Photoinduced Enhancement of the Charge Density Wave Amplitude

Photoinduced Enhancement of the Charge Density Wave Amplitude

WoS Article

Symmetry breaking and the emergence of order is one of the most fascinating phenomena in condensed matter physics. It leads to a plethora of intriguing ground states found in antiferromagnets, Mott insulators, superconductors, and density-wave systems. Exploiting states of matter far from equilibrium can provide even more striking routes to symmetry-lowered, ordered states. Here, we demonstrate for the case of elemental chromium that moderate ultrafast photoexcitation can transiently enhance the charge-density-wave (CDW) amplitude by up to 30% above its equilibrium value, while strong excitations lead to an oscillating, large-amplitude CDW state that persists above the equilibrium transition temperature. Both effects result from dynamic electron-phonon interactions, providing an efficient mechanism to selectively transform a broad excitation of the electronic order into a well-defined, long-lived coherent lattice vibration. This mechanism may be exploited to transiently enhance order parameters in other systems with coupled degrees of freedom.

Symmetry breaking and the emergence of order is one of the most fascinating phenomena in condensed matter physics. It leads to a plethora of intriguing ground states found in antiferromagnets, Mott insulators, superconductors, and density-wave systems. Exploiting states of matter far from equilibrium can provide even more striking routes to symmetry-lowered, ordered states. Here, we demonstrate for the case of elemental chromium that moderate ultrafast photoexcitation can transiently enhance the charge-density-wave (CDW) amplitude by up to 30% above its equilibrium value, while strong excitations lead to an oscillating, large-amplitude CDW state that persists above the equilibrium transition temperature. Both effects result from dynamic electron-phonon interactions, providing an efficient mechanism to selectively transform a broad excitation of the electronic order into a well-defined, long-lived coherent lattice vibration. This mechanism may be exploited to transiently enhance order parameters in other systems with coupled degrees of freedom.

Chromium; Superconductivity; Charge Density Waves; Manganites

Chromium; Superconductivity; Charge Density Waves; Manganites

SINGER, A.; PATEL, S.; KUKREJA, R.; UHLÍŘ, V.; WINGERT, J.; FESTERSEN, S.; ZHU, D.; GLOWNIA, J.; LEMKE, H.; NELSON, S.; KOZINA, M.; ROSSNAGEL, K.; BAUER, M.; MURPHY, B.; MAGNUSSEN, O.; FULLERTON, E.; SHPYRKO, O.

2017

20.03.2016

1079-7114

Physical Review Letters

117

5

United States of America

056401-1

056401-6

6