Short-cycle pulse sequence for dynamical decoupling of local fields and dipole-dipole interactions

We propose an alternate pulse sequence for dynamical averaging of the dipole-dipole interactions and inhomogeneity of the magnetic fields in the nuclear-spin system. The sequence contains a short cycle of the periodic resonant pulse excitation that offers new possibilities for implementing the long-lived multiqubit quantum memory on the condensed spin ensembles that are so important for the construction of a universal quantum computer and long-distance quantum communications.

Figure 1

Sequence of resonant rf pulses. The magnetic fields of these pulses are oriented along the $x(-x)$ axis [magenta up (down) lines] or along the $y(-y)$ axis [blue up (down) lines]; pulses 4 and 5 are closely spaced to each other.