Carrier-wave Rabi flopping on radiatively coupled shallow donor transitions inn-type GaAs

Nonlinear Terahertz Studies of Ultrafast Quasiparticle Dynamics in Semiconductors

“…To overcome such problems, we apply a strong time-dependent electric field in the THz range on n-doped GaAs, so that only electrons contribute to the transport. The entire optical path of the THz beam is placed in vacuum (for experimental details, see Refs [58,62]). A few cycle THz pulse with a center frequency of 2 THz and a field strength in the range up to 300 kV/cm was generated by optical rectification of 25 fs pulses from a Ti:sapphire oscillator-amplifier laser system and excites the sample placed in the focus of a parabolic mirror.…”

“…A few cycle THz pulse with a center frequency of 2 THz and a field strength in the range up to 300 kV/cm was generated by optical rectification of 25 fs pulses from a Ti:sapphire oscillator-amplifier laser system and excites the sample placed in the focus of a parabolic mirror. As the thickness of our sample d ¼ 500 nm is much less than the THz wavelength l % 150 mm, all electrons in the sample experience the same driving field, which is identical to E tr ðtÞ [25,42,62]. With a further pair of parabolic mirrors, the electric field of the transmitted THz pulse is transferred to a thin ZnTe crystal, where it is measured via electro-optic sampling [44,63,64].…”

Applications of time-resolved terahertz spectroscopy in ultrafast carrier dynamics (Invited Paper)

“…For instance, Gaal et al managed to observe the ultrafast nonlinear response in GaAs governed by the internal motions of quasi-particles [40] . In n-type GaAs excited by intense THz pulses, they found a long-lived coherent THz emission centered at approximately 2 THz and carrier-wave Rabi oscillations between bound impurity levels [41,42] . Furthermore, they observed THz-induced interband tunneling of electrons when they studied ntype GaAs with THz electric field strength as high as 300 kV/cm [43] .…”

Nonlinear free-carrier velocity induced by intense terahertz pulse in photoexcited semiconductor materials

“…have been reported. It has been found that the intense THz electric field can produce an additional long-lived coherent THz emission [11] , and induce the carrier-wave Rabi oscillation between bound impurity levels [12] in doped GaAs. More recently, T. Kampfrath et al performed the manipulation on the coherent spin waves in antiferromagnetic NiO by the magnetic component of intense Single-cycle terahertz pulses [13] .…”

“…The developments of intense coherent THz source stimulated the explorations on the nonlinear effects of materials in THz frequency range in recent years [1][2][3][4][5][6][7][8][9][10][11][12][13][14] . The intense-THz induced exciting phenomena include dynamical Franz-Keldysh effect (DFKE) [5,6], cross-phase modulation [7] , ultrafast impact ionization [8,9] , photoluminescence quenching [10] etc.…”