  We show that the qubit decoherence due to zero-temperature energy relaxation
can be almost completely suppressed by using the quantum uncollapsing
procedure. To protect a qubit state, a partial quantum measurement moves it
towards the ground state, where it is kept during the storage period, while the
second partial measurement restores the initial state. This procedure
preferentially selects the cases without energy decay events. Stronger
decoherence suppression requires smaller selection probability; a desired point
in this trade-off can be chosen by varying the measurement strength. The
experiment can be realized in a straightforward way using the superconducting
phase qubit.
