Related papers: Non-ohmicity and energy relaxation in diffusive 2D…
We have used symmetric normal metal-insulator-superconductor (NIS) tunnel junction pairs, known as SINIS structures, for ultrasensitive thermometry in the temperature range 50 - 700 mK. By Joule heating the electron gas and measuring the…
Here we examine the role of the amorphous insulating substrate in the thermal relaxation in thin NbN, InO$_x$, and Au/Ni films at temperatures above 5 K. The studied samples are made up of metal bridges on an amorphous insulating layer…
Electron-hole pairs in semiconductors are essential for solar cells and fast electronic circuitry, but the competition between carrier transport and relaxation into heat limits the efficiency and speed. Here we use ultrafast electron…
The energy relaxation channels of hot electrons far from thermal equilibrium in a degenerate two-dimensional electron system are investigated in transport experiments in a mesoscopic three-terminal device. We observe a transition from two…
Considering screeening of electron scattering interactions in terms of the finite-temperature STLS theory and solving the linearized Boltzmann equation (with no appeal to a relaxation time approximation), we present a theoretical analysis…
The temporal evolution of quantal Joule heating of 2D electrons in GaAs quantum well placed in quantizing magnetic fields is studied using a difference frequency method. The method is based on measurements of the electron conductivity…
We report on near normal infrared reflectivity spectra of ~550 nm thick films made of cosputtered transition metal nanograins and SiO2 in a wide range of metal fractions. Co0.85(SiO2)0.15,with conductivity well above the percolation…
We theoretically study the relaxation of electron orbital states of a double quantum dot system due to two-phonon processes. In particular, we calculate how the relaxation rates depend on the separation distance between the quantum dots,…
While the optical properties of thin metal films are well understood in the visible and near-infrared range, little has been done in the mid- and far-infrared region. Here we investigate ultra-thin gold films prepared on Si(111)(7 x 7) in…
To better understand the many effects of temperature on the optical properties of metals, we experimentally and theoretically quantify the electron vs. phonon contributions to the thermoreflectance spectra of gold. We perform a series of…
We present a detailed theoretical study of the ultrafast quasiparticle relaxation dynamics observed in normal metals and heavy fermion materials with femtosecond time-resolved optical pump-probe spectroscopy. For normal metals, a nonthermal…
The effects of thermal diffuse scattering on the transmission and eventual diffraction of highly accelerated electrons are investigated with a method that incorporates the frozen phonon approximation to the exact numerical solution of the…
The femtosecond optical pump-probe technique was used to study dynamics of photoexcited electrons and coherent optical phonons in transition metals Zn and Cd as a function of temperature and excitation level. The optical response in time…
In this study a method for calculation of the electron-phonon scattering rate in semiconductor structures with one-dimensional electron gas is developed. The energy uncertainty of electrons is taken into account.
We analyze the heat power $P$ between electrons and phonons in thin metallic films deposited on free-standing dielectric membranes in a temperature range in which the phonon gas has a quasi two-dimensional distribution. The quantization of…
We compute the transient dynamics of phonons in contact with high energy "hot" charge carriers in 12 polar and non-polar semiconductors, using a first-principles Boltzmann transport framework. For most materials, we find that the decay in…
We have made a detailed temperature-dependent photoemission study of VO_2/TiO_2(001) thin films, which show a metal-insulator transition at \sim 300 K. Clean surfaces were obtained by annealing the films in an oxygen atmosphere. Spectral…
The strength of the electron-phonon coupling parameter and its evolution throughout a solid's phase diagram often determines phenomena such as superconductivity, charge- and spin-density waves. Its experimental determination relies on the…
We present a simple and efficient approximation to the electron-phonon scattering rate suitable for high-throughput screening of candidate materials for thermoelectric devices, based on electronic transport. The method is applied to…
We investigate temperature dependent transport properties of two-dimensional p-GaAs systems taking into account both hole-phonon and hole-impurity scattering effects. By analyzing the hole mobility data of p-GaAs in the temperature range 10…