Related papers: Energy-gap dynamics of superconducting NbN thin fi…
The terahertz (THz) properties of ZrN thin films grown with CMOS-techniques on industry-standard 300 mm silicon wafers are investigated in order to explore their superconducting behavior. The films have thicknesses ranging from 18 to 48 nm,…
Recent optical studies in c-axis oriented superconducting MgB$_2$ films indicate that the electron-phonon coupling is weak [tu01]. We reinforce this conclusion by examining the raw reflectance data; its frequency dependence is incompatible…
We calculate nonequilibrium quasiparticle and phonon distributions for a number of widely-used low transition temperature thin-film superconductors under constant, uniform illumination by sub-gap probe and pair-breaking signal photons…
The ability to simulate realistically the electronic structure of superconducting materials is important to understand and predict various properties emerging in both the superconducting topological and spintronics realms. We introduce a…
Lortz et al. [Phys. Rev. B 73, 024512 (2006)] have utilized specific heat and resistivity measurements as "thermal spectroscopies" to deconvolve the spectrum of the electron-phonon interaction in YB$_6$ assuming a major role of the low…
The ultrafast relaxation and recombination dynamics of photogenerated electrons and holes in epitaxial graphene are studied using optical-pump Terahertz-probe spectroscopy. The conductivity in graphene at Terahertz frequencies depends on…
Femtosecond pump-probe studies show that carrier dynamics in MgB2 films is governed by the sub-ps electron-phonon (e-ph) relaxation present at all temperatures, the few-ps e-ph process well pronounced below 70 K, and the sub-ns…
We describe a model for photon absorption by superconducting tunnel junctions in which the full energy dependence of all the quasiparticle dynamic processes is included. The model supersedes the well-known Rothwarf-Taylor approach, which…
In time-resolved photoemission experiments, more than one electron can be emitted from the solid by a single ultra-short pulse. We theoretically demonstrate how correlations between the momenta of outgoing electrons relate to time-dependent…
We measured the THz reflectance properties of a high quality epitaxial thin film of the Fe-based superconductor BaFe$_{1.84}$Co$_{0.16}$As$_2$ with T$_c$=22.5 K. The film was grown by pulsed laser deposition on a DyScO$_3$ substrate with an…
Dynamics of depletion and recovery of superconducting state in La2-xSrxCuO_4 thin films is investigated utilizing optical pump-probe and optical pump - THz probe techniques as a function of temperature and excitation fluence. The absorbed…
It is now well known that the properties of the disordered s wave superconductors can deviate significantly from the prediction of standard Bardeen-Cooper-Schrieffer (BCS) theory. By measuring the temperature dependence of the resonance…
Simultaneous measurements of transient transmission and reflectivity were performed in the unintentionally doped InN film to reveal ultrafast optical bleaching and its recovery behavior under intense laser irradiation. The optical bleaching…
We calculate the critical temperature $T_c$ and the superconducting energy gaps $\Delta_n$ of a thin film superconductor system, where $\Delta_n$ is the superconducting energy gap of the $n$-th subband. Since the quantization of both the…
We systematically explore the exquisiteness of Bardeen-Cooper-Schriefer(BCS) theory where the BCS-type electron-phonon interaction is unambiguously reinforced as the only viable superglue in cuprate superconductors because phonon-induced…
In nanocrystalline Nb films, the superconducting Tc decreases with a reduction in the average particle size below 20nm. We correlate the decrease in Tc with a reduction in the superconducting energy gap measured by point contact…
We investigate the terahertz conductivity of conventional superconductors in Voigt and Faraday magneto-optical configurations. First, we review theoretical approaches describing the fundamental processes of suppression of superconductivity…
We employ optical pump-THz probe spectroscopy to chart the ultrafast superconductivity suppression in NbN over a broad range of excitation fluences. Our measurements uncover a pronounced lengthening of the superconductivity quenching time…
We measured the terahertz (THz) complex conductivity of Ca doped YBa_{2}Cu_{3}O_{7-\delta} thin films in the frequency range of 0.1 to 3 THz (3 to 100 cm^{-1}) and at a temperature range of 20 to 300 K. The films were measured using both…
We report on the charge carrier dynamics of superconducting titanium nitride (TiN) in the frequency range 90 - 510 GHz (3 - 17 cm-1). The experiments were perfomed on a 18 nm thick TiN film with a critical temperature of 3.4 K. Measurements…