der Datenerfassung

2010

Titel

Snapshots of cooperative atomic motions in the optical suppression of charge density waves.

Sub types

Research Support, Non-U.S. Gov't
Journal Article

Ausgabe der Zeitschrift

468

Datenquelle: Europe PubMed Central

Abstract

Macroscopic quantum phenomena such as high-temperature superconductivity, colossal magnetoresistance, ferrimagnetism and ferromagnetism arise from a delicate balance of different interactions among electrons, phonons and spins on the nanoscale. The study of the interplay among these various degrees of freedom in strongly coupled electron-lattice systems is thus crucial to their understanding and for optimizing their properties. Charge-density-wave (CDW) materials, with their inherent modulation of the electron density and associated periodic lattice distortion, represent ideal model systems for the study of such highly cooperative phenomena. With femtosecond time-resolved techniques, it is possible to observe these interactions directly by abruptly perturbing the electronic distribution while keeping track of energy relaxation pathways and coupling strengths among the different subsystems. Numerous time-resolved experiments have been performed on CDWs, probing the dynamics of the electronic subsystem. However, the dynamics of the periodic lattice distortion have been only indirectly inferred. Here we provide direct atomic-level information on the structural dynamics by using femtosecond electron diffraction to study the quasi two-dimensional CDW system 1T-TaS(2). Effectively, we have directly observed the atomic motions that result from the optically induced change in the electronic spatial distribution. The periodic lattice distortion, which has an amplitude of ∼0.1 Å, is suppressed by about 20% on a timescale (∼250 femtoseconds) comparable to half the period of the corresponding collective mode. These highly cooperative, electronically driven atomic motions are accompanied by a rapid electron-phonon energy transfer (∼350 femtoseconds) and are followed by fast recovery of the CDW (∼4 picoseconds). The degree of cooperativity in the observed structural dynamics is remarkable and illustrates the importance of obtaining atomic-level perspectives of the processes directing the physics of strongly correlated systems.

Date of acceptance

2010

Autoren

Maximilian Eichberger
Hanjo Schäfer
Marina Krumova
Markus Beyer
Jure Demsar
Helmuth Berger
Gustavo Moriena
Germán Sciaini
RJ Dwayne Miller

Autoren-URL

https://www.ncbi.nlm.nih.gov/pubmed/21107321

DOI

10.1038/nature09539

eISSN

1476-4687

Ausgabe der Veröffentlichung

7325

Zeitschrift

Nature

Sprache

eng

Country

England

Paginierung

799 - 802

PII

nature09539

Datum der Veröffentlichung

2010

Status

Published

Datum, an dem der Datensatz öffentlich gemacht wurde

2011

Titel

Snapshots of cooperative atomic motions in the optical suppression of charge density waves.

Sub types

Journal Article
Research Support, Non-U.S. Gov't

Ausgabe der Zeitschrift

468

Datenquelle: PubMed

Snapshots of cooperative atomic motions in the optical suppression of charge density waves

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