Transition from the cholesteric storage mode to the nematic phase in critical restricted geometries

It is shown that a cholesteric liquid crystal, between parallel confining plates of spacing $2L$, prepared in the "storage mode" (helix axis parallel to plates) undergoes a transition to the nematic state when L is decreased to a critical value Lc. For 0<(L-Lc)Lc1 the pitch of the cholesteric helix diverges as ln(L-Lc).