2018/06/07 by Alfred Zong, Anshul Kogar, Ya-Qing Bie +21 · 6 citations
Materials Science · Physics and Astronomy · #Advanced Chemical Physics Studies #Amplitude #Charge density wave #Coherence (philosophical gambling strategy) #Condensed matter physics #Excitation #Laser #Optics #Organic and Molecular Conductors Research #Phase (matter) #Phase transition #Physics #Pulse (music) #Quantum mechanics #Spectroscopy and Quantum Chemical Studies #State of matter #Symmetry (geometry) #Thermal equilibrium #Topological defect #Ultrashort pulse #cond-mat.mtrl-sci #cond-mat.str-el
paper · pdf · doi:10.1038/s41567-018-0311-9
published as Nature Physics 15, 27 (2019)
arxiv created 2018/06/07 · openalex publication_date 2018/10/12 · arxiv updated 2019/02/28 · openalex created_date 2020/11/23 · openalex updated_date 2026/07/23
Upon excitation with an intense ultrafast laser pulse, a symmetry-broken ground state can undergo a non-equilibrium phase transition through pathways dissimilar from those in thermal equilibrium. Determining the mechanism underlying these photo-induced phase transitions (PIPTs) has been a long-standing issue in the study of condensed matter systems. To this end, we investigate the light-induced melting of a unidirectional charge density wave (CDW) material, LaTe3. Using a suite of time-resolved probes, we independently track the amplitude and phase dynamics of the CDW. We find that a quick (∼ 1 ps) recovery of the CDW amplitude is followed by a slower reestablishment of phase coherence. This longer timescale is dictated by the presence of topological defects: long-range order (LRO) is inhibited and is only restored when the defects annihilate. Our results provide a framework for understanding other PIPTs by identifying the generation of defects as a governing mechanism.