The emergent properties of quantum materials, such as symmetry-broken phases and associated spectral gaps, can be effectively manipulated by ultrashort photon pulses. Impulsive optical excitation generally results in a complex non-equilibrium electron and lattice dynamics that involves multiple processes on distinct timescales, and a common conception is that for times shorter than about 100 fs the gap in the electronic spectrum is not seriously affected by lattice vibrations. Here, we directly monitor the photo-induced collapse of the spectral gap in a canonical charge-density-wave material, blue bronze Rb0.3MoO3. We find that ultra-fast (about 60 fs) vibrational disordering due to efficient hot-electron energy dissipation quenches the gap significantly faster than the typical structural bottleneck time corresponding to one half-cycle oscillation (about 315 fs) of the coherent charge-density-wave amplitude mode. This result not only demonstrates the importance of incoherent lattice motion in the photo-induced quenching of electronic order, but also resolves the perennial debate about the nature of the spectral gap in a coupled electron-lattice system.
最近的超快磁敏测量[Phys. Rev. B 92，184429（2015）和Phys. Rev. B 96，184414（2017）]揭示了TbMnO $_3$中长程摆线自旋序在基本Mott-Hubbard间隙的光激发后的延迟熔化。这种从光激发载流子到自旋自由度的能量缓慢转移背后的微观机制仍然难以捉摸，不为人所知。在这里，我们解决这个问题相结合的椭圆偏振光谱，超快宽带光谱和从头计算。在光激发时，我们观察到一个复杂的集体响应的出现，这是由于高能量的相干光学声子耦合到平衡电荷密度。这种响应先于磁序熔化，被解释为反Jahn Teller极化子形成的指纹。我们建议，在一个长寿命的自陷态的电荷本地化阻碍了磁振子和其他自旋翻转机制的发射，导致能量从电荷转移到自旋系统介导的晶格的重组。此外，我们提供的证据与铁电相变的声子模式的相干激发。
Ultrafast surface melting of orbital order in La0.5Sr1.5MnO4
Aarhus University（奥胡斯大学）；Le Mans Université（勒芒大学）；ALBA Synchrotron Light Source（阿尔巴同步辐射光源）；ShanghaiTech University（上海科技大学）；University of Oxford（牛津大学）；Swiss Light Source, Paul Scherrer Institut（瑞士微子源，保罗谢尔研究所）
High-harmonic generation during ultrafast melting of a Mott insulating state
University of Tokyo（东京大学）；Institute of Solid States Physics, University of Tokyo（东京大学固体物理研究所）；Institute for Materials Research, Tohoku University（东北大学材料科学研究所）；RIKEN（理化学研究所）；Nagoya Institute of Technology（名古屋工业大学）；National Institute of Advanced Industrial Science and Technology（产业技术综合研究所）；Nihon University（日本大学）
Persistent short-range charge correlations revealed by ultrafast melting of electronic order in YBa$_2$Cu$_3$O$_{6+x}$
Linac Coherent Light Source, SLAC National Accelerator Laboratory（直线相干光源，SLAC国家加速器实验室）；Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory and Stanford University（斯坦福材料能源科学研究所，SLAC国家加速器实验室和斯坦福大学）
Momentum-Selective Electron and Spin Dynamics under Ultrafast Photoexcitation
CPHT, CNRS, École polytechnique, Institut Polytechnique de Paris（法国高等理工学院）；Institut für Theoretische Physik, Universität Hamburg（汉堡大学理论物理研究所）；European X-Ray Free-Electron Laser Facility（欧洲X射线自由电子激光设施）；The Hamburg Centre for Ultrafast Imaging（汉堡超快成像中心）；Collège de France（法兰西学院）
Ultrafast Stiffening of the Lattice Potential and Metastable State Formation in 1$T$-TiSe$_2$
Central South University（中南大学）；Hunan University of Science and Technology（湖南科技大学）；Beijing Academy of Quantum Information Sciences（北京量子信息科学研究院）；Uppsala University（乌普萨拉大学）
Nonthermal melting and density wave instability coupled to the lattice in La$_4$Ni$_3$O$_{10}$
Central South University（中南大学）；Fudan University（复旦大学）；Shanghai Research Center for Quantum Sciences（上海量子科学研究中心）；Hefei National Laboratory（合肥国家实验室）；New Cornerstone Science Laboratory（新基石科学研究院）；Institute of Theoretical Physics, Chinese Academy of Sciences（中国科学院理论物理研究所）
Columbia University（哥伦比亚大学）；University of Washington（华盛顿大学）；Istituto CNR di Scienze e Tecnologie Chimiche (CNR-SCITEC)（意大利国家研究委员会化学科学与技术研究所）；University of Perugia（佩鲁贾大学）；National Institute for Materials Science（国立材料研究所）；Prince Mohammad Bin Fahd University（穆罕默德·本·法赫德国王大学）；Sungkyunkwan University（成均馆大学）
Role of Phase Fluctuation in Dynamic Competition Between Charge Order and Superconductivity in Cuprates
Massachusetts Institute of Technology（麻省理工学院）；Max Planck POSTECH/Korea Research Initiative, Center for Complex Phase of Materials（马普POSTECH/韩国研究倡议复杂物相中心）；Harvard University（哈佛大学）；University of Toronto（多伦多大学）；Pohang Accelerator Laboratory, Pohang University of Science and Technology（浦项加速器实验室，浦项科技大学）；Photon Science Center, Pohang University of Science and Technology（光子科学中心，浦项科技大学）；Department of Physics, Pohang University of Science and Technology（浦项科技大学物理系）；Canadian Light Source（加拿大光源）
Clustering-Enhanced Time- and Angle-Resolved Photoemission Study of LaTe$_3$: Absence of a Photoinduced Secondary CDW in the Electronic Structure
Aarhus University（奥胡斯大学）；CNR, Consiglio Nazionale delle Ricerche, Istituto officina dei materiali（意大利国家研究委员会材料研究所）；Central Laser Facility, STFC Rutherford Appleton Laboratory（STFC鲁瑟福阿普尔顿实验室中央激光设施）；SUPA, School of Physics and Astronomy, University of St Andrews（圣安德鲁斯大学物理与天文学学院）；Stanford University（斯坦福大学）；Diamond Light Source Ltd（钻石光源有限公司）；Princeton University（普林斯顿大学）；Department of Physics, Indian Institute of Technology Guwahati（印度理工学院古瓦哈提分校物理系）
Distinct amplitude mode dynamics upon resonant and off-resonant excitation across the charge density wave energy gap in LaTe3 investigated by time- and angle-resolved photoemission spectroscopy
Institute for Solid State Physics, The University of Tokyo（东京大学固体物理研究所）；Geballe Laboratory for Advanced Materials and Department of Applied Physics, Stanford University（斯坦福大学先进材料盖巴尔实验室与应用物理系）；Faculty of Physics, University of Duisburg-Essen（杜伊斯堡-埃森大学物理学院）
Correlation-Driven Ballistic Exciton Expansion in a Moiré Bose-Fermi Mixture
Purdue University（普渡大学）；Max Planck Institute for the Structure and Dynamics of Matter（马普物质结构与动力学研究所）；University of Washington（华盛顿大学）；National Institute for Materials Science（国立材料研究所）；RWTH Aachen University（亚琛工业大学）
Wigner polarons reveal Wigner crystal dynamics in a monolayer semiconductor
University of Maryland（马里兰大学）；ETH Zürich（苏黎世联邦理工学院）；Universität Heidelberg（海德堡大学）；Brookhaven National Laboratory（布鲁克海文国家实验室）；National Institute for Materials Science（物质材料研究机构）；University of Wisconsin-Madison（威斯康星大学麦迪逊分校）
