Quantum beats of type-I and type-II excitons in an InxGa1−xAs/GaAs strained single quantum well

Abstract

We have investigated the quantum beat of the type-I heavy-hole (HH) and the type-II light-hole (LH) excitons in an In 0:15 Ga 0:85 As/GaAs strained single quantum well (SQW) using a reflection-type pump-probe technique. The type-II LH exciton consists of the electron and LH located in the In 0:15 Ga 0:85 As and GaAs layers, respectively. The energies of the type-I and the type-II excitons were evaluated with photoreflectance spectroscopy. The exciton states were calculated based on a variational method. The time-domain signals clearly show the oscillatory structure with the period corresponding to the splitting energy of the HH and the LH excitons. From the pump-energy dependence of the Fourier transform spectrum and intensity, it is concluded that the oscillation originates from the quantum beat of the type-I HH and the type-II LH excitons. V

A study on quantum beats of excitons in GaAs/AlGaAs circular cylindrical quantum wires

“…[35][36][37] The quantum beats of excitons in lowdimensional semiconductor structures were first investigated in semiconductor quantum wells. [38][39][40][41] Then, experimental measurements of this phenomenon are expanded to semiconductor quantum dot structures. 42,43) However, no studies in the field could be found so far discussing the quantum beats of excitons in semiconductor quantum wires.…”

Effects of non-exciton components excited by broadband pulses on quantum beats in a GaAs/AlAs multiple quantum well

“…Coherent exciton oscillations, such as quantum beats and Bloch oscillations, have been extensively studied to understand the ultrafast exciton dynamics 1 2 3 4 5 6 7 8 9 , the interaction of excitons with phonons 10 11 12 13 14 15 16 17 18 , the determination of the splitting energies in inhomogeneous systems 19 20 21 , and applications of ultrafast devices 22 23 24 . However, one problem has been the difficulty of generating a clear and long-lived oscillation.…”

Modulation of exciton states through resonant excitation by continuous wave lasers in a GaAs/AlAs multiple quantum well

“…However, in the case of exciton overlap, interesting coherent oscillation phenomena occur. For excitons with different energies, such as heavy-hole (HH) and light-hole (LH) excitons, the overlap of simultaneously created excitons has been investigated based on quantum beats using ultrashort pulse lasers, as quantum beats are a typical temporal oscillation phenomena [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Moreover, Bloch oscillations also occur as coherent oscillations due to exciton overlap [19][20][21][22].…”