相关论文: Nonlinear phononics in Bi$_2$Te$_3$ nanoscale thin…

Nonlinear processes involving frequency-mixing of light fields set the basis for ultrafast coherent spectroscopy of collective modes in solids. In certain semimetals and semiconductors, generation of coherent phonon modes can occur by a…

We investigate coherent lattice dynamics in optimally doped YBa$_2$Cu$_3$O$_{7-\delta}$ driven by ultrashort ($\sim$ 12 fs) near infrared (NIR) and near ultraviolet (NUV) pulses. Transient reflectivity experiments, performed at room…

Information technology demands high-speed optoelectronic devices, but going beyond the one terahertz (THz) barrier is challenging due to the difficulties associated with generating, detecting, and processing high-frequency signals. Here, we…

The excitation and detection of coherent phonons has given unique insights into condensed matter, in particular for materials with strong electron-phonon coupling. We report a study of coherent phonons in the layered charge density wave…

Phononic properties are commonly studied by calculating force constants using the density functional theory (DFT) simulations. Although DFT simulations offer accurate estimations of phonon dispersion relations or thermal properties, but for…

Raman measurements of a Fano-type surface phonon mode associated with Dirac surface states (SS) in Bi2Se3 topological insulator thin films allowed an unambiguous determination of the electron-phonon coupling strength in Dirac SS as a…

Using $\approx$40 fs ultrashort laser pulses, we investigate the picosecond acoustic response from a prototypical phase change material, thin Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) films with various thicknesses. After excitation with a 1.53…

Cuprates are promising candidates for study in developing higher temperature superconductors. A thorough understanding of a material's phonon modes enables further investigation of its emergent properties, however, no complete reference of…

We use first-principles density-functional calculations to determine the frequency shift of the A$'_1$-${\bf K}$ phonon (Raman D band) in monolayer graphene, as a function of the charge doping. A detailed DFT study on the electron-phonon…

We have studied the polarization dependence of coherent phonons in the topological insulator Bi2Te3. Using polarization-dependent femtosecond pump-probe spectroscopy, we measured coherent phonons as a function of angle when the pump and…

Phonons are quantized vibrations of a crystal lattice that play a crucial role in understanding many properties of solids. Density functional theory (DFT) provides a state-of-the-art computational approach to lattice vibrations from…

Phonon dispersions of one typical three-dimensional topological insulator Bi$_{2}$Se$_{3}$ have been studied within density functional theory. The soft modes of two acoustic branches along the $Z$$-$$F$ and $\Gamma$$-$$F$ directions within…

Collective excitations such as magnons and polar phonons provide natural access to the terahertz (THz) regime, but efficient generation and tunability remain elusive. Multiferroic BiFeO3 combines both orders at room temperature, offering a…

We report time- and angle-resolved photoemission spectroscopy measurements on the topological insulator Bi2Se3. We observe oscillatory modulations of the electronic structure of both the bulk and surface states at a frequency of 2.23 THz…

High-order nonlinear light-matter interactions in gases enable generation of x-ray and attosecond light pulses, metrology, and spectroscopy. Optical nonlinearities in solid-state materials are particularly interesting for combining optical…

Electron-phonon interactions (EPIs) represent a fundamental cornerstone of condensed matter physics, commanding persistent attention due to their pivotal role in driving novel quantum phenomena within low-dimensional materials. Here, we…

Selective excitation of coherent high-amplitude vibrations of atoms in a solid can induce exotic nonequilibrium states, in which the character of interactions between electronic, magnetic and lattice degrees of freedom is considerably…

Manipulating magnetism at the THz timescale in atomically thin ferromagnets by exploiting the interactions of spins with optical phonon modes presents an innovative idea for THz spintronics and magnonics. Utilizing the coupling of phonon…

Here, we investigate phonon mode- and electron band-selective electron-phonon couplings in centrosymmetric 1T$'$-MoTe$_2$ using time- and angle-resolved photoemission spectroscopy combined with frequency-domain analysis. Femtosecond…

We report on the impulsive generation of coherent optical phonons in CdTe0.68Se0.32 nanocrystallites embedded in a glass matrix. Pump probe experiments using femtosecond laser pulses were performed by tuning the laser central energy to…