Two-photon interband transitions at critical points in semiconductors

1970 ◽  
Vol 70 (1) ◽  
pp. 21-38 ◽  
Author(s):  
A. R. Hassan
2005 ◽  
Vol 483-485 ◽  
pp. 409-412 ◽  
Author(s):  
L. Storasta ◽  
R. Aleksiejūnas ◽  
M. Sūdžius ◽  
Arunas Kadys ◽  
T. Malinauskas ◽  
...  

We applied four-wave mixing (FWM) technique for investigation of high temperaturechemical vapour deposition (HTCVD) grown 4H-SiC samples with different doping levels. The determined minority electron and hole mobilities in heavily doped crystals at doping densities of 1019 cm-3 were found to be equal to 116 and 52 cm2/Vs. In semi-insulating (SI) crystals, the ambipolar diffusion coefficient Da = 2.6 − 3.3 cm2/s and carrier lifetimes of 1.5 – 2.5 ns have been measured. Irradiation of SI crystals by 6 MeV electrons resulted in essential decrease of carrier lifetime down to ~ 100 ps and clearly revealed the defect-assisted carrier generation with respect to two-photon interband transitions before irradiation.


2021 ◽  
Author(s):  
Alvaro Jimenez-Galan ◽  
Rui Silva ◽  
Misha (Mikhail) Ivanov

Abstract The reconstruction of attosecond beating by interference of two-photon transitions (RABBIT) is one of the most widely used techniques for resolving ultrafast electronic dynamics in atomic and molecular systems. As it relies on the interference of photo-electrons in vacuum, similar interference has never been contemplated in the bulk of crystals. Using accurate numerical simulations in a realistic system, here we show that the interference of two-photon transitions can be recorded directly in the bulk of solids and read out with standard angle-resolved photo-emission spectroscopy. The phase of the RABBIT beating in the photoelectron spectra coming from the bulk of solids is sensitive to the relative phase of the Berry connection between bands and it experiences a shift of π as one of the quantum paths crosses a band. For resonant interband transitions, the amplitude of the RABBIT oscillation decays as the pump and probe pulses are separated in time due to electronic decoherence, providing a simple interferometric method to extract dephasing times.


Sign in / Sign up

Export Citation Format

Share Document