2019/02/26 by Alfred Zong, Pavel E. Dolgirev, Anshul Kogar +26 · 4 citations
Chemistry · Materials Science · Physics and Astronomy · #Advanced Thermodynamics and Statistical Mechanics #Charge density wave #Chemistry #Condensed matter physics #Excited state #Femtochemistry #Femtosecond #Laser #Laser-Matter Interactions and Applications #Materials science #Mechanical and Optical Resonators #Non-equilibrium thermodynamics #Observable #Optics #Organic and Molecular Conductors Research #Phase (matter) #Phase transition #Photoexcitation #Physics #Quantum mechanics #Slowdown #Spectroscopy and Quantum Chemical Studies #Statistical physics #Transition (genetics) #Ultrafast electron diffraction #Ultrashort pulse #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1103/physrevlett.123.097601
published in Physical Review Letters 123(9), 097601 (American Physical Society)
arxiv created 2019/02/26 · openalex publication_date 2019/08/29 · arxiv updated 2019/09/04 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Complex systems, which consist of a large number of interacting constituents, often exhibit universal behavior near a phase transition. A slowdown of certain dynamical observables is one such recurring feature found in a vast array of contexts. This phenomenon, known as critical slowing-down, is well studied mostly in thermodynamic phase transitions. However, it is less understood in highly nonequilibrium settings, where the time it takes to traverse the phase boundary becomes comparable to the timescale of dynamical fluctuations. Using transient optical spectroscopy and femtosecond electron diffraction, we studied a photoinduced transition of a model charge-density-wave (CDW) compound LaTe3. We observed that it takes the longest time to suppress the order parameter at the threshold photoexcitation density, where the CDW transiently vanishes. This finding can be captured by generalizing the time-dependent Landau theory to a system far from equilibrium. The experimental observation and theoretical understanding of dynamical slowing-down may offer insight into other general principles behind nonequilibrium phase transitions in many-body systems.