Related papers: Ultrafast Raman thermometry in driven YBa$_2$Cu$_3…
Lead sulfide is an important semiconductor that has found technological applications for over a century. Raman spectroscopy, a standard tool for the investigation and characterization of semiconductors, has limited application to this…
The equilibrium optical phonons of graphene are well characterized in terms of anharmonicity and electron-phonon interactions, however their non-equilibrium properties in the presence of hot charge carriers are still not fully explored.…
We describe a simple AC susceptometer built in-house that can be used to make high-resolution measurements of the magnetic susceptibility of high-temperature superconductors in an undergraduate physics lab. Our system, cooled using liquid…
The thermal conductivity of ultraclean YBa$_2$Cu$_3$O$_7$ was measured at very low temperature in magnetic fields up to 13 T. The temperature and field dependence of the electronic heat conductivity show that two widespread assumptions of…
We report a combined experimental and theoretical investigation of near resonance light scattering from a high-density and ultracold atomic $^{87}$Rb gas. The atomic sample, having a peak density $\sim 5\cdot10^{13}$ atoms/cm$^{3}$,…
The a-axis optical properties of a detwinned single crystal of YBa_2Cu_3O_6.50 in the ortho II phase (Ortho II Y123, T_c= 59 K) were determined from reflectance data over a wide frequency range (70 - 42 000 cm^-1) for nine temperature…
We present measurements of the transient photoconductivity in pentacene single crystals using optical-pump THz-probe spectroscopy. We have measured the temperature and fluence dependence of the mobility of the photoexcited charge carriers…
We present a theory for the time-resolved optical spectroscopy of high-temperature superconductors at high excitation densities with strongly anisotropic electron-phonon coupling. A signature of the strong coupling between the out-of-plane,…
We report the observation of low-frequency modes in the Raman spectra of thin-film superlattices of the high-temperature superconductor YBa$ _{2} $Cu$ _{3} $O$ _{7-\delta} $ and various manganite perovskites. Our study shows that these…
We have performed polarized Raman scattering measurements on the newly discovered superconductor Ba$_{2}$Ti$_{2}$Fe$_{2}$As$_{4}$O$_{2}$ ($T_c = 21$ K). We observe seven out of eight Raman active modes, with frequencies in good accordance…
Electronic Raman scattering from high- and low-energy excitations was studied as a function of temperature, extent of hole doping, and energy of the incident photons in Bi_2Sr_2CaCu_2O_{8 \pm \delta} superconductors. For underdoped…
A fundamental understanding of phonon transport in stanene is crucial to predict the thermal performance in potential stanene-based devices. By combining first-principle calculation and phonon Boltzmann transport equation, we obtain the…
The thermal and electrical transport properties of single-crystalline LaBe$_{13}$ have been investigated by specific-heat ($C$) and electrical-resistivity ($\rho$) measurements. The specific-heat measurements in a wide temperature range…
Femtosecond dynamics of coherent optical phonons in GeTe/Sb$_{2}$Te$_{3}$ superlattices (SLs), a new class of semiconductor SLs with three different states, have been investigated by using a reflection-type pump-probe technique at various…
Ultrafast time-resolved optical spectroscopy in high-temperature superconductors enables the direct real-time measurement of non-equilibrium quasiparticle recombination dynamics. In addition, it also gives detailed information about the…
We present a systematic study of the interplay between lattice parameters and the energy of the optical phonons as well as the antiferromagnetic coupling strength, $J$, in the high-$T_{\text{c}}$ superconducting cuprate…
We report on the dynamics of coherent phonons in semimetal 1T'-MoTe2 using femtosecond pump-probe spectroscopy. On an ultrafast sub-picosecond time scale at room temperature, a low frequency and long-lifetime shear phonon mode was observed…
We report on time-resolved optical and terahertz ultrafast spectroscopy of charge-carrier dynamics in the room-temperature antiferromagnetic semiconductor $\alpha $-MnTe. By optically pumping the system with 1.55 eV photons at room…
Resonant optical excitation of apical oxygen vibrational modes in the normal state of underdoped YBa2Cu3O6+x induces a transient state with optical properties similar to those of the equilibrium superconducting state. Amongst these, a…
We present results of electronic Raman-scattering experiments in differently doped Y-123. In B2g symmetry, an analysis of the data in terms of a memory function approach is presented and dynamical relaxation rates $\Gamma(\omega,T)$ and…