Coherent Structural Dynamics of a Prototypical Charge-Density-Wave-to-Metal Transition

Using femtosecond time-resolved x-ray diffraction, we directly monitor the coherent lattice dynamics through an ultrafast charge-density-wave-to-metal transition in the prototypical Peierls system K0.3MoO3 over a wide range of relevant excitation fluences. While in the low fluence regime we directly follow the structural dynamics associated with the collective amplitude mode; for fluences above the melting threshold of the electronic density modulation we observe a transient recovery of the periodic lattice distortion. We can describe these structural dynamics as a motion along the coordinate of the Peierls distortion triggered by the prompt collapse of electronic order after photoexcitation. The results indicate that the dynamics of a structural symmetry-breaking transition are determined by a high-symmetry excited state potential energy surface distinct from that of the initial low-temperature state.


Published in:
Physical Review Letters, 113, 2
Year:
2014
Publisher:
College Pk, American Physical Society
ISSN:
0031-9007
Laboratories:




 Record created 2014-10-23, last modified 2018-09-13


Rate this document:

Rate this document:
1
2
3
 
(Not yet reviewed)