Late-time coarsening dynamics in a nematic liquid crystal

We have studied the coarsening dynamics of line defects in the uniaxial nematic liquid crystal 4-cyano-4'-n-pentylbiphenyl, subjected to a rapid pressure jump from the isotropic to the nematic phase. At late times, the density of disclination lines {ρ} is expected to scale with time as {ρ}{∝}t^-ν with {ν}=1. We have measured the scaling exponent to be {ν}=1.02±{}0.09 over the region 16160 mm^-2. In addition, we have measured the collapse of loops consisting of type-1/2 disclination lines. The loop radius r is expected to scale with time as r{∝}(t₀-t)^α, where {α}=1/2 and t₀ is the time at which the loop vanishes. We found {α} to be 0.50±{}0.03.