Photon echo Ultrafast in liquids using pulses longer than the electronic dephasing time

Hiroki Nakatsuka, Masahiro Fujiwara, R. Kuroda

Photon echoes with broad spectrum nanosecond laser pulses have been used to measure a femtosecond dephasing time (homogeneous transverse relaxation time) T2 of the S0↔1 transition of Cresyl Fast Violet molecules in a cellulose film. The measured T2 was much shorter at a shorter wavelength 5940A than that at a longer wavelength 6250A near the band edge.

Erik T. J. Nibbering, D. A. Wiersma, Koos Duppen

D. A. Wiersma, Wim P. de Boeij, M. Emde +1 more

Alexander N. Kosarev, Hendrik Rose, S. V. Poltavtsev +7 more

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 novel concept to reach this goal. In a two-pulse photon echo sequence, we apply an additional resonant control pulse with multiple of 2pi 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 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.

Alexander N. Kosarev, Hendrik Rose, S. V. Poltavtsev +7 more

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 2πarea. 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.

K.‐E. Süsse, W. Vogel, D.‐G. Welsch