  Two well-known mechanisms, one-axis twisting (OAT) and two-axis
countertwisting (TACT), generate spinsqueezed states dynamically. The latter
provides better spin squeezing (SS) but has not been demonstrated as the form
of its interaction does not occur naturally in known physical systems. Several
proposals for realizing effective TACT transformed from OAT require stringent
experimental conditions in order to overcome the resulting nonstationary
(oscillating) SS and continuously varying mean spin directions. This work
presents a simple scheme that solves both problems by freezing SS at an optimal
point and realizing effectively persistent SS by inhibiting further squeezing
dynamics. Explicit procedures are outlined for persistent SS of the TACT limit.
Protocols based on our scheme favorably relax experimental demands, which
significantly brighten the prospects for realizing TACT.
