Orientation and alignment echoes.
We present one of the simplest classical systems featuring the echo phenomenon-a collection of randomly oriented free rotors with dispersed rotational velocities. Following excitation by a pair of time-delayed impulsive kicks, the mean orientation or alignment of the ensemble exhibits multiple echoes and fractional echoes. We elucidate the mechanism of the echo formation by the kick-induced filamentation of phase space, and provide the first experimental demonstration of classical alignment echoes in a thermal gas of CO_{2} molecules excited by a pair of femtosecond laser pulses.
Laboratoire Interdisciplinaire CARNOT de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47870, 21078 Dijon, France.
G
G
Karras
Laboratoire Interdisciplinaire CARNOT de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47870, 21078 Dijon, France.
E
E
Hertz
Laboratoire Interdisciplinaire CARNOT de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47870, 21078 Dijon, France.
F
F
Billard
Laboratoire Interdisciplinaire CARNOT de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47870, 21078 Dijon, France.
B
B
Lavorel
Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA) CNRS (UMR 7583), Université Paris Est Créteil, Université Paris Diderot, Institut Pierre-Simon Laplace, Université Paris Est Créteil, 94010 Créteil Cedex, France.
J-M
JM
Hartmann
Laboratoire Interdisciplinaire CARNOT de Bourgogne, UMR 6303 CNRS-Université de Bourgogne, BP 47870, 21078 Dijon, France.
O
O
Faucher
Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel.
Erez
E
Gershnabel
Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel.
Yehiam
Y
Prior
Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel.
Ilya Sh
ISh
Averbukh