Volume 77, Number 4, February 2007
Article Number 40001
Number of page(s) 5
Section General
Published online 08 February 2007
EPL, 77 (2007) 40001
DOI: 10.1209/0295-5075/77/40001

Towards a time reversal mirror for quantum systems

H. M. Pastawski1, E. P. Danieli1, H. L. Calvo1 and L. E. F. Foa Torres2

1  Facultad de Matemática, Astronomía y Física, Universidad Nacional de Córdoba - 5000 Córdoba, Argentina
2  CEA/DRFMC/SPSMS/GT and CEA Léti-MINATEC - 17 avenue des Martyrs, 38054 Grenoble, France

received 1 November 2006; accepted in final form 13 December 2006; published February 2007
published online 8 February 2007

The reversion of the time evolution of a quantum state can be achieved by changing the sign of the Hamiltonian as in the Loschmidt echo and polarization echo experiment in NMR. In this work we describe an alternative mechanism inspired by the acoustic time reversal mirror. By solving the inverse time problem in a discrete space we develop a new procedure, the perfect inverse filter. It achieves the exact time reversion in a given region by reinjecting a prescribed wave function at the region's boundary.

03.65.Wj - State reconstruction, quantum tomography.
03.67.-a - Quantum information.
43.20.+g - General linear acoustics.

© Europhysics Letters Association 2007