1. Photoinduced Enhancement of the Charge Density Wave Amplitude
- Author
-
Singer, A, Patel, SKK, Kukreja, R, Uhlíř, V, Wingert, J, Festersen, S, Zhu, D, Glownia, JM, Lemke, HT, Nelson, S, Kozina, M, Rossnagel, K, Bauer, M, Murphy, BM, Magnussen, OM, Fullerton, EE, and Shpyrko, OG
- Subjects
cond-mat.str-el ,Mathematical Sciences ,Physical Sciences ,Engineering ,General Physics - Abstract
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.
- Published
- 2016