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 linesis expected to scale with time as t- with =1. We have measured the scaling exponent to be =1.02±0.09 over the region 16<<160 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)±, where ±=1/2 and t0 is the time at which the loop vanishes. We found ± to be 0.50±0.03.