Accurate photon echo timing by optical freezing of exciton dephasing and rephasing in quantum dots

Abstract

Semiconductor quantum dots are excellent candidates for ultrafast coherent manipulation of qubits by laser pulses on picosecond timescales or even faster. In inhomogeneous ensembles a macroscopic optical polarization decays rapidly due to dephasing, which, however, is reversible in photon echoes carrying complete information about the coherent ensemble dynamics. Control of the echo emission time is mandatory for applications. Here, we propose a concept to reach this goal. In a two-pulse photon echo sequence, we apply an additional resonant control pulse with multiple of 2π area. Depending on its arrival time, the control slows down dephasing or rephasing of the exciton ensemble during its action. We demonstrate for self-assembled (In,Ga)As quantum dots that the photon echo emission time can be retarded or advanced by up to 5 ps relative to its nominal appearance time without control. This versatile protocol may be used to obtain significantly longer temporal shifts for suitably tailored control pulses.

Extending the time of coherent optical response in ensemble of singly-charged InGaAs quantum dots

“…In the case of 2PE, the amplitude is scanned as a function of 2τ 12 (blue points), while for 3PE the dependence on τ 23 is shown (green points). The exponential fit of two-pulse echo |P 2PE | ∝ exp{(−2τ 12 /T 2 )} gives T 2 = 0.45 ns which is in agreement with previous studies in (In,Ga)As/GaAs QDs [16,22,24]. The decay of 3PE has a more complex structure.…”

“…In solid-state systems based on color centers and rare earth ions, significant progress has been achieved in that respect [6][7][8][9][10][11]. Yet, the search for new systems where similar or alternative approaches can be pursued on much faster times scales is of great interest [12][13][14][15][16].…”

Destructive Photon Echo Formation in Six‐Wave Mixing Signals of a MoSe2Monolayer

“…It has been used to study different types of exciton dynamics, ranging from exciton‐exciton scattering [ 10 , 11 , 12 , 13 ] to exciton‐phonon coupling, [ 14 , 15 ] and it has been applied to 3D bulk, [ 10 , 16 , 17 ] 2D quantum well, [ 18 , 19 ] 1D nanowire, [ 20 ] and 0D quantum dot structures. [ 21 , 22 , 23 , 24 ] However, the technique is not restricted to solid state samples; it has also been applied to liquids. [ 25 , 26 , 27 ] In its classical form, the photon echo is based on a four‐wave mixing (FWM) process and therefore it constitutes a nonlinear process of third order (χ (3) ) in the low excitation limit.…”

Destructive photon echo formation in six-wave mixing signals of a MoSe$_2$ monolayer

“…First demonstrations were performed on ruby crystals [8,9], but the photon echo spectroscopy also has a long standing history in semiconductor optics. It has been used to study different types of exciton dynamics, ranging from exciton-exciton scattering [10,11,12,13] to exciton-phonon coupling [14,15], and it has been applied to three dimensional bulk [10,16,17], two dimensional quantum well [18,19], one dimensional nanowire [20], and zero dimensional quantum dot structures [21,22,23,24]. However, the technique is not restricted to solid state samples; it has also been applied to liquids [25,26,27].…”