  Atomic clocks are typically operated by locking a local oscillator (LO) to a
single atomic ensemble. In this article we propose a scheme where the LO is
locked to several atomic ensembles instead of one. This results in an
exponential improvement compared to the conventional method and provides a
stability of the clock scaling as $(\alpha N)^{-m/2}$ with $N$ being the number
of atoms in each of the $m$ ensembles and $\alpha$ is a constant depending on
the protocol being used to lock the LO
