Master 2: International Centre for Fundamental Physics
INTERNSHIP PROPOSAL
Laboratory name:Laboratoire de Physique des solides
CNRS identification code: UMB8502
Internship director’surname:David Le Bolloc’h/V. Jacques
E-mail:lebolloch@lps.u-psud.fr
Phone number:0169156057
Web page: https://www.equipes.lps.u-psud.fr/Lebolloch/
Internship location:Orsay
Thesis possibility after internship:
YES
Funding: YES/NO
If YES, which type of funding:
Sliding incommensurates. The role of dimensionality.
Interaction between pairs of quasiparticles may lead to three electronic ground states in
solids: Cooper pairs in superconductors, spin-density waves (SDWs) or charge-density waves
(CDWs). The CDW state is a common feature in solid which can coexist with SDW, like in
chromium, or can compete with superconductivity like in cuprates. The most spectacular property
of a CDW system is its ability to carry correlated charges when submitting the sample to an
external current. Above a threshold current indeed, an additional current is observed as well as a
strong resistivity noise containing well-defined frequencies. This is an evidence of the presence of
correlated charge carriers traveling through the system. This phenomenon received a considerable
interest for more than 35 years. However, the type of charge carriers and the mode of propagation
still remain incomplete.
We propose here to study the role of dimensionality in sliding CDW by using coherent
x-ray diffraction in synchrotrons. This technique allows us to observe phase shifts of the CDW
modulation and to observe those phase shifts in motion during sliding, showing their involvement
in the collective charges transport.
Two experiments are planned. The first experiment will be performed at the European
synchrotron (ESRF at Grenoble) in order to probe mesoscopic aspect of a sliding CDW. The
second one will be performed at the Soleil synchrotron to observe the out of equilibrium CDW
after a femtosecond laser pulse excitation.
[1 ] D Le Bolloc’h, V Jacques, N. Kirova, J Dumas, S Ravy, J Marcus, and F Livet. Observation of Correlations Up To
the Micrometer Scale in Sliding Charge-Density Waves. Physical Review Letters, 100, 096403 (2008).
[2] V Jacques, S Ravy, D Le Bolloc’h, E Pinsolle, M SauvageSimkin, and F Livet. Bulk Dislocation Core Dissociation
Probed by Coherent X Rays in Silicon. Physical Review Letters, 106, 065502 (2011).
[3] V. L. R. Jacques, D Le Bolloc’h, E Pinsolle, F E Picca, and S Ravy. Estimation of coherence properties of an
undulator-generated x-ray beam from near-field and far-field slit diffraction visibilities. Physical Review B, 86,
144117 (2012).
[4] E Pinsolle, N. Kirova, V L R Jacques, A A Sinchenko, and D Le Bolloch. Creep, Flow, and Phase Slippage
Regimes: An Extensive View of the Sliding ChargeDensity Wave Revealed by Coherent X-ray Diffraction. Physical
Review Letters, 109, 256402 (2012).
Condensed Matter Physics: YES
Quantum Physics:
YES/NO
Macroscopic Physics and complexity: YES/NO
Theoretical Physics:
YES/NO