Browsing by Subject "electron"

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Electron mobility in monolayer WS2 encapsulated in hexagonal boron-nitride
(AIP Publishing, 2021-03-11) Wang, Yimeng; Sohier, Thibault; Watanabe, Kenji; Taniguchi, T; Verstraete, Matthieu J.; Tutuc, Emanuel
We report electron transport measurements in dual-gated monolayer WS2 encapsulated in hexagonal boron-nitride. Using gated Ohmic con- tacts that operate from room temperature down to 1.5 K, we measure the intrinsic conductivity and carrier density as a function of tempera- ture and gate bias. Intrinsic electron mobilities of 100 cm 2/(V s) at room temperature and 2000 cm2/(V s) at 1.5 K are achieved. The mobility shows a strong temperature dependence at high temperatures, consistent with phonon scattering dominated carrier transport. At low temperature, the mobility saturates due to impurity and long-range Coulomb scattering. First-principles calculations of phonon scattering in monolayer WS2 are in good agreement with the experimental results, showing we approach the intrinsic limit of transport in these two-dimensional layers.
Enhanced Phosphorescence in Dibenzophosphole Chalcogenide Mixed Crystal
(2011-06) Kabe, Ryota; Lynch, Vincent M.; Anzenbacher, Pavel; Lynch, Vincent M.
The single crystals of 9-phenyl-9-dibenzophosphole chalcogenides {oxide (1), sulfide (2) and selenide (3)} and a mixed crystal of 2 and 3 have been prepared and characterized by X-ray diffraction analysis. Several intermolecular interactions such as pi-pi and Se-H were observed in the mixed crystal of 2 and 3. The mixed crystal of 2 and 3 exhibited enhanced phosphorescence compared to the pure constituent crystal (2 or 3) at low temperature.
Plasma acceleration and cooling by strong laser field due to the action of radiation reaction force
(2008-12) Berezhiani, V. I.; Mahajan, S. M.; Yoshida, Z.; Mahajan, S. M
It is shown that for super intense laser pulses propagating in a hot plasma, the action of the radiation reaction force (appropriately incorporated into the equations of motion) causes strong bulk plasma motion with the kinetic energy raised even to relativistic values; the increase in bulk energy is accompanied by a corresponding cooling (intense cooling) of the plasma. The effects are demonstrated through explicit analytical calculations.
Relativistic Bi-Stability In A Plasma Beatwave Accelerator
(2004-06) Shvets, G.; Shvets, Gennady
Beatwave excitation of plasma waves is analyzed in the regime where relativistic corrections to the plasma frequency are important. It is shown that a long beatwave pulse can excite strong plasma waves in its wake even when the beatwave frequency is detuned from the electron plasma frequency. The wake is caused by the dynamic bi-stability of the nonlinear plasma wave if the beatwave amplitude exceeds the analytically calculated threshold. Two possible beatwave drivers are considered: intensity-modulated laser pulse and density-modulated electron beam. It is found that, due to the relativistic bi-stability, so portions of the driver may experience photon blue-shifting (for the laser driver) or electron acceleration (for the beam driver). In the latter case a combined accelerator/injector is envisioned.